diff --git a/.eslintignore b/.eslintignore
index 2c6ade0a3ffb..1da590fcf44b 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -87,8 +87,6 @@ devtools/client/framework/**
 devtools/client/inspector/markup/test/doc_markup_events_*.html
 devtools/client/inspector/rules/test/doc_media_queries.html
 devtools/client/memory/test/chrome/*.html
-devtools/client/netmonitor/test/**
-devtools/client/netmonitor/har/test/**
 devtools/client/performance/components/test/test_jit_optimizations_01.html
 devtools/client/projecteditor/**
 devtools/client/responsive.html/test/browser/touch.html
diff --git a/devtools/client/netmonitor/har/test/browser_net_har_copy_all_as_har.js b/devtools/client/netmonitor/har/test/browser_net_har_copy_all_as_har.js
index d51f18e7c4e1..a9344f46e056 100644
--- a/devtools/client/netmonitor/har/test/browser_net_har_copy_all_as_har.js
+++ b/devtools/client/netmonitor/har/test/browser_net_har_copy_all_as_har.js
@@ -11,7 +11,7 @@ add_task(function* () {
 
   info("Starting test... ");
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
+  let { gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/request-list-context-menu");
diff --git a/devtools/client/netmonitor/har/test/browser_net_har_post_data.js b/devtools/client/netmonitor/har/test/browser_net_har_post_data.js
index 207fd1964d59..a4f52af8ade5 100644
--- a/devtools/client/netmonitor/har/test/browser_net_har_post_data.js
+++ b/devtools/client/netmonitor/har/test/browser_net_har_post_data.js
@@ -12,7 +12,7 @@ add_task(function* () {
 
   info("Starting test... ");
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
+  let { gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/request-list-context-menu");
diff --git a/devtools/client/netmonitor/har/test/browser_net_har_throttle_upload.js b/devtools/client/netmonitor/har/test/browser_net_har_throttle_upload.js
index d45bb10e215d..94623bcfa192 100644
--- a/devtools/client/netmonitor/har/test/browser_net_har_throttle_upload.js
+++ b/devtools/client/netmonitor/har/test/browser_net_har_throttle_upload.js
@@ -16,7 +16,7 @@ function* throttleUploadTest(actuallyThrottle) {
 
   info("Starting test... (actuallyThrottle = " + actuallyThrottle + ")");
 
-  let { document, gStore, windowRequire, NetMonitorController } = monitor.panelWin;
+  let { gStore, windowRequire, NetMonitorController } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/request-list-context-menu");
diff --git a/devtools/client/netmonitor/har/test/html_har_post-data-test-page.html b/devtools/client/netmonitor/har/test/html_har_post-data-test-page.html
index 7542d8d240e9..203ae06bad68 100644
--- a/devtools/client/netmonitor/har/test/html_har_post-data-test-page.html
+++ b/devtools/client/netmonitor/har/test/html_har_post-data-test-page.html
@@ -16,22 +16,25 @@
     <p>HAR POST data test</p>
 
     <script type="text/javascript">
-      function post(aAddress, aData) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress, true);
+      /* exported executeTest, executeTest2 */
+      "use strict";
+
+      function post(address, data) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address, true);
         xhr.setRequestHeader("Content-Type", "application/json");
-        xhr.send(aData);
+        xhr.send(data);
       }
 
       function executeTest() {
-        var url = "html_har_post-data-test-page.html";
-        var data = "{'first': 'John', 'last': 'Doe'}";
+        const url = "html_har_post-data-test-page.html";
+        const data = "{'first': 'John', 'last': 'Doe'}";
         post(url, data);
       }
 
       function executeTest2(size) {
-        var url = "html_har_post-data-test-page.html";
-        var data = "x".repeat(size);
+        const url = "html_har_post-data-test-page.html";
+        const data = "x".repeat(size);
         post(url, data);
       }
     </script>
diff --git a/devtools/client/netmonitor/test/browser_net_autoscroll.js b/devtools/client/netmonitor/test/browser_net_autoscroll.js
index bdafc8aa4274..c84cc84122bb 100644
--- a/devtools/client/netmonitor/test/browser_net_autoscroll.js
+++ b/devtools/client/netmonitor/test/browser_net_autoscroll.js
@@ -66,7 +66,7 @@ add_task(function* () {
       info("Waiting for one network request");
       yield waitForNetworkEvents(monitor, 1);
       console.log(requestsContainer.scrollHeight);
-      console.log(requestsContainer.clientHeight)
+      console.log(requestsContainer.clientHeight);
       if (requestsContainer.scrollHeight > requestsContainer.clientHeight) {
         info("The list is long enough, returning");
         return;
diff --git a/devtools/client/netmonitor/test/browser_net_cause.js b/devtools/client/netmonitor/test/browser_net_cause.js
index ea353925d728..6f43a9b2d27b 100644
--- a/devtools/client/netmonitor/test/browser_net_cause.js
+++ b/devtools/client/netmonitor/test/browser_net_cause.js
@@ -38,14 +38,14 @@ const EXPECTED_REQUESTS = [
     url: EXAMPLE_URL + "xhr_request",
     causeType: "xhr",
     causeUri: CAUSE_URL,
-    stack: [{ fn: "performXhrRequest", file: CAUSE_FILE_NAME, line: 22 }]
+    stack: [{ fn: "performXhrRequest", file: CAUSE_FILE_NAME, line: 24 }]
   },
   {
     method: "GET",
     url: EXAMPLE_URL + "fetch_request",
     causeType: "fetch",
     causeUri: CAUSE_URL,
-    stack: [{ fn: "performFetchRequest", file: CAUSE_FILE_NAME, line: 26 }]
+    stack: [{ fn: "performFetchRequest", file: CAUSE_FILE_NAME, line: 28 }]
   },
   {
     method: "GET",
@@ -53,8 +53,8 @@ const EXPECTED_REQUESTS = [
     causeType: "fetch",
     causeUri: CAUSE_URL,
     stack: [
-      { fn: "performPromiseFetchRequest", file: CAUSE_FILE_NAME, line: 38 },
-      { fn: null, file: CAUSE_FILE_NAME, line: 37, asyncCause: "promise callback" },
+      { fn: "performPromiseFetchRequest", file: CAUSE_FILE_NAME, line: 40 },
+      { fn: null, file: CAUSE_FILE_NAME, line: 39, asyncCause: "promise callback" },
     ]
   },
   {
@@ -63,8 +63,8 @@ const EXPECTED_REQUESTS = [
     causeType: "fetch",
     causeUri: CAUSE_URL,
     stack: [
-      { fn: "performTimeoutFetchRequest", file: CAUSE_FILE_NAME, line: 40 },
-      { fn: "performPromiseFetchRequest", file: CAUSE_FILE_NAME, line: 39,
+      { fn: "performTimeoutFetchRequest", file: CAUSE_FILE_NAME, line: 42 },
+      { fn: "performPromiseFetchRequest", file: CAUSE_FILE_NAME, line: 41,
         asyncCause: "setTimeout handler" },
     ]
   },
@@ -73,7 +73,7 @@ const EXPECTED_REQUESTS = [
     url: EXAMPLE_URL + "beacon_request",
     causeType: "beacon",
     causeUri: CAUSE_URL,
-    stack: [{ fn: "performBeaconRequest", file: CAUSE_FILE_NAME, line: 30 }]
+    stack: [{ fn: "performBeaconRequest", file: CAUSE_FILE_NAME, line: 32 }]
   },
 ];
 
diff --git a/devtools/client/netmonitor/test/browser_net_charts-03.js b/devtools/client/netmonitor/test/browser_net_charts-03.js
index c72d04bc4efc..457ec96eb1c9 100644
--- a/devtools/client/netmonitor/test/browser_net_charts-03.js
+++ b/devtools/client/netmonitor/test/browser_net_charts-03.js
@@ -67,7 +67,6 @@ add_task(function* () {
   is(rows[0].querySelectorAll("span")[1].textContent, "label2header",
     "The second column of the header displays the correct text.");
 
-
   ok(rows[1].querySelector(".table-chart-row-box.chart-colored-blob"),
     "A colored blob exists for the firt row.");
   is(rows[1].querySelectorAll("span")[0].getAttribute("name"), "label1",
diff --git a/devtools/client/netmonitor/test/browser_net_clear.js b/devtools/client/netmonitor/test/browser_net_clear.js
index 15a38005928b..6bffb04d0200 100644
--- a/devtools/client/netmonitor/test/browser_net_clear.js
+++ b/devtools/client/netmonitor/test/browser_net_clear.js
@@ -14,7 +14,6 @@ add_task(function* () {
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let { EVENTS } = windowRequire("devtools/client/netmonitor/constants");
-  let detailsPane = document.querySelector("#details-pane");
   let detailsPanelToggleButton = document.querySelector(".network-details-panel-toggle");
   let clearButton = document.querySelector(".requests-list-clear-button");
 
diff --git a/devtools/client/netmonitor/test/browser_net_content-type.js b/devtools/client/netmonitor/test/browser_net_content-type.js
index f4b258ffe76f..eb60eddb07d9 100644
--- a/devtools/client/netmonitor/test/browser_net_content-type.js
+++ b/devtools/client/netmonitor/test/browser_net_content-type.js
@@ -41,8 +41,9 @@ add_task(function* () {
       fullMimeType: "text/xml; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 42),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(1),
@@ -55,8 +56,9 @@ add_task(function* () {
       fullMimeType: "text/css; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 34),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(2),
@@ -69,8 +71,9 @@ add_task(function* () {
       fullMimeType: "application/javascript; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 34),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(3),
@@ -83,26 +86,30 @@ add_task(function* () {
       fullMimeType: "application/json; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 29),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(4),
     "GET",
-    CONTENT_TYPE_SJS + "?fmt=bogus", {
+    CONTENT_TYPE_SJS + "?fmt=bogus",
+    {
       status: 404,
       statusText: "Not Found",
       type: "html",
       fullMimeType: "text/html; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 24),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(5),
     "GET",
-    TEST_IMAGE, {
+    TEST_IMAGE,
+    {
       fuzzyUrl: true,
       status: 200,
       statusText: "OK",
@@ -110,13 +117,15 @@ add_task(function* () {
       fullMimeType: "image/png",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 580),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(6),
     "GET",
-    CONTENT_TYPE_SJS + "?fmt=gzip", {
+    CONTENT_TYPE_SJS + "?fmt=gzip",
+    {
       status: 200,
       statusText: "OK",
       type: "plain",
@@ -124,7 +133,8 @@ add_task(function* () {
       transferred: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 73),
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeKB", 10.73),
       time: true
-    });
+    }
+  );
 
   yield selectIndexAndWaitForEditor(0);
   yield testResponseTab("xml");
diff --git a/devtools/client/netmonitor/test/browser_net_copy_as_curl.js b/devtools/client/netmonitor/test/browser_net_copy_as_curl.js
index 1267d7e2f3f5..caf04ad0479a 100644
--- a/devtools/client/netmonitor/test/browser_net_copy_as_curl.js
+++ b/devtools/client/netmonitor/test/browser_net_copy_as_curl.js
@@ -41,8 +41,7 @@ add_task(function* () {
     header("Cache-Control: no-cache")
   ];
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
-  let Actions = windowRequire("devtools/client/netmonitor/actions/index");
+  let { document } = monitor.panelWin;
 
   let wait = waitForNetworkEvents(monitor, 1);
   yield ContentTask.spawn(tab.linkedBrowser, SIMPLE_SJS, function* (url) {
diff --git a/devtools/client/netmonitor/test/browser_net_copy_image_as_data_uri.js b/devtools/client/netmonitor/test/browser_net_copy_image_as_data_uri.js
index 6beb81aa3a1a..6ada7fdd21c6 100644
--- a/devtools/client/netmonitor/test/browser_net_copy_image_as_data_uri.js
+++ b/devtools/client/netmonitor/test/browser_net_copy_image_as_data_uri.js
@@ -11,7 +11,7 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CONTENT_TYPE_WITHOUT_CACHE_URL);
   info("Starting test... ");
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
+  let { document } = monitor.panelWin;
 
   let wait = waitForNetworkEvents(monitor, CONTENT_TYPE_WITHOUT_CACHE_REQUESTS);
   yield ContentTask.spawn(tab.linkedBrowser, {}, function* () {
@@ -29,7 +29,7 @@ add_task(function* () {
     // toolbox.doc
     monitor.toolbox.doc
       .querySelector("#request-list-context-copy-image-as-data-uri").click();
- }, TEST_IMAGE_DATA_URI);
+  }, TEST_IMAGE_DATA_URI);
 
   ok(true, "Clipboard contains the currently selected image as data uri.");
 
diff --git a/devtools/client/netmonitor/test/browser_net_curl-utils.js b/devtools/client/netmonitor/test/browser_net_curl-utils.js
index a21df0a9e7cf..a34f28a3e149 100644
--- a/devtools/client/netmonitor/test/browser_net_curl-utils.js
+++ b/devtools/client/netmonitor/test/browser_net_curl-utils.js
@@ -13,7 +13,7 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CURL_UTILS_URL);
   info("Starting test... ");
 
-  let { document, gStore, windowRequire, gNetwork } = monitor.panelWin;
+  let { gStore, windowRequire, gNetwork } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let { getSortedRequests } = windowRequire("devtools/client/netmonitor/selectors/index");
 
diff --git a/devtools/client/netmonitor/test/browser_net_cyrillic-02.js b/devtools/client/netmonitor/test/browser_net_cyrillic-02.js
index 58094c8a631d..42ecdb1319e5 100644
--- a/devtools/client/netmonitor/test/browser_net_cyrillic-02.js
+++ b/devtools/client/netmonitor/test/browser_net_cyrillic-02.js
@@ -13,7 +13,6 @@ add_task(function* () {
   info("Starting test... ");
 
   let { document, gStore, windowRequire } = monitor.panelWin;
-  let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let {
     getDisplayedRequests,
     getSortedRequests,
diff --git a/devtools/client/netmonitor/test/browser_net_filter-04.js b/devtools/client/netmonitor/test/browser_net_filter-04.js
index 418a50dd66c2..b2327c36d535 100644
--- a/devtools/client/netmonitor/test/browser_net_filter-04.js
+++ b/devtools/client/netmonitor/test/browser_net_filter-04.js
@@ -30,7 +30,8 @@ const REQUESTS_WITH_MEDIA_AND_FLASH_AND_WS = REQUESTS_WITH_MEDIA_AND_FLASH.conca
 ]);
 
 add_task(function* () {
-  Services.prefs.setCharPref("devtools.netmonitor.filters", '["bogus", "js", "alsobogus"]');
+  Services.prefs.setCharPref("devtools.netmonitor.filters",
+                             '["bogus", "js", "alsobogus"]');
 
   let { monitor } = yield initNetMonitor(FILTERING_URL);
   info("Starting test... ");
diff --git a/devtools/client/netmonitor/test/browser_net_footer-summary.js b/devtools/client/netmonitor/test/browser_net_footer-summary.js
index 852c2f0a3392..65bd2d9cf38b 100644
--- a/devtools/client/netmonitor/test/browser_net_footer-summary.js
+++ b/devtools/client/netmonitor/test/browser_net_footer-summary.js
@@ -49,8 +49,9 @@ add_task(function* () {
   yield teardown(monitor);
 
   function testStatus() {
-    let value = document.querySelector(".requests-list-network-summary-button").textContent;
-   info("Current summary: " + value);
+    let value = document.querySelector(".requests-list-network-summary-button")
+                        .textContent;
+    info("Current summary: " + value);
 
     let state = gStore.getState();
     let totalRequestsCount = state.requests.requests.size;
diff --git a/devtools/client/netmonitor/test/browser_net_frame.js b/devtools/client/netmonitor/test/browser_net_frame.js
index c022a18a51cd..e45e5502cd17 100644
--- a/devtools/client/netmonitor/test/browser_net_frame.js
+++ b/devtools/client/netmonitor/test/browser_net_frame.js
@@ -39,14 +39,14 @@ const EXPECTED_REQUESTS_TOP = [
     url: EXAMPLE_URL + "xhr_request",
     causeType: "xhr",
     causeUri: TOP_URL,
-    stack: [{ fn: "performXhrRequest", file: TOP_FILE_NAME, line: 23 }]
+    stack: [{ fn: "performXhrRequest", file: TOP_FILE_NAME, line: 25 }]
   },
   {
     method: "GET",
     url: EXAMPLE_URL + "fetch_request",
     causeType: "fetch",
     causeUri: TOP_URL,
-    stack: [{ fn: "performFetchRequest", file: TOP_FILE_NAME, line: 27 }]
+    stack: [{ fn: "performFetchRequest", file: TOP_FILE_NAME, line: 29 }]
   },
   {
     method: "GET",
@@ -54,8 +54,8 @@ const EXPECTED_REQUESTS_TOP = [
     causeType: "fetch",
     causeUri: TOP_URL,
     stack: [
-      { fn: "performPromiseFetchRequest", file: TOP_FILE_NAME, line: 39 },
-      { fn: null, file: TOP_FILE_NAME, line: 38, asyncCause: "promise callback" },
+      { fn: "performPromiseFetchRequest", file: TOP_FILE_NAME, line: 41 },
+      { fn: null, file: TOP_FILE_NAME, line: 40, asyncCause: "promise callback" },
     ]
   },
   {
@@ -64,8 +64,8 @@ const EXPECTED_REQUESTS_TOP = [
     causeType: "fetch",
     causeUri: TOP_URL,
     stack: [
-      { fn: "performTimeoutFetchRequest", file: TOP_FILE_NAME, line: 41 },
-      { fn: "performPromiseFetchRequest", file: TOP_FILE_NAME, line: 40,
+      { fn: "performTimeoutFetchRequest", file: TOP_FILE_NAME, line: 43 },
+      { fn: "performPromiseFetchRequest", file: TOP_FILE_NAME, line: 42,
         asyncCause: "setTimeout handler" },
     ]
   },
@@ -74,7 +74,7 @@ const EXPECTED_REQUESTS_TOP = [
     url: EXAMPLE_URL + "beacon_request",
     causeType: "beacon",
     causeUri: TOP_URL,
-    stack: [{ fn: "performBeaconRequest", file: TOP_FILE_NAME, line: 31 }]
+    stack: [{ fn: "performBeaconRequest", file: TOP_FILE_NAME, line: 33 }]
   },
 ];
 
@@ -105,14 +105,14 @@ const EXPECTED_REQUESTS_SUB = [
     url: EXAMPLE_URL + "xhr_request",
     causeType: "xhr",
     causeUri: SUB_URL,
-    stack: [{ fn: "performXhrRequest", file: SUB_FILE_NAME, line: 22 }]
+    stack: [{ fn: "performXhrRequest", file: SUB_FILE_NAME, line: 24 }]
   },
   {
     method: "GET",
     url: EXAMPLE_URL + "fetch_request",
     causeType: "fetch",
     causeUri: SUB_URL,
-    stack: [{ fn: "performFetchRequest", file: SUB_FILE_NAME, line: 26 }]
+    stack: [{ fn: "performFetchRequest", file: SUB_FILE_NAME, line: 28 }]
   },
   {
     method: "GET",
@@ -120,8 +120,8 @@ const EXPECTED_REQUESTS_SUB = [
     causeType: "fetch",
     causeUri: SUB_URL,
     stack: [
-      { fn: "performPromiseFetchRequest", file: SUB_FILE_NAME, line: 38 },
-      { fn: null, file: SUB_FILE_NAME, line: 37, asyncCause: "promise callback" },
+      { fn: "performPromiseFetchRequest", file: SUB_FILE_NAME, line: 40 },
+      { fn: null, file: SUB_FILE_NAME, line: 39, asyncCause: "promise callback" },
     ]
   },
   {
@@ -130,8 +130,8 @@ const EXPECTED_REQUESTS_SUB = [
     causeType: "fetch",
     causeUri: SUB_URL,
     stack: [
-      { fn: "performTimeoutFetchRequest", file: SUB_FILE_NAME, line: 40 },
-      { fn: "performPromiseFetchRequest", file: SUB_FILE_NAME, line: 39,
+      { fn: "performTimeoutFetchRequest", file: SUB_FILE_NAME, line: 42 },
+      { fn: "performPromiseFetchRequest", file: SUB_FILE_NAME, line: 41,
         asyncCause: "setTimeout handler" },
     ]
   },
@@ -140,7 +140,7 @@ const EXPECTED_REQUESTS_SUB = [
     url: EXAMPLE_URL + "beacon_request",
     causeType: "beacon",
     causeUri: SUB_URL,
-    stack: [{ fn: "performBeaconRequest", file: SUB_FILE_NAME, line: 30 }]
+    stack: [{ fn: "performBeaconRequest", file: SUB_FILE_NAME, line: 32 }]
   },
 ];
 
diff --git a/devtools/client/netmonitor/test/browser_net_header-docs.js b/devtools/client/netmonitor/test/browser_net_header-docs.js
index 57a4f155b40b..475ac063488e 100644
--- a/devtools/client/netmonitor/test/browser_net_header-docs.js
+++ b/devtools/client/netmonitor/test/browser_net_header-docs.js
@@ -16,7 +16,6 @@ add_task(function* () {
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let {
-    getDisplayedRequests,
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/selectors/index");
 
@@ -40,17 +39,19 @@ add_task(function* () {
    * and only if a header is documented in MDN.
    */
   function testShowLearnMore(data) {
-    document.querySelectorAll(".properties-view .treeRow.stringRow").forEach((rowEl, index) => {
-      let headerName = rowEl.querySelectorAll(".treeLabelCell .treeLabel")[0].textContent;
+    let selector = ".properties-view .treeRow.stringRow";
+    document.querySelectorAll(selector).forEach((rowEl, index) => {
+      let headerName = rowEl.querySelectorAll(".treeLabelCell .treeLabel")[0]
+                            .textContent;
       let headerDocURL = getHeadersURL(headerName);
       let learnMoreEl = rowEl.querySelectorAll(".treeValueCell .learn-more-link");
 
       if (headerDocURL === null) {
         ok(learnMoreEl.length === 0,
-          "undocumented header does not include a \"Learn More\" button");
+           "undocumented header does not include a \"Learn More\" button");
       } else {
         ok(learnMoreEl[0].getAttribute("title") === headerDocURL,
-          "documented header includes a \"Learn More\" button with a link to MDN");
+           "documented header includes a \"Learn More\" button with a link to MDN");
       }
     });
   }
diff --git a/devtools/client/netmonitor/test/browser_net_icon-preview.js b/devtools/client/netmonitor/test/browser_net_icon-preview.js
index ac872f2f63ab..c3f91bcd90e0 100644
--- a/devtools/client/netmonitor/test/browser_net_icon-preview.js
+++ b/devtools/client/netmonitor/test/browser_net_icon-preview.js
@@ -64,7 +64,8 @@ add_task(function* () {
   function checkImageThumbnail() {
     is(document.querySelectorAll(".requests-list-icon[data-type=thumbnail]").length, 1,
       "There should be only one image request with a thumbnail displayed.");
-    is(document.querySelector(".requests-list-icon[data-type=thumbnail]").src, TEST_IMAGE_DATA_URI,
+    is(document.querySelector(".requests-list-icon[data-type=thumbnail]").src,
+      TEST_IMAGE_DATA_URI,
       "The image requests-list-icon thumbnail is displayed correctly.");
     is(document.querySelector(".requests-list-icon[data-type=thumbnail]").hidden, false,
       "The image requests-list-icon thumbnail should not be hidden.");
diff --git a/devtools/client/netmonitor/test/browser_net_image-tooltip.js b/devtools/client/netmonitor/test/browser_net_image-tooltip.js
index 43c031e37bd1..0db076392b43 100644
--- a/devtools/client/netmonitor/test/browser_net_image-tooltip.js
+++ b/devtools/client/netmonitor/test/browser_net_image-tooltip.js
@@ -16,10 +16,6 @@ add_task(function* test() {
   let { document, gStore, windowRequire, NetMonitorController } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let { ACTIVITY_TYPE, EVENTS } = windowRequire("devtools/client/netmonitor/constants");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
   let toolboxDoc = monitor.toolbox.doc;
 
   gStore.dispatch(Actions.batchEnable(false));
@@ -31,14 +27,12 @@ add_task(function* test() {
   yield onThumbnail;
 
   info("Checking the image thumbnail after a few requests were made...");
-  yield showTooltipAndVerify(toolboxDoc,
-    document.querySelectorAll(".request-list-item")[0]);
+  yield showTooltipAndVerify(document.querySelectorAll(".request-list-item")[0]);
 
   // Hide tooltip before next test, to avoid the situation that tooltip covers
   // the icon for the request of the next test.
   info("Checking the image thumbnail gets hidden...");
-  yield hideTooltipAndVerify(monitor.toolbox.doc,
-    document.querySelectorAll(".request-list-item")[0]);
+  yield hideTooltipAndVerify(document.querySelectorAll(".request-list-item")[0]);
 
   // +1 extra document reload
   onEvents = waitForNetworkEvents(monitor, IMAGE_TOOLTIP_REQUESTS + 1);
@@ -51,12 +45,12 @@ add_task(function* test() {
   yield onThumbnail;
 
   info("Checking the image thumbnail after a reload.");
-  yield showTooltipAndVerify(toolboxDoc,
-    document.querySelectorAll(".request-list-item")[1]);
+  yield showTooltipAndVerify(document.querySelectorAll(".request-list-item")[1]);
 
   info("Checking if the image thumbnail is hidden when mouse leaves the menu widget");
   let requestsListContents = document.querySelector(".requests-list-contents");
-  EventUtils.synthesizeMouse(requestsListContents, 0, 0, { type: "mouseout" }, monitor.panelWin);
+  EventUtils.synthesizeMouse(requestsListContents, 0, 0, { type: "mouseout" },
+                             monitor.panelWin);
   yield waitUntil(() => !toolboxDoc.querySelector(".tooltip-container.tooltip-visible"));
 
   yield teardown(monitor);
@@ -71,9 +65,9 @@ add_task(function* test() {
    * Show a tooltip on the {target} and verify that it was displayed
    * with the expected content.
    */
-  function* showTooltipAndVerify(toolboxDoc, target) {
+  function* showTooltipAndVerify(target) {
     let anchor = target.querySelector(".requests-list-file");
-    yield showTooltipOn(toolboxDoc, anchor);
+    yield showTooltipOn(anchor);
 
     info("Tooltip was successfully opened for the image request.");
     is(toolboxDoc.querySelector(".tooltip-panel img").src, TEST_IMAGE_DATA_URI,
@@ -84,7 +78,7 @@ add_task(function* test() {
    * Trigger a tooltip over an element by sending mousemove event.
    * @return a promise that resolves when the tooltip is shown
    */
-  function* showTooltipOn(toolboxDoc, element) {
+  function* showTooltipOn(element) {
     let win = element.ownerDocument.defaultView;
     EventUtils.synthesizeMouseAtCenter(element, { type: "mousemove" }, win);
     yield waitUntil(() => toolboxDoc.querySelector(".tooltip-panel img"));
@@ -93,13 +87,14 @@ add_task(function* test() {
   /**
    * Hide a tooltip on the {target} and verify that it was closed.
    */
-  function* hideTooltipAndVerify(toolboxDoc, target) {
+  function* hideTooltipAndVerify(target) {
     // Hovering over the "method" column hides the tooltip.
     let anchor = target.querySelector(".requests-list-method");
     let win = anchor.ownerDocument.defaultView;
     EventUtils.synthesizeMouseAtCenter(anchor, { type: "mousemove" }, win);
 
-    yield waitUntil(() => !toolboxDoc.querySelector(".tooltip-container.tooltip-visible"));
+    yield waitUntil(
+      () => !toolboxDoc.querySelector(".tooltip-container.tooltip-visible"));
     info("Tooltip was successfully closed.");
   }
 });
diff --git a/devtools/client/netmonitor/test/browser_net_json-null.js b/devtools/client/netmonitor/test/browser_net_json-null.js
index 82b87d3a2477..877881e0ca2b 100644
--- a/devtools/client/netmonitor/test/browser_net_json-null.js
+++ b/devtools/client/netmonitor/test/browser_net_json-null.js
@@ -15,10 +15,6 @@ add_task(function* () {
 
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_open_request_in_tab.js b/devtools/client/netmonitor/test/browser_net_open_request_in_tab.js
index 842efb7df23a..4c60887d0d3c 100644
--- a/devtools/client/netmonitor/test/browser_net_open_request_in_tab.js
+++ b/devtools/client/netmonitor/test/browser_net_open_request_in_tab.js
@@ -13,10 +13,6 @@ add_task(function* () {
 
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_persistent_logs.js b/devtools/client/netmonitor/test/browser_net_persistent_logs.js
index 64bc202370cc..789b4e9a7450 100644
--- a/devtools/client/netmonitor/test/browser_net_persistent_logs.js
+++ b/devtools/client/netmonitor/test/browser_net_persistent_logs.js
@@ -12,7 +12,7 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(SINGLE_GET_URL);
   info("Starting test... ");
 
-  let { document, windowRequire } = monitor.panelWin;
+  let { document } = monitor.panelWin;
 
   Services.prefs.setBoolPref("devtools.webconsole.persistlog", false);
 
diff --git a/devtools/client/netmonitor/test/browser_net_post-data-01.js b/devtools/client/netmonitor/test/browser_net_post-data-01.js
index bb26d3ec7399..277a929b168f 100644
--- a/devtools/client/netmonitor/test/browser_net_post-data-01.js
+++ b/devtools/client/netmonitor/test/browser_net_post-data-01.js
@@ -44,8 +44,9 @@ add_task(function* () {
       fullMimeType: "text/plain; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 12),
       time: true
-    });
-   verifyRequestItemTarget(
+    }
+  );
+  verifyRequestItemTarget(
     document,
     getDisplayedRequests(gStore.getState()),
     getSortedRequests(gStore.getState()).get(1),
@@ -58,7 +59,8 @@ add_task(function* () {
       fullMimeType: "text/plain; charset=utf-8",
       size: L10N.getFormatStrWithNumbers("networkMenu.sizeB", 12),
       time: true
-    });
+    }
+  );
 
   // Wait for all tree sections updated by react
   wait = waitForDOM(document, "#params-panel .tree-section", 2);
@@ -107,15 +109,18 @@ add_task(function* () {
       L10N.getStr(type == "urlencoded" ? "paramsFormData" : "paramsPostPayload"),
       "The post section doesn't have the correct title.");
 
-    let labels = tabpanel.querySelectorAll("tr:not(.tree-section) .treeLabelCell .treeLabel");
-    let values = tabpanel.querySelectorAll("tr:not(.tree-section) .treeValueCell .objectBox");
+    let labels = tabpanel
+      .querySelectorAll("tr:not(.tree-section) .treeLabelCell .treeLabel");
+    let values = tabpanel
+      .querySelectorAll("tr:not(.tree-section) .treeValueCell .objectBox");
 
     is(labels[0].textContent, "foo", "The first query param name was incorrect.");
     is(values[0].textContent, "\"bar\"", "The first query param value was incorrect.");
     is(labels[1].textContent, "baz", "The second query param name was incorrect.");
     is(values[1].textContent, "\"42\"", "The second query param value was incorrect.");
     is(labels[2].textContent, "type", "The third query param name was incorrect.");
-    is(values[2].textContent, "\"" + type + "\"", "The third query param value was incorrect.");
+    is(values[2].textContent, "\"" + type + "\"",
+      "The third query param value was incorrect.");
 
     if (type == "urlencoded") {
       checkVisibility("params");
@@ -129,7 +134,8 @@ add_task(function* () {
 
       is(labels.length, 3, "There should be 3 param values displayed in this tabpanel.");
 
-      let text = editorFrames[0].contentDocument.querySelector(".CodeMirror-code").textContent;
+      let text = editorFrames[0].contentDocument.querySelector(".CodeMirror-code")
+                                                .textContent;
 
       ok(text.includes("Content-Disposition: form-data; name=\"text\""),
         "The text shown in the source editor is incorrect (1.1).");
diff --git a/devtools/client/netmonitor/test/browser_net_post-data-02.js b/devtools/client/netmonitor/test/browser_net_post-data-02.js
index 3382deaec316..503fd096305d 100644
--- a/devtools/client/netmonitor/test/browser_net_post-data-02.js
+++ b/devtools/client/netmonitor/test/browser_net_post-data-02.js
@@ -16,10 +16,6 @@ add_task(function* () {
 
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_prefs-reload.js b/devtools/client/netmonitor/test/browser_net_prefs-reload.js
index fb27d49d776b..4a92350065d1 100644
--- a/devtools/client/netmonitor/test/browser_net_prefs-reload.js
+++ b/devtools/client/netmonitor/test/browser_net_prefs-reload.js
@@ -11,7 +11,8 @@ add_task(function* () {
   let { monitor } = yield initNetMonitor(SIMPLE_URL);
   let { getRequestFilterTypes } = monitor.panelWin
     .windowRequire("devtools/client/netmonitor/selectors/index");
-  let Actions = monitor.panelWin.windowRequire("devtools/client/netmonitor/actions/index");
+  let Actions = monitor.panelWin
+    .windowRequire("devtools/client/netmonitor/actions/index");
   info("Starting test... ");
 
   // This test reopens the network monitor a bunch of times, for different
@@ -22,7 +23,8 @@ add_task(function* () {
   // since the tool is reopened a bunch of times during this test
   // and the instances will differ.
   let getDoc = () => monitor.panelWin.document;
-  let getPrefs = () => monitor.panelWin.windowRequire("devtools/client/netmonitor/utils/prefs").Prefs;
+  let getPrefs = () => monitor.panelWin
+    .windowRequire("devtools/client/netmonitor/utils/prefs").Prefs;
   let getStore = () => monitor.panelWin.gStore;
   let getState = () => getStore().getState();
 
@@ -44,15 +46,19 @@ add_task(function* () {
       newValue: ~~(Math.random() * 200 + 100),
       validateValue: () =>
         getDoc().querySelector(".monitor-panel .split-box .controlled").clientWidth,
-      modifyFrontend: (value) =>
-        getDoc().querySelector(".monitor-panel .split-box .controlled").style.width = `${value}px`,
+      modifyFrontend: function (value) {
+        getDoc().querySelector(".monitor-panel .split-box .controlled")
+                .style.width = `${value}px`;
+      }
     },
     networkDetailsHeight: {
       newValue: ~~(Math.random() * 300 + 100),
       validateValue: () =>
         getDoc().querySelector(".monitor-panel .split-box .controlled").clientHeight,
-      modifyFrontend: (value) =>
-        getDoc().querySelector(".monitor-panel .split-box .controlled").style.height = `${value}px`
+      modifyFrontend: function (value) {
+        getDoc().querySelector(".monitor-panel .split-box .controlled")
+                .style.height = `${value}px`;
+      }
     }
     /* add more prefs here... */
   };
@@ -80,7 +86,7 @@ add_task(function* () {
     for (let name in prefsToCheck) {
       if ((isVerticalSplitter && name === "networkDetailsHeight") ||
           (!isVerticalSplitter && name === "networkDetailsWidth")) {
-        continue
+        continue;
       }
 
       let currentValue = getPrefs()[name];
@@ -100,7 +106,7 @@ add_task(function* () {
     for (let name in prefsToCheck) {
       if ((isVerticalSplitter && name === "networkDetailsHeight") ||
           (!isVerticalSplitter && name === "networkDetailsWidth")) {
-        continue
+        continue;
       }
 
       let currentValue = getPrefs()[name];
@@ -127,7 +133,7 @@ add_task(function* () {
     for (let name in prefsToCheck) {
       if ((isVerticalSplitter && name === "networkDetailsHeight") ||
           (!isVerticalSplitter && name === "networkDetailsWidth")) {
-        continue
+        continue;
       }
 
       let currentValue = getPrefs()[name];
@@ -150,7 +156,7 @@ add_task(function* () {
     for (let name in prefsToCheck) {
       if ((isVerticalSplitter && name === "networkDetailsHeight") ||
           (!isVerticalSplitter && name === "networkDetailsWidth")) {
-        continue
+        continue;
       }
 
       let currentValue = getPrefs()[name];
diff --git a/devtools/client/netmonitor/test/browser_net_reload-markers.js b/devtools/client/netmonitor/test/browser_net_reload-markers.js
index 1a7953b9cb01..792b02ea2eeb 100644
--- a/devtools/client/netmonitor/test/browser_net_reload-markers.js
+++ b/devtools/client/netmonitor/test/browser_net_reload-markers.js
@@ -11,7 +11,7 @@ add_task(function* () {
   let { monitor } = yield initNetMonitor(SIMPLE_URL);
   info("Starting test... ");
 
-  let { document, windowRequire } = monitor.panelWin;
+  let { document } = monitor.panelWin;
   let button = document.querySelector(".requests-list-reload-notice-button");
   button.click();
 
diff --git a/devtools/client/netmonitor/test/browser_net_resend.js b/devtools/client/netmonitor/test/browser_net_resend.js
index e52c3c9adbf7..6e08dec9be64 100644
--- a/devtools/client/netmonitor/test/browser_net_resend.js
+++ b/devtools/client/netmonitor/test/browser_net_resend.js
@@ -74,7 +74,7 @@ add_task(function* () {
   /*
    * Test that the New Request form was populated correctly
    */
-  function testCustomForm(data) {
+  function* testCustomForm(data) {
     yield waitUntil(() => document.querySelector(".custom-request-panel"));
     is(document.getElementById("custom-method-value").value, data.method,
        "new request form showing correct method");
diff --git a/devtools/client/netmonitor/test/browser_net_resend_cors.js b/devtools/client/netmonitor/test/browser_net_resend_cors.js
index b4f1ab317bab..cab3854cda20 100644
--- a/devtools/client/netmonitor/test/browser_net_resend_cors.js
+++ b/devtools/client/netmonitor/test/browser_net_resend_cors.js
@@ -12,10 +12,9 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CORS_URL);
   info("Starting test... ");
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
+  let { gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let {
-    getDisplayedRequests,
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/selectors/index");
 
@@ -44,7 +43,7 @@ add_task(function* () {
   let onRequests = waitForNetworkEvents(monitor, 1, 0);
   ITEMS.forEach((item) => {
     info(`Selecting the ${item.method} request`);
-    gStore.dispatch(Actions.selectRequest(item.id))
+    gStore.dispatch(Actions.selectRequest(item.id));
 
     info("Cloning the selected request into a custom clone");
     gStore.dispatch(Actions.cloneSelectedRequest());
diff --git a/devtools/client/netmonitor/test/browser_net_resend_headers.js b/devtools/client/netmonitor/test/browser_net_resend_headers.js
index d118cfc3e81e..011136ef20d7 100644
--- a/devtools/client/netmonitor/test/browser_net_resend_headers.js
+++ b/devtools/client/netmonitor/test/browser_net_resend_headers.js
@@ -11,10 +11,9 @@ add_task(function* () {
   let { monitor } = yield initNetMonitor(SIMPLE_SJS);
   info("Starting test... ");
 
-  let { document, gStore, windowRequire, NetMonitorController } = monitor.panelWin;
+  let { gStore, windowRequire, NetMonitorController } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let {
-    getDisplayedRequests,
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/selectors/index");
 
diff --git a/devtools/client/netmonitor/test/browser_net_security-details.js b/devtools/client/netmonitor/test/browser_net_security-details.js
index 5d174d42d5c3..ef324d723bc3 100644
--- a/devtools/client/netmonitor/test/browser_net_security-details.js
+++ b/devtools/client/netmonitor/test/browser_net_security-details.js
@@ -46,8 +46,8 @@ add_task(function* () {
 
   // Host
   is(tabpanel.querySelectorAll(".treeLabel.objectLabel")[1].textContent,
-    "Host example.com:",
-    "Label has the expected value.");
+     "Host example.com:",
+     "Label has the expected value.");
   is(textboxes[2].value, "Disabled", "Label has the expected value.");
   is(textboxes[3].value, "Disabled", "Label has the expected value.");
 
@@ -56,7 +56,8 @@ add_task(function* () {
   is(textboxes[5].value, "<Not Available>", "Label has the expected value.");
   is(textboxes[6].value, "<Not Available>", "Label has the expected value.");
 
-  is(textboxes[7].value, "Temporary Certificate Authority", "Label has the expected value.");
+  is(textboxes[7].value, "Temporary Certificate Authority",
+     "Label has the expected value.");
   is(textboxes[8].value, "Mozilla Testing", "Label has the expected value.");
   is(textboxes[9].value, "Profile Guided Optimization", "Label has the expected value.");
 
diff --git a/devtools/client/netmonitor/test/browser_net_security-icon-click.js b/devtools/client/netmonitor/test/browser_net_security-icon-click.js
index 5464e1499e1a..4b3cbe22bbb5 100644
--- a/devtools/client/netmonitor/test/browser_net_security-icon-click.js
+++ b/devtools/client/netmonitor/test/browser_net_security-icon-click.js
@@ -11,10 +11,6 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CUSTOM_GET_URL);
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
@@ -54,6 +50,7 @@ add_task(function* () {
     info("Clicking security icon of the first request and waiting for panel update.");
     EventUtils.synthesizeMouseAtCenter(icon, {}, monitor.panelWin);
 
-    ok(document.querySelector("#security-tab[aria-selected=true]"), "Security tab is selected.");
+    ok(document.querySelector("#security-tab[aria-selected=true]"),
+       "Security tab is selected.");
   }
 });
diff --git a/devtools/client/netmonitor/test/browser_net_security-redirect.js b/devtools/client/netmonitor/test/browser_net_security-redirect.js
index f56b2b3c0fd5..ebf1212691e6 100644
--- a/devtools/client/netmonitor/test/browser_net_security-redirect.js
+++ b/devtools/client/netmonitor/test/browser_net_security-redirect.js
@@ -12,10 +12,6 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CUSTOM_GET_URL);
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
@@ -25,13 +21,13 @@ add_task(function* () {
   });
   yield wait;
 
-  is(gStore.getState().requests.requests.size, 2, "There were two requests due to redirect.");
+  is(gStore.getState().requests.requests.size, 2,
+     "There were two requests due to redirect.");
 
-  let initial = getSortedRequests(gStore.getState()).get(0);
-  let redirect = getSortedRequests(gStore.getState()).get(1);
-
-  let initialSecurityIcon = document.querySelectorAll(".requests-security-state-icon")[0];
-  let redirectSecurityIcon = document.querySelectorAll(".requests-security-state-icon")[1];
+  let [
+    initialSecurityIcon,
+    redirectSecurityIcon,
+  ] = document.querySelectorAll(".requests-security-state-icon");
 
   ok(initialSecurityIcon.classList.contains("security-state-insecure"),
      "Initial request was marked insecure.");
diff --git a/devtools/client/netmonitor/test/browser_net_security-state.js b/devtools/client/netmonitor/test/browser_net_security-state.js
index 2d937cf25b72..e1fd787ef07c 100644
--- a/devtools/client/netmonitor/test/browser_net_security-state.js
+++ b/devtools/client/netmonitor/test/browser_net_security-state.js
@@ -19,10 +19,6 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CUSTOM_GET_URL);
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_security-tab-visibility.js b/devtools/client/netmonitor/test/browser_net_security-tab-visibility.js
index 503d63453256..6e7aab5f4529 100644
--- a/devtools/client/netmonitor/test/browser_net_security-tab-visibility.js
+++ b/devtools/client/netmonitor/test/browser_net_security-tab-visibility.js
@@ -34,7 +34,9 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CUSTOM_GET_URL);
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let { getSelectedRequest } = windowRequire("devtools/client/netmonitor/selectors/index");
+  let {
+    getSelectedRequest,
+  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_send-beacon.js b/devtools/client/netmonitor/test/browser_net_send-beacon.js
index 343816bb4750..c11ba2e7e5b8 100644
--- a/devtools/client/netmonitor/test/browser_net_send-beacon.js
+++ b/devtools/client/netmonitor/test/browser_net_send-beacon.js
@@ -9,7 +9,7 @@
 
 add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(SEND_BEACON_URL);
- let { gStore, windowRequire } = monitor.panelWin;
+  let { gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let { getSortedRequests } = windowRequire("devtools/client/netmonitor/selectors/index");
 
diff --git a/devtools/client/netmonitor/test/browser_net_simple-request-data.js b/devtools/client/netmonitor/test/browser_net_simple-request-data.js
index 60f96ca998ef..44dc550de315 100644
--- a/devtools/client/netmonitor/test/browser_net_simple-request-data.js
+++ b/devtools/client/netmonitor/test/browser_net_simple-request-data.js
@@ -223,12 +223,15 @@ function test() {
 
       ok(requestItem.responseContent,
         "There should be a responseContent data available.");
+      // eslint-disable-next-line mozilla/no-cpows-in-tests
       is(requestItem.responseContent.content.mimeType,
         "text/plain; charset=utf-8",
         "The responseContent data has an incorrect |content.mimeType| property.");
+      // eslint-disable-next-line mozilla/no-cpows-in-tests
       is(requestItem.responseContent.content.text,
         "Hello world!",
         "The responseContent data has an incorrect |content.text| property.");
+      // eslint-disable-next-line mozilla/no-cpows-in-tests
       is(requestItem.responseContent.content.size,
         12,
         "The responseContent data has an incorrect |content.size| property.");
diff --git a/devtools/client/netmonitor/test/browser_net_simple-request-details.js b/devtools/client/netmonitor/test/browser_net_simple-request-details.js
index 43d119111096..55f48a07851a 100644
--- a/devtools/client/netmonitor/test/browser_net_simple-request-details.js
+++ b/devtools/client/netmonitor/test/browser_net_simple-request-details.js
@@ -13,13 +13,14 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(SIMPLE_SJS);
   info("Starting test... ");
 
-  let { document, gStore, windowRequire } = monitor.panelWin;
+  let { document, gStore, windowRequire, NetMonitorView } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
   let { EVENTS } = windowRequire("devtools/client/netmonitor/constants");
   let {
-    getDisplayedRequests,
+    getSelectedRequest,
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/selectors/index");
+  let Editor = require("devtools/client/sourceeditor/editor");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_simple-request.js b/devtools/client/netmonitor/test/browser_net_simple-request.js
index a8de768755e7..a7cbca9b7b5c 100644
--- a/devtools/client/netmonitor/test/browser_net_simple-request.js
+++ b/devtools/client/netmonitor/test/browser_net_simple-request.js
@@ -18,11 +18,6 @@ add_task(function* () {
 
   let { document, gStore, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/actions/index");
-  let { EVENTS } = windowRequire("devtools/client/netmonitor/constants");
-  let {
-    getDisplayedRequests,
-    getSortedRequests,
-  } = windowRequire("devtools/client/netmonitor/selectors/index");
 
   gStore.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_statistics-01.js b/devtools/client/netmonitor/test/browser_net_statistics-01.js
index 85094d2f198e..b19e749cce23 100644
--- a/devtools/client/netmonitor/test/browser_net_statistics-01.js
+++ b/devtools/client/netmonitor/test/browser_net_statistics-01.js
@@ -27,21 +27,25 @@ add_task(function* () {
   info("Waiting for placeholder to display");
 
   yield waitUntil(
-    () => document.querySelectorAll(".pie-chart-container[placeholder=true]").length == 2);
+    () => document.querySelectorAll(".pie-chart-container[placeholder=true]")
+                  .length == 2);
   ok(true, "Two placeholder pie charts appear to be rendered correctly.");
 
   yield waitUntil(
-    () => document.querySelectorAll(".table-chart-container[placeholder=true]").length == 2);
+    () => document.querySelectorAll(".table-chart-container[placeholder=true]")
+                  .length == 2);
   ok(true, "Two placeholde table charts appear to be rendered correctly.");
 
   info("Waiting for chart to display");
 
   yield waitUntil(
-    () => document.querySelectorAll(".pie-chart-container:not([placeholder=true])").length == 2);
+    () => document.querySelectorAll(".pie-chart-container:not([placeholder=true])")
+                  .length == 2);
   ok(true, "Two real pie charts appear to be rendered correctly.");
 
   yield waitUntil(
-    () => document.querySelectorAll(".table-chart-container:not([placeholder=true])").length == 2);
+    () => document.querySelectorAll(".table-chart-container:not([placeholder=true])")
+                  .length == 2);
   ok(true, "Two real table charts appear to be rendered correctly.");
 
   yield teardown(monitor);
diff --git a/devtools/client/netmonitor/test/browser_net_statistics-02.js b/devtools/client/netmonitor/test/browser_net_statistics-02.js
index 65d1e8b06a74..9ffd7bc28f6e 100644
--- a/devtools/client/netmonitor/test/browser_net_statistics-02.js
+++ b/devtools/client/netmonitor/test/browser_net_statistics-02.js
@@ -35,7 +35,8 @@ add_task(function* () {
     "The main panel is switched to the statistics panel.");
 
   yield waitUntil(
-    () => document.querySelectorAll(".pie-chart-container:not([placeholder=true])").length == 2);
+    () => document.querySelectorAll(".pie-chart-container:not([placeholder=true])")
+                  .length == 2);
   ok(true, "Two real pie charts appear to be rendered correctly.");
 
   EventUtils.sendMouseEvent({ type: "click" },
diff --git a/devtools/client/netmonitor/test/browser_net_throttle.js b/devtools/client/netmonitor/test/browser_net_throttle.js
index 9a027b4d360f..a39b9019f3e1 100644
--- a/devtools/client/netmonitor/test/browser_net_throttle.js
+++ b/devtools/client/netmonitor/test/browser_net_throttle.js
@@ -14,8 +14,7 @@ function* throttleTest(actuallyThrottle) {
   requestLongerTimeout(2);
 
   let { monitor } = yield initNetMonitor(SIMPLE_URL);
-  let { document, gStore, windowRequire, NetMonitorController } = monitor.panelWin;
-  let Actions = windowRequire("devtools/client/netmonitor/actions/index");
+  let { gStore, windowRequire, NetMonitorController } = monitor.panelWin;
   let { ACTIVITY_TYPE } = windowRequire("devtools/client/netmonitor/constants");
   let { EVENTS } = windowRequire("devtools/client/netmonitor/constants");
   let {
diff --git a/devtools/client/netmonitor/test/browser_net_timing-division.js b/devtools/client/netmonitor/test/browser_net_timing-division.js
index d6b174ba4e66..a0dd7b18f6f7 100644
--- a/devtools/client/netmonitor/test/browser_net_timing-division.js
+++ b/devtools/client/netmonitor/test/browser_net_timing-division.js
@@ -39,20 +39,21 @@ add_task(function* () {
   secDivs.forEach(div => info(`Second division: ${div.textContent}`));
   minDivs.forEach(div => info(`Minute division: ${div.textContent}`));
 
-  is(gStore.getState().requests.requests.size, 2, "There should be only two requests made.");
+  is(gStore.getState().requests.requests.size, 2,
+     "There should be only two requests made.");
 
   let firstRequest = getSortedRequests(gStore.getState()).get(0);
   let lastRequest = getSortedRequests(gStore.getState()).get(1);
 
   info("First request happened at: " +
-    firstRequest.responseHeaders.headers.find(e => e.name == "Date").value);
+       firstRequest.responseHeaders.headers.find(e => e.name == "Date").value);
   info("Last request happened at: " +
-    lastRequest.responseHeaders.headers.find(e => e.name == "Date").value);
+       lastRequest.responseHeaders.headers.find(e => e.name == "Date").value);
 
   ok(secDivs.length,
-    "There should be at least one division on the seconds time scale.");
+     "There should be at least one division on the seconds time scale.");
   ok(secDivs[0].textContent.match(/\d+\.\d{2}\s\w+/),
-    "The division on the seconds time scale looks legit.");
+     "The division on the seconds time scale looks legit.");
 
   return teardown(monitor);
 });
diff --git a/devtools/client/netmonitor/test/head.js b/devtools/client/netmonitor/test/head.js
index 13585517ca28..5da452e3afba 100644
--- a/devtools/client/netmonitor/test/head.js
+++ b/devtools/client/netmonitor/test/head.js
@@ -2,6 +2,9 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 /* import-globals-from ../../framework/test/shared-head.js */
+/* exported Toolbox, restartNetMonitor, teardown, waitForExplicitFinish,
+   verifyRequestItemTarget, waitFor, testFilterButtons, loadCommonFrameScript,
+   performRequestsInContent, waitForNetworkEvents */
 
 "use strict";
 
@@ -11,7 +14,7 @@ Services.scriptloader.loadSubScript(
   this);
 
 const { EVENTS } = require("devtools/client/netmonitor/constants");
-var { Toolbox } = require("devtools/client/framework/toolbox");
+let { Toolbox } = require("devtools/client/framework/toolbox");
 const {
   decodeUnicodeUrl,
   getUrlBaseName,
@@ -19,6 +22,7 @@ const {
   getUrlHost,
 } = require("devtools/client/netmonitor/utils/request-utils");
 
+/* eslint-disable no-unused-vars, max-len */
 const EXAMPLE_URL = "http://example.com/browser/devtools/client/netmonitor/test/";
 const HTTPS_EXAMPLE_URL = "https://example.com/browser/devtools/client/netmonitor/test/";
 
@@ -69,6 +73,7 @@ const TEST_IMAGE = EXAMPLE_URL + "test-image.png";
 const TEST_IMAGE_DATA_URI = "data:image/png;base64,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";
 
 const FRAME_SCRIPT_UTILS_URL = "chrome://devtools/content/shared/frame-script-utils.js";
+/* eslint-enable no-unused-vars, max-len */
 
 // All tests are asynchronous.
 waitForExplicitFinish();
@@ -91,45 +96,45 @@ registerCleanupFunction(() => {
   Services.prefs.clearUserPref("devtools.cache.disabled");
 });
 
-function waitForNavigation(aTarget) {
+function waitForNavigation(target) {
   let deferred = promise.defer();
-  aTarget.once("will-navigate", () => {
-    aTarget.once("navigate", () => {
+  target.once("will-navigate", () => {
+    target.once("navigate", () => {
       deferred.resolve();
     });
   });
   return deferred.promise;
 }
 
-function reconfigureTab(aTarget, aOptions) {
+function reconfigureTab(target, options) {
   let deferred = promise.defer();
-  aTarget.activeTab.reconfigure(aOptions, deferred.resolve);
+  target.activeTab.reconfigure(options, deferred.resolve);
   return deferred.promise;
 }
 
-function toggleCache(aTarget, aDisabled) {
-  let options = { cacheDisabled: aDisabled, performReload: true };
-  let navigationFinished = waitForNavigation(aTarget);
+function toggleCache(target, disabled) {
+  let options = { cacheDisabled: disabled, performReload: true };
+  let navigationFinished = waitForNavigation(target);
 
   // Disable the cache for any toolbox that it is opened from this point on.
-  Services.prefs.setBoolPref("devtools.cache.disabled", aDisabled);
+  Services.prefs.setBoolPref("devtools.cache.disabled", disabled);
 
-  return reconfigureTab(aTarget, options).then(() => navigationFinished);
+  return reconfigureTab(target, options).then(() => navigationFinished);
 }
 
-function initNetMonitor(aUrl, aWindow, aEnableCache) {
+function initNetMonitor(url, window, enableCache) {
   info("Initializing a network monitor pane.");
 
   return Task.spawn(function* () {
-    let tab = yield addTab(aUrl);
-    info("Net tab added successfully: " + aUrl);
+    let tab = yield addTab(url);
+    info("Net tab added successfully: " + url);
 
     let target = TargetFactory.forTab(tab);
 
     yield target.makeRemote();
     info("Target remoted.");
 
-    if (!aEnableCache) {
+    if (!enableCache) {
       info("Disabling cache and reloading page.");
       yield toggleCache(target, true);
       info("Cache disabled when the current and all future toolboxes are open.");
@@ -175,9 +180,9 @@ function teardown(monitor) {
   });
 }
 
-function waitForNetworkEvents(aMonitor, aGetRequests, aPostRequests = 0) {
+function waitForNetworkEvents(monitor, getRequests, postRequests = 0) {
   let deferred = promise.defer();
-  let panel = aMonitor.panelWin;
+  let panel = monitor.panelWin;
   let progress = {};
   let genericEvents = 0;
   let postEvents = 0;
@@ -200,9 +205,13 @@ function waitForNetworkEvents(aMonitor, aGetRequests, aPostRequests = 0) {
   ];
 
   function initProgressForURL(url) {
-    if (progress[url]) return;
+    if (progress[url]) {
+      return;
+    }
     progress[url] = {};
-    awaitedEventsToListeners.forEach(([e]) => progress[url][e] = 0);
+    awaitedEventsToListeners.forEach(function ([e]) {
+      progress[url][e] = 0;
+    });
   }
 
   function updateProgressForURL(url, event) {
@@ -222,8 +231,8 @@ function waitForNetworkEvents(aMonitor, aGetRequests, aPostRequests = 0) {
 
   function maybeResolve(event, actor) {
     info("> Network events progress: " +
-      genericEvents + "/" + ((aGetRequests + aPostRequests) * 13) + ", " +
-      postEvents + "/" + (aPostRequests * 2) + ", " +
+      genericEvents + "/" + ((getRequests + postRequests) * 13) + ", " +
+      postEvents + "/" + (postRequests * 2) + ", " +
       "got " + event + " for " + actor);
 
     let networkInfo =
@@ -237,9 +246,8 @@ function waitForNetworkEvents(aMonitor, aGetRequests, aPostRequests = 0) {
     // There are 15 updates which need to be fired for a request to be
     // considered finished. The "requestPostData" packet isn't fired for
     // non-POST requests.
-    if (genericEvents >= (aGetRequests + aPostRequests) * 13 &&
-        postEvents >= aPostRequests * 2) {
-
+    if (genericEvents >= (getRequests + postRequests) * 13 &&
+        postEvents >= postRequests * 2) {
       awaitedEventsToListeners.forEach(([e, l]) => panel.off(EVENTS[e], l));
       executeSoon(deferred.resolve);
     }
@@ -249,39 +257,40 @@ function waitForNetworkEvents(aMonitor, aGetRequests, aPostRequests = 0) {
   return deferred.promise;
 }
 
-function verifyRequestItemTarget(document, requestList, requestItem, aMethod,
-                                 aUrl, aData = {}) {
-  info("> Verifying: " + aMethod + " " + aUrl + " " + aData.toSource());
+function verifyRequestItemTarget(document, requestList, requestItem, method,
+                                 url, data = {}) {
+  info("> Verifying: " + method + " " + url + " " + data.toSource());
 
   let visibleIndex = requestList.indexOf(requestItem);
 
   info("Visible index of item: " + visibleIndex);
 
   let { fuzzyUrl, status, statusText, cause, type, fullMimeType,
-        transferred, size, time, displayedStatus } = aData;
+        transferred, size, time, displayedStatus } = data;
 
   let target = document.querySelectorAll(".request-list-item")[visibleIndex];
-  let unicodeUrl = decodeUnicodeUrl(aUrl);
-  let name = getUrlBaseName(aUrl);
-  let query = getUrlQuery(aUrl);
-  let hostPort = getUrlHost(aUrl);
+  let unicodeUrl = decodeUnicodeUrl(url);
+  let name = getUrlBaseName(url);
+  let query = getUrlQuery(url);
+  let hostPort = getUrlHost(url);
   let remoteAddress = requestItem.remoteAddress;
 
   if (fuzzyUrl) {
-    ok(requestItem.method.startsWith(aMethod), "The attached method is correct.");
-    ok(requestItem.url.startsWith(aUrl), "The attached url is correct.");
+    ok(requestItem.method.startsWith(method), "The attached method is correct.");
+    ok(requestItem.url.startsWith(url), "The attached url is correct.");
   } else {
-    is(requestItem.method, aMethod, "The attached method is correct.");
-    is(requestItem.url, aUrl, "The attached url is correct.");
+    is(requestItem.method, method, "The attached method is correct.");
+    is(requestItem.url, url, "The attached url is correct.");
   }
 
   is(target.querySelector(".requests-list-method").textContent,
-    aMethod, "The displayed method is correct.");
+    method, "The displayed method is correct.");
 
   if (fuzzyUrl) {
     ok(target.querySelector(".requests-list-file").textContent.startsWith(
       name + (query ? "?" + query : "")), "The displayed file is correct.");
-    ok(target.querySelector(".requests-list-file").getAttribute("title").startsWith(unicodeUrl),
+    ok(target.querySelector(".requests-list-file").getAttribute("title")
+                                                  .startsWith(unicodeUrl),
       "The tooltip file is correct.");
   } else {
     is(target.querySelector(".requests-list-file").textContent,
@@ -298,13 +307,15 @@ function verifyRequestItemTarget(document, requestList, requestItem, aMethod,
     domainTooltip, "The tooltip domain is correct.");
 
   if (status !== undefined) {
-    let value = target.querySelector(".requests-list-status-icon").getAttribute("data-code");
+    let value = target.querySelector(".requests-list-status-icon")
+                      .getAttribute("data-code");
     let codeValue = target.querySelector(".requests-list-status-code").textContent;
     let tooltip = target.querySelector(".requests-list-status").getAttribute("title");
     info("Displayed status: " + value);
     info("Displayed code: " + codeValue);
     info("Tooltip status: " + tooltip);
-    is(value, displayedStatus ? displayedStatus : status, "The displayed status is correct.");
+    is(value, displayedStatus ? displayedStatus : status,
+      "The displayed status is correct.");
     is(codeValue, status, "The displayed status code is correct.");
     is(tooltip, status + " " + statusText, "The tooltip status is correct.");
   }
@@ -314,7 +325,7 @@ function verifyRequestItemTarget(document, requestList, requestItem, aMethod,
     info("Displayed cause: " + value);
     info("Tooltip cause: " + tooltip);
     is(value, cause.type, "The displayed cause is correct.");
-    is(tooltip, cause.loadingDocumentUri, "The tooltip cause is correct.")
+    is(tooltip, cause.loadingDocumentUri, "The tooltip cause is correct.");
   }
   if (type !== undefined) {
     let value = target.querySelector(".requests-list-type").textContent;
@@ -326,7 +337,8 @@ function verifyRequestItemTarget(document, requestList, requestItem, aMethod,
   }
   if (transferred !== undefined) {
     let value = target.querySelector(".requests-list-transferred").textContent;
-    let tooltip = target.querySelector(".requests-list-transferred").getAttribute("title");
+    let tooltip = target.querySelector(".requests-list-transferred")
+                        .getAttribute("title");
     info("Displayed transferred size: " + value);
     info("Tooltip transferred size: " + tooltip);
     is(value, transferred, "The displayed transferred size is correct.");
@@ -342,7 +354,8 @@ function verifyRequestItemTarget(document, requestList, requestItem, aMethod,
   }
   if (time !== undefined) {
     let value = target.querySelector(".requests-list-timings-total").textContent;
-    let tooltip = target.querySelector(".requests-list-timings-total").getAttribute("title");
+    let tooltip = target.querySelector(".requests-list-timings-total")
+                        .getAttribute("title");
     info("Displayed time: " + value);
     info("Tooltip time: " + tooltip);
     ok(~~(value.match(/[0-9]+/)) >= 0, "The displayed time is correct.");
@@ -403,12 +416,12 @@ function testFilterButtons(monitor, filterType) {
  *        'checked' attribute. For example, if the third item of the array
  *        evaluates to true, the third button should be checked.
  */
-function testFilterButtonsCustom(aMonitor, aIsChecked) {
-  let doc = aMonitor.panelWin.document;
+function testFilterButtonsCustom(monitor, isChecked) {
+  let doc = monitor.panelWin.document;
   let buttons = doc.querySelectorAll("#requests-list-filter-buttons button");
-  for (let i = 0; i < aIsChecked.length; i++) {
+  for (let i = 0; i < isChecked.length; i++) {
     let button = buttons[i];
-    if (aIsChecked[i]) {
+    if (isChecked[i]) {
       is(button.classList.contains("checked"), true,
         "The " + button.id + " button should have a 'checked' class.");
       is(button.getAttribute("aria-pressed"), "true",
@@ -473,9 +486,8 @@ function executeInContent(name, data = {}, objects = {}, expectResponse = true)
   mm.sendAsyncMessage(name, data, objects);
   if (expectResponse) {
     return waitForContentMessage(name);
-  } else {
-    return promise.resolve();
   }
+  return promise.resolve();
 }
 
 /**
diff --git a/devtools/client/netmonitor/test/html_api-calls-test-page.html b/devtools/client/netmonitor/test/html_api-calls-test-page.html
index e3187231936b..8c0263c45082 100644
--- a/devtools/client/netmonitor/test/html_api-calls-test-page.html
+++ b/devtools/client/netmonitor/test/html_api-calls-test-page.html
@@ -15,30 +15,35 @@
     <p>API calls request test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send();
       }
 
       function performRequests() {
-        get("/api/fileName.xml", function() {
-          get("/api/file%E2%98%A2.xml", function() {
-            get("/api/ascii/get/", function() {
-              get("/api/unicode/%E2%98%A2/", function() {
-                get("/api/search/?q=search%E2%98%A2", function() {
+        /* eslint-disable max-nested-callbacks */
+        get("/api/fileName.xml", function () {
+          get("/api/file%E2%98%A2.xml", function () {
+            get("/api/ascii/get/", function () {
+              get("/api/unicode/%E2%98%A2/", function () {
+                get("/api/search/?q=search%E2%98%A2", function () {
                   // Done.
                 });
               });
             });
           });
         });
+        /* eslint-enable max-nested-callbacks */
       }
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_brotli-test-page.html b/devtools/client/netmonitor/test/html_brotli-test-page.html
index d5afae4b3159..508bb4318f19 100644
--- a/devtools/client/netmonitor/test/html_brotli-test-page.html
+++ b/devtools/client/netmonitor/test/html_brotli-test-page.html
@@ -15,20 +15,23 @@
     <p>Brotli test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=br", function() {
+        get("sjs_content-type-test-server.sjs?fmt=br", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_cause-test-page.html b/devtools/client/netmonitor/test/html_cause-test-page.html
index d2b86682bfda..9e83fe45d75d 100644
--- a/devtools/client/netmonitor/test/html_cause-test-page.html
+++ b/devtools/client/netmonitor/test/html_cause-test-page.html
@@ -16,8 +16,10 @@
     <p>Request cause test</p>
     <img src="img_request" />
     <script type="text/javascript">
+      "use strict";
+
       function performXhrRequest() {
-        var xhr = new XMLHttpRequest();
+        let xhr = new XMLHttpRequest();
         xhr.open("GET", "xhr_request", true);
         xhr.send();
       }
diff --git a/devtools/client/netmonitor/test/html_content-type-test-page.html b/devtools/client/netmonitor/test/html_content-type-test-page.html
index 23ecf1f442d0..33ee8f84c53e 100644
--- a/devtools/client/netmonitor/test/html_content-type-test-page.html
+++ b/devtools/client/netmonitor/test/html_content-type-test-page.html
@@ -15,25 +15,29 @@
     <p>Content type test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=xml", function() {
-          get("sjs_content-type-test-server.sjs?fmt=css", function() {
-            get("sjs_content-type-test-server.sjs?fmt=js", function() {
-              get("sjs_content-type-test-server.sjs?fmt=json", function() {
-                get("sjs_content-type-test-server.sjs?fmt=bogus", function() {
-                  get("test-image.png", function() {
+        /* eslint-disable max-nested-callbacks */
+        get("sjs_content-type-test-server.sjs?fmt=xml", function () {
+          get("sjs_content-type-test-server.sjs?fmt=css", function () {
+            get("sjs_content-type-test-server.sjs?fmt=js", function () {
+              get("sjs_content-type-test-server.sjs?fmt=json", function () {
+                get("sjs_content-type-test-server.sjs?fmt=bogus", function () {
+                  get("test-image.png", function () {
                     // Done.
                   });
                 });
@@ -41,6 +45,7 @@
             });
           });
         });
+        /* eslint-enable max-nested-callbacks */
       }
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_content-type-without-cache-test-page.html b/devtools/client/netmonitor/test/html_content-type-without-cache-test-page.html
index f27e6e105994..c30359573054 100644
--- a/devtools/client/netmonitor/test/html_content-type-without-cache-test-page.html
+++ b/devtools/client/netmonitor/test/html_content-type-without-cache-test-page.html
@@ -15,27 +15,31 @@
     <p>Content type test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=xml", function() {
-          get("sjs_content-type-test-server.sjs?fmt=css", function() {
-            get("sjs_content-type-test-server.sjs?fmt=js", function() {
-              get("sjs_content-type-test-server.sjs?fmt=json", function() {
-                get("sjs_content-type-test-server.sjs?fmt=bogus", function() {
-                  get("test-image.png?v=" + Math.random(), function() {
-                    get("sjs_content-type-test-server.sjs?fmt=gzip", function() {
-                      get("sjs_content-type-test-server.sjs?fmt=br", function() {
+        /* eslint-disable max-nested-callbacks */
+        get("sjs_content-type-test-server.sjs?fmt=xml", function () {
+          get("sjs_content-type-test-server.sjs?fmt=css", function () {
+            get("sjs_content-type-test-server.sjs?fmt=js", function () {
+              get("sjs_content-type-test-server.sjs?fmt=json", function () {
+                get("sjs_content-type-test-server.sjs?fmt=bogus", function () {
+                  get("test-image.png?v=" + Math.random(), function () {
+                    get("sjs_content-type-test-server.sjs?fmt=gzip", function () {
+                      get("sjs_content-type-test-server.sjs?fmt=br", function () {
                         // Done.
                       });
                     });
@@ -45,6 +49,7 @@
             });
           });
         });
+        /* eslint-enable max-nested-callbacks */
       }
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_copy-as-curl.html b/devtools/client/netmonitor/test/html_copy-as-curl.html
index 3ddcfbcedb66..e30d0a8aede9 100644
--- a/devtools/client/netmonitor/test/html_copy-as-curl.html
+++ b/devtools/client/netmonitor/test/html_copy-as-curl.html
@@ -15,9 +15,12 @@
     <p>Performing a GET request</p>
 
     <script type="text/javascript">
-      function performRequest(aUrl) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aUrl, true);
+      /* exported performRequest */
+      "use strict";
+
+      function performRequest(url) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", url, true);
         xhr.setRequestHeader("Accept-Language", window.navigator.language);
         xhr.setRequestHeader("X-Custom-Header-1", "Custom value");
         xhr.setRequestHeader("X-Custom-Header-2", "8.8.8.8");
diff --git a/devtools/client/netmonitor/test/html_cors-test-page.html b/devtools/client/netmonitor/test/html_cors-test-page.html
index 179b2ed00516..3eda9af3d101 100644
--- a/devtools/client/netmonitor/test/html_cors-test-page.html
+++ b/devtools/client/netmonitor/test/html_cors-test-page.html
@@ -15,8 +15,11 @@
     <p>POST with CORS test page</p>
 
     <script type="text/javascript">
+      /* exported performRequests */
+      "use strict";
+
       function post(url, contentType, postData) {
-        var xhr = new XMLHttpRequest();
+        let xhr = new XMLHttpRequest();
         xhr.open("POST", url, true);
         xhr.setRequestHeader("Content-Type", contentType);
         xhr.send(postData);
diff --git a/devtools/client/netmonitor/test/html_curl-utils.html b/devtools/client/netmonitor/test/html_curl-utils.html
index 8ff7ecdf0da1..16a5e89e0e4a 100644
--- a/devtools/client/netmonitor/test/html_curl-utils.html
+++ b/devtools/client/netmonitor/test/html_curl-utils.html
@@ -29,39 +29,41 @@
     <iframe name="target"></iframe>
 
     <script type="text/javascript">
+      /* exported performRequests */
+      "use strict";
 
-      function ajaxGet(aUrl, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aUrl + "?param1=value1&param2=value2&param3=value3", true);
+      function ajaxGet(url, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", url + "?param1=value1&param2=value2&param3=value3", true);
         xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
-        xhr.onload = function() {
-          aCallback();
+        xhr.onload = function () {
+          callback();
         };
         xhr.send();
       }
 
-      function ajaxPost(aUrl, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aUrl, true);
+      function ajaxPost(url, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", url, true);
         xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
         xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
-        xhr.onload = function() {
-          aCallback();
+        xhr.onload = function () {
+          callback();
         };
-        var params = "param1=value1&param2=value2&param3=value3";
+        const params = "param1=value1&param2=value2&param3=value3";
         xhr.send(params);
       }
 
-      function ajaxMultipart(aUrl, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aUrl, true);
+      function ajaxMultipart(url, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", url, true);
         xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
-        xhr.onload = function() {
-          aCallback();
+        xhr.onload = function () {
+          callback();
         };
 
         getCanvasElem().toBlob((blob) => {
-          var formData = new FormData();
+          let formData = new FormData();
           formData.append("param1", "value1");
           formData.append("file", blob, "filename.png");
           xhr.send(formData);
@@ -69,7 +71,7 @@
       }
 
       function submitForm() {
-        var form = document.querySelector("#post-form");
+        let form = document.querySelector("#post-form");
         form.submit();
       }
 
@@ -78,17 +80,17 @@
       }
 
       function initCanvas() {
-        var canvas = getCanvasElem();
-        var ctx = canvas.getContext("2d");
-        ctx.fillRect(0,0,100,100);
-        ctx.clearRect(20,20,60,60);
-        ctx.strokeRect(25,25,50,50);
+        let canvas = getCanvasElem();
+        let ctx = canvas.getContext("2d");
+        ctx.fillRect(0, 0, 100, 100);
+        ctx.clearRect(20, 20, 60, 60);
+        ctx.strokeRect(25, 25, 50, 50);
       }
 
-      function performRequests(aUrl) {
-        ajaxGet(aUrl, () => {
-          ajaxPost(aUrl, () => {
-            ajaxMultipart(aUrl, () => {
+      function performRequests(url) {
+        ajaxGet(url, () => {
+          ajaxPost(url, () => {
+            ajaxMultipart(url, () => {
               submitForm();
             });
           });
diff --git a/devtools/client/netmonitor/test/html_custom-get-page.html b/devtools/client/netmonitor/test/html_custom-get-page.html
index 19e40f93a3b2..2a2b59bdb2d4 100644
--- a/devtools/client/netmonitor/test/html_custom-get-page.html
+++ b/devtools/client/netmonitor/test/html_custom-get-page.html
@@ -15,27 +15,30 @@
     <p>Performing a custom number of GETs</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       // Use a count parameter to defeat caching.
-      var count = 0;
+      let count = 0;
 
-      function performRequests(aTotal, aUrl, aTimeout = 0) {
-        if (!aTotal) {
+      function performRequests(total, url, timeout = 0) {
+        if (!total) {
           return;
         }
-        get(aUrl || "request_" + (count++), function() {
-          setTimeout(performRequests.bind(this, --aTotal, aUrl, aTimeout), aTimeout);
+        get(url || "request_" + (count++), function () {
+          setTimeout(performRequests.bind(this, --total, url, timeout), timeout);
         });
       }
     </script>
diff --git a/devtools/client/netmonitor/test/html_cyrillic-test-page.html b/devtools/client/netmonitor/test/html_cyrillic-test-page.html
index 8735ac674f62..d89b92f8d42d 100644
--- a/devtools/client/netmonitor/test/html_cyrillic-test-page.html
+++ b/devtools/client/netmonitor/test/html_cyrillic-test-page.html
@@ -16,20 +16,23 @@
     <p>Братан, ты вообще качаешься?</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=txt", function() {
+        get("sjs_content-type-test-server.sjs?fmt=txt", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_filter-test-page.html b/devtools/client/netmonitor/test/html_filter-test-page.html
index eb5d02ed9b9f..48ce26d6f03a 100644
--- a/devtools/client/netmonitor/test/html_filter-test-page.html
+++ b/devtools/client/netmonitor/test/html_filter-test-page.html
@@ -15,44 +15,52 @@
     <p>Filtering test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        // Use a random parameter to defeat caching.
-        xhr.open("GET", aAddress + "&" + Math.random(), true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        // Use a random parameter to defeat caching.
+        xhr.open("GET", address + "&" + Math.random(), true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
-      function performRequests(aOptions) {
-        var options = JSON.parse(aOptions);
-        get("sjs_content-type-test-server.sjs?fmt=html&res=" + options.htmlContent, function() {
-          get("sjs_content-type-test-server.sjs?fmt=css", function() {
-            get("sjs_content-type-test-server.sjs?fmt=js", function() {
-              if (!options.getMedia) {
-                return;
-              }
-              get("sjs_content-type-test-server.sjs?fmt=font", function() {
-                get("sjs_content-type-test-server.sjs?fmt=image", function() {
-                  get("sjs_content-type-test-server.sjs?fmt=audio", function() {
-                    get("sjs_content-type-test-server.sjs?fmt=video", function() {
-                      if (!options.getFlash) {
-                        return;
-                      }
-                      get("sjs_content-type-test-server.sjs?fmt=flash", function() {
-                        // Done.
+      function performRequests(optionsText) {
+        const options = JSON.parse(optionsText);
+
+        /* eslint-disable max-nested-callbacks */
+        get("sjs_content-type-test-server.sjs?fmt=html&res=" + options.htmlContent,
+            function () {
+              get("sjs_content-type-test-server.sjs?fmt=css", function () {
+                get("sjs_content-type-test-server.sjs?fmt=js", function () {
+                  if (!options.getMedia) {
+                    return;
+                  }
+                  get("sjs_content-type-test-server.sjs?fmt=font", function () {
+                    get("sjs_content-type-test-server.sjs?fmt=image", function () {
+                      get("sjs_content-type-test-server.sjs?fmt=audio", function () {
+                        get("sjs_content-type-test-server.sjs?fmt=video", function () {
+                          if (!options.getFlash) {
+                            return;
+                          }
+                          get("sjs_content-type-test-server.sjs?fmt=flash", function () {
+                            // Done.
+                          });
+                        });
                       });
                     });
                   });
                 });
               });
-            });
-          });
-        });
+            }
+        );
+        /* eslint-enable max-nested-callbacks */
       }
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_frame-subdocument.html b/devtools/client/netmonitor/test/html_frame-subdocument.html
index 9e800582c577..3ed424ed727b 100644
--- a/devtools/client/netmonitor/test/html_frame-subdocument.html
+++ b/devtools/client/netmonitor/test/html_frame-subdocument.html
@@ -16,8 +16,10 @@
     <p>Request frame test</p>
     <img src="img_request" />
     <script type="text/javascript">
+      "use strict";
+
       function performXhrRequest() {
-        var xhr = new XMLHttpRequest();
+        let xhr = new XMLHttpRequest();
         xhr.open("GET", "xhr_request", true);
         xhr.send();
       }
diff --git a/devtools/client/netmonitor/test/html_frame-test-page.html b/devtools/client/netmonitor/test/html_frame-test-page.html
index 66f6620af23e..f28a7ef03915 100644
--- a/devtools/client/netmonitor/test/html_frame-test-page.html
+++ b/devtools/client/netmonitor/test/html_frame-test-page.html
@@ -17,8 +17,10 @@
     <img src="img_request" />
     <iframe src="html_frame-subdocument.html"></iframe>
     <script type="text/javascript">
+      "use strict";
+
       function performXhrRequest() {
-        var xhr = new XMLHttpRequest();
+        let xhr = new XMLHttpRequest();
         xhr.open("GET", "xhr_request", true);
         xhr.send();
       }
diff --git a/devtools/client/netmonitor/test/html_image-tooltip-test-page.html b/devtools/client/netmonitor/test/html_image-tooltip-test-page.html
index c39db909e6cb..68956aeff48e 100644
--- a/devtools/client/netmonitor/test/html_image-tooltip-test-page.html
+++ b/devtools/client/netmonitor/test/html_image-tooltip-test-page.html
@@ -15,8 +15,11 @@
     <p>tooltip test</p>
 
     <script type="text/javascript">
+      /* exported performRequests */
+      "use strict";
+
       function performRequests() {
-        var xhr = new XMLHttpRequest();
+        let xhr = new XMLHttpRequest();
         xhr.open("GET", "test-image.png?v=" + Math.random(), true);
         xhr.send(null);
       }
diff --git a/devtools/client/netmonitor/test/html_infinite-get-page.html b/devtools/client/netmonitor/test/html_infinite-get-page.html
index f51b718adc9d..03bf1e821ad5 100644
--- a/devtools/client/netmonitor/test/html_infinite-get-page.html
+++ b/devtools/client/netmonitor/test/html_infinite-get-page.html
@@ -15,23 +15,25 @@
     <p>Infinite GETs</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       // Use a count parameter to defeat caching.
-      var count = 0;
+      let count = 0;
 
       (function performRequests() {
-        get("request_" + (count++), function() {
+        get("request_" + (count++), function () {
           setTimeout(performRequests, 50);
         });
       })();
diff --git a/devtools/client/netmonitor/test/html_json-b64.html b/devtools/client/netmonitor/test/html_json-b64.html
index 6871f9d90d1c..53aae262b1fa 100644
--- a/devtools/client/netmonitor/test/html_json-b64.html
+++ b/devtools/client/netmonitor/test/html_json-b64.html
@@ -15,20 +15,23 @@
     <p>JSON b64 test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=json-b64", function() {
+        get("sjs_content-type-test-server.sjs?fmt=json-b64", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_json-basic.html b/devtools/client/netmonitor/test/html_json-basic.html
index edd480f33fa7..4f565b54377f 100644
--- a/devtools/client/netmonitor/test/html_json-basic.html
+++ b/devtools/client/netmonitor/test/html_json-basic.html
@@ -16,13 +16,16 @@
     <p>Pass the JSON name (as supported by sjs_json-test-server.sjs) as a query parameter</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
@@ -30,7 +33,7 @@
 
       function performRequests() {
         // Forward the query parameter for this page to sjs_json-test-server
-        get("sjs_json-test-server.sjs" + window.location.search, function() {
+        get("sjs_json-test-server.sjs" + window.location.search, function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_json-custom-mime-test-page.html b/devtools/client/netmonitor/test/html_json-custom-mime-test-page.html
index 646fc60ea89a..9273e43a37ae 100644
--- a/devtools/client/netmonitor/test/html_json-custom-mime-test-page.html
+++ b/devtools/client/netmonitor/test/html_json-custom-mime-test-page.html
@@ -15,20 +15,23 @@
     <p>JSONP test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=json-custom-mime", function() {
+        get("sjs_content-type-test-server.sjs?fmt=json-custom-mime", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_json-long-test-page.html b/devtools/client/netmonitor/test/html_json-long-test-page.html
index b538b4c27876..82cd3b37c2c2 100644
--- a/devtools/client/netmonitor/test/html_json-long-test-page.html
+++ b/devtools/client/netmonitor/test/html_json-long-test-page.html
@@ -15,20 +15,23 @@
     <p>JSON long string test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=json-long", function() {
+        get("sjs_content-type-test-server.sjs?fmt=json-long", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_json-malformed-test-page.html b/devtools/client/netmonitor/test/html_json-malformed-test-page.html
index 0c8627ab5aac..b29a3e645dd0 100644
--- a/devtools/client/netmonitor/test/html_json-malformed-test-page.html
+++ b/devtools/client/netmonitor/test/html_json-malformed-test-page.html
@@ -15,20 +15,23 @@
     <p>JSON malformed test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=json-malformed", function() {
+        get("sjs_content-type-test-server.sjs?fmt=json-malformed", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_json-text-mime-test-page.html b/devtools/client/netmonitor/test/html_json-text-mime-test-page.html
index 2c64e253156e..07e2c0cc1626 100644
--- a/devtools/client/netmonitor/test/html_json-text-mime-test-page.html
+++ b/devtools/client/netmonitor/test/html_json-text-mime-test-page.html
@@ -15,20 +15,23 @@
     <p>JSON text test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=json-text-mime", function() {
+        get("sjs_content-type-test-server.sjs?fmt=json-text-mime", function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_jsonp-test-page.html b/devtools/client/netmonitor/test/html_jsonp-test-page.html
index 78c0da08be13..a1c9ad17747e 100644
--- a/devtools/client/netmonitor/test/html_jsonp-test-page.html
+++ b/devtools/client/netmonitor/test/html_jsonp-test-page.html
@@ -15,21 +15,24 @@
     <p>JSONP test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_content-type-test-server.sjs?fmt=jsonp&jsonp=$_0123Fun", function() {
-          get("sjs_content-type-test-server.sjs?fmt=jsonp2&jsonp=$_4567Sad", function() {
+        get("sjs_content-type-test-server.sjs?fmt=jsonp&jsonp=$_0123Fun", function () {
+          get("sjs_content-type-test-server.sjs?fmt=jsonp2&jsonp=$_4567Sad", function () {
             // Done.
           });
         });
diff --git a/devtools/client/netmonitor/test/html_params-test-page.html b/devtools/client/netmonitor/test/html_params-test-page.html
index 3f30e3d7616b..e29b013cb9ef 100644
--- a/devtools/client/netmonitor/test/html_params-test-page.html
+++ b/devtools/client/netmonitor/test/html_params-test-page.html
@@ -15,41 +15,45 @@
     <p>Request params type test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aQuery) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress + aQuery, true);
+      /* exported performRequests */
+      "use strict";
+
+      function get(address, query) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address + query, true);
         xhr.send();
       }
 
-      function post(aAddress, aQuery, aContentType, aPostBody) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress + aQuery, true);
-        xhr.setRequestHeader("content-type", aContentType);
-        xhr.send(aPostBody);
+      function post(address, query, contentType, postBody) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address + query, true);
+        xhr.setRequestHeader("content-type", contentType);
+        xhr.send(postBody);
       }
 
       function performRequests() {
-        var urlencoded = "application/x-www-form-urlencoded";
+        const urlencoded = "application/x-www-form-urlencoded";
 
-        setTimeout(function() {
+        /* eslint-disable max-nested-callbacks */
+        setTimeout(function () {
           post("baz", "?a", urlencoded, '{ "foo": "bar" }');
 
-          setTimeout(function() {
+          setTimeout(function () {
             post("baz", "?a=b", urlencoded, '{ "foo": "bar" }');
 
-            setTimeout(function() {
-              post("baz", "?a=b", urlencoded, '?foo=bar');
+            setTimeout(function () {
+              post("baz", "?a=b", urlencoded, "?foo=bar");
 
-              setTimeout(function() {
+              setTimeout(function () {
                 post("baz", "?a", undefined, '{ "foo": "bar" }');
 
-                setTimeout(function() {
+                setTimeout(function () {
                   post("baz", "?a=b", undefined, '{ "foo": "bar" }');
 
-                  setTimeout(function() {
-                    post("baz", "?a=b", undefined, '?foo=bar');
+                  setTimeout(function () {
+                    post("baz", "?a=b", undefined, "?foo=bar");
 
-                    setTimeout(function() {
+                    setTimeout(function () {
                       get("baz", "");
 
                       // Done.
@@ -60,6 +64,7 @@
             }, 10);
           }, 10);
         }, 10);
+        /* eslint-enable max-nested-callbacks */
       }
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_post-data-test-page.html b/devtools/client/netmonitor/test/html_post-data-test-page.html
index 8dedc7b606cf..8bf830f3ce9c 100644
--- a/devtools/client/netmonitor/test/html_post-data-test-page.html
+++ b/devtools/client/netmonitor/test/html_post-data-test-page.html
@@ -27,46 +27,49 @@
     </form>
 
     <script type="text/javascript">
-      function post(aAddress, aMessage, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress, true);
+      /* exported performRequests */
+      "use strict";
+
+      function post(address, message, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address, true);
         xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
 
-        var data = "";
-        for (var i in aMessage) {
-          data += "&" + i + "=" + aMessage[i];
+        let data = "";
+        for (let i in message) {
+          data += "&" + i + "=" + message[i];
         }
 
-        xhr.onreadystatechange = function() {
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(data);
       }
 
-      function form(aAddress, aForm, aCallback) {
-        var formData = new FormData(document.forms.namedItem(aForm));
+      function form(address, formName, callback) {
+        let formData = new FormData(document.forms.namedItem(formName));
         formData.append("Custom field", "Extra data");
 
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress, true);
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address, true);
 
-        xhr.onreadystatechange = function() {
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(formData);
       }
 
       function performRequests() {
-        var url = "sjs_simple-test-server.sjs";
-        var url1 = url + "?foo=bar&baz=42&type=urlencoded";
-        var url2 = url + "?foo=bar&baz=42&type=multipart";
+        const url = "sjs_simple-test-server.sjs";
+        const url1 = url + "?foo=bar&baz=42&type=urlencoded";
+        const url2 = url + "?foo=bar&baz=42&type=multipart";
 
-        post(url1, { foo: "bar", baz: 123 }, function() {
-          form(url2, "form-name", function() {
+        post(url1, { foo: "bar", baz: 123 }, function () {
+          form(url2, "form-name", function () {
             // Done.
           });
         });
diff --git a/devtools/client/netmonitor/test/html_post-json-test-page.html b/devtools/client/netmonitor/test/html_post-json-test-page.html
index 129feaf08b8e..3338abc39c62 100644
--- a/devtools/client/netmonitor/test/html_post-json-test-page.html
+++ b/devtools/client/netmonitor/test/html_post-json-test-page.html
@@ -15,6 +15,9 @@
     <p>POST raw test</p>
 
     <script type="text/javascript">
+      /* exported performRequests */
+      "use strict";
+
       function post(address, message, callback) {
         let xhr = new XMLHttpRequest();
         xhr.open("POST", address, true);
diff --git a/devtools/client/netmonitor/test/html_post-raw-test-page.html b/devtools/client/netmonitor/test/html_post-raw-test-page.html
index b4456348c3b8..4656c438ac8e 100644
--- a/devtools/client/netmonitor/test/html_post-raw-test-page.html
+++ b/devtools/client/netmonitor/test/html_post-raw-test-page.html
@@ -15,22 +15,25 @@
     <p>POST raw test</p>
 
     <script type="text/javascript">
-      function post(aAddress, aMessage, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress, true);
+      /* exported performRequests */
+      "use strict";
+
+      function post(address, message, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address, true);
         xhr.setRequestHeader("content-type", "application/x-www-form-urlencoded");
 
-        xhr.onreadystatechange = function() {
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
-        xhr.send(aMessage);
+        xhr.send(message);
       }
 
       function performRequests() {
-        var rawData = "foo=bar&baz=123";
-        post("sjs_simple-test-server.sjs", rawData, function() {
+        const rawData = "foo=bar&baz=123";
+        post("sjs_simple-test-server.sjs", rawData, function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_post-raw-with-headers-test-page.html b/devtools/client/netmonitor/test/html_post-raw-with-headers-test-page.html
index 3bb8f9071eb3..7859d14241ca 100644
--- a/devtools/client/netmonitor/test/html_post-raw-with-headers-test-page.html
+++ b/devtools/client/netmonitor/test/html_post-raw-with-headers-test-page.html
@@ -15,27 +15,30 @@
     <p>POST raw with headers test</p>
 
     <script type="text/javascript">
-      function post(aAddress, aMessage, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("POST", aAddress, true);
+      /* exported performRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function post(address, message, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("POST", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
-        xhr.send(aMessage);
+        xhr.send(message);
       }
 
       function performRequests() {
-        var rawData = [
+        let rawData = [
           "content-type: application/x-www-form-urlencoded\r",
           "custom-header: hello world!\r",
           "\r",
           "\r",
           "foo=bar&baz=123"
         ];
-        post("sjs_simple-test-server.sjs", rawData.join("\n"), function() {
+        post("sjs_simple-test-server.sjs", rawData.join("\n"), function () {
           // Done.
         });
       }
diff --git a/devtools/client/netmonitor/test/html_send-beacon.html b/devtools/client/netmonitor/test/html_send-beacon.html
index 95cc005bd4db..6efb9fb4369c 100644
--- a/devtools/client/netmonitor/test/html_send-beacon.html
+++ b/devtools/client/netmonitor/test/html_send-beacon.html
@@ -15,6 +15,9 @@
     <p>Send beacon test</p>
 
     <script type="text/javascript">
+    /* exported performRequest */
+    "use strict";
+
     function performRequest() {
       navigator.sendBeacon("beacon_request");
     }
diff --git a/devtools/client/netmonitor/test/html_single-get-page.html b/devtools/client/netmonitor/test/html_single-get-page.html
index 0055d4ee051e..252b24854332 100644
--- a/devtools/client/netmonitor/test/html_single-get-page.html
+++ b/devtools/client/netmonitor/test/html_single-get-page.html
@@ -15,20 +15,22 @@
     <p>Performing a custom number of GETs</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       (function performRequests() {
-        get("request_0", function() {});
+        get("request_0", function () {});
       })();
     </script>
   </body>
diff --git a/devtools/client/netmonitor/test/html_statistics-test-page.html b/devtools/client/netmonitor/test/html_statistics-test-page.html
index b4b15b82bf2f..0621293f4e85 100644
--- a/devtools/client/netmonitor/test/html_statistics-test-page.html
+++ b/devtools/client/netmonitor/test/html_statistics-test-page.html
@@ -15,9 +15,11 @@
     <p>Statistics test</p>
 
     <script type="text/javascript">
-      function get(aAddress) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      "use strict";
+
+      function get(address) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
         xhr.send(null);
       }
 
diff --git a/devtools/client/netmonitor/test/html_status-codes-test-page.html b/devtools/client/netmonitor/test/html_status-codes-test-page.html
index 4be779bd4e01..fc8f762bc6a9 100644
--- a/devtools/client/netmonitor/test/html_status-codes-test-page.html
+++ b/devtools/client/netmonitor/test/html_status-codes-test-page.html
@@ -15,35 +15,40 @@
     <p>Status codes test</p>
 
     <script type="text/javascript">
-      function get(aAddress, aCallback) {
-        var xhr = new XMLHttpRequest();
-        xhr.open("GET", aAddress, true);
+      /* exported performRequests, performCachedRequests */
+      "use strict";
 
-        xhr.onreadystatechange = function() {
+      function get(address, callback) {
+        let xhr = new XMLHttpRequest();
+        xhr.open("GET", address, true);
+
+        xhr.onreadystatechange = function () {
           if (this.readyState == this.DONE) {
-            aCallback();
+            callback();
           }
         };
         xhr.send(null);
       }
 
       function performRequests() {
-        get("sjs_status-codes-test-server.sjs?sts=100", function() {
-          get("sjs_status-codes-test-server.sjs?sts=200", function() {
-            get("sjs_status-codes-test-server.sjs?sts=300", function() {
-              get("sjs_status-codes-test-server.sjs?sts=400", function() {
-                get("sjs_status-codes-test-server.sjs?sts=500", function() {
+        /* eslint-disable max-nested-callbacks */
+        get("sjs_status-codes-test-server.sjs?sts=100", function () {
+          get("sjs_status-codes-test-server.sjs?sts=200", function () {
+            get("sjs_status-codes-test-server.sjs?sts=300", function () {
+              get("sjs_status-codes-test-server.sjs?sts=400", function () {
+                get("sjs_status-codes-test-server.sjs?sts=500", function () {
                   // Done.
                 });
               });
             });
           });
         });
+        /* eslint-enable max-nested-callbacks */
       }
 
       function performCachedRequests() {
-        get("sjs_status-codes-test-server.sjs?sts=ok&cached", function() {
-          get("sjs_status-codes-test-server.sjs?sts=redirect&cached", function() {
+        get("sjs_status-codes-test-server.sjs?sts=ok&cached", function () {
+          get("sjs_status-codes-test-server.sjs?sts=redirect&cached", function () {
             // Done.
           });
         });
diff --git a/devtools/client/netmonitor/test/require-helper.js b/devtools/client/netmonitor/test/require-helper.js
index 349506d6c2fa..04529a07abff 100644
--- a/devtools/client/netmonitor/test/require-helper.js
+++ b/devtools/client/netmonitor/test/require-helper.js
@@ -31,4 +31,6 @@ requireHacker.global_hook("default", path => {
     case "devtools/client/shared/redux/create-store":
       return `module.exports = require("devtools/client/netmonitor/test/fixtures/create-store")`;
   }
+
+  return null;
 });
diff --git a/devtools/client/netmonitor/test/service-workers/status-codes.html b/devtools/client/netmonitor/test/service-workers/status-codes.html
index 975535dc627b..69579d77c813 100644
--- a/devtools/client/netmonitor/test/service-workers/status-codes.html
+++ b/devtools/client/netmonitor/test/service-workers/status-codes.html
@@ -16,6 +16,9 @@
     <p>Status codes test</p>
 
     <script type="text/javascript">
+      /* exported registerServiceWorker, unregisterServiceWorker, performRequests */
+      "use strict";
+
       let swRegistration;
 
       function registerServiceWorker() {
@@ -31,7 +34,7 @@
               if (sw.controller) {
                 resolve();
               } else {
-                sw.addEventListener('controllerchange', function () {
+                sw.addEventListener("controllerchange", function () {
                   resolve();
                 }, {once: true});
               }