diff --git a/.eslintignore b/.eslintignore
index a4ee00f84f6f..90ac6d438b10 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -182,7 +182,6 @@ dom/cache/test/mochitest/**
 dom/cache/test/xpcshell/**
 dom/canvas/**
 dom/console/**
-dom/crypto/**
 dom/encoding/**
 dom/events/**
 dom/fetch/**
diff --git a/dom/crypto/test/test-array.js b/dom/crypto/test/test-array.js
index 5dbe6bea50ae..54a616ef188a 100644
--- a/dom/crypto/test/test-array.js
+++ b/dom/crypto/test/test-array.js
@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// This file expects utils.js to be included in its scope
+/* import-globals-from ./util.js */
 var MOCHITEST = false;
 
 function Test(name, test) {
@@ -34,7 +36,9 @@ function Test(name, test) {
   };
 
   this.complete = function(result) {
-    if (MOCHITEST) { ok(result, this.name); }
+    if (MOCHITEST) {
+      ok(result, this.name);
+    }
 
     // Note the end time
     this.endTime = new Date();
@@ -60,28 +64,30 @@ function Test(name, test) {
 
     // Print the name of the test
     if (this.name) {
-      this.row[0].innerHTML = this.name;
+      this.row[0].textContent = this.name;
       var that = this;
-      this.row[0].onclick = function() { that.run(); };
+      this.row[0].onclick = function() {
+        that.run();
+      };
     } else {
       this.row[0] = "";
     }
 
     // Print the result of the test
-    if (this.result == true) {
+    if (this.result === true) {
       this.row[1].className = "pass";
       this.row[1].innerHTML = "PASS";
-    } else if (this.result == false) {
+    } else if (this.result === false) {
       this.row[1].className = "fail";
       this.row[1].innerHTML = "FAIL";
     } else {
       // this.row[1].innerHTML = "";
-      this.row[1].innerHTML = this.result;
+      this.row[1].textContent = this.result;
     }
 
     // Print the elapsed time, if known
     if (this.startTime && this.endTime) {
-      this.row[2].innerHTML = (this.endTime - this.startTime) + " ms";
+      this.row[2].textContent = (this.endTime - this.startTime) + " ms";
     } else {
       this.row[2].innerHTML = "";
     }
@@ -143,13 +149,13 @@ var TestArray = {
   updateSummary() {
     this.pass = this.fail = this.pending = 0;
     for (var i = 0; i < this.tests.length; ++i) {
-      if (this.tests[i].result == true) this.pass++;
-      if (this.tests[i].result == false) this.fail++;
+      if (this.tests[i].result === true) this.pass++;
+      if (this.tests[i].result === false) this.fail++;
       if (this.tests[i].result == null) this.pending++;
     }
-    this.passSpan.innerHTML = this.pass;
-    this.failSpan.innerHTML = this.fail;
-    this.pendingSpan.innerHTML = this.pending;
+    this.passSpan.textContent = this.pass;
+    this.failSpan.textContent = this.fail;
+    this.pendingSpan.textContent = this.pending;
   },
 
   load() {
@@ -182,7 +188,9 @@ var TestArray = {
     this.updateSummary();
     var i = this.currTest++;
     if (i >= this.tests.length) {
-      if (MOCHITEST) { SimpleTest.finish(); }
+      if (MOCHITEST) {
+        SimpleTest.finish();
+      }
       return;
     }
 
@@ -195,16 +203,20 @@ var TestArray = {
 };
 
 if (window.addEventListener) {
-  window.addEventListener("load", function() { TestArray.load(); } );
+  window.addEventListener("load", function() {
+    TestArray.load();
+  });
 } else {
-  window.attachEvent("onload", function() { TestArray.load(); } );
+  window.attachEvent("onload", function() {
+    TestArray.load();
+  });
 }
 
 function start() {
   TestArray.run();
 }
 
-MOCHITEST = ("SimpleTest" in window);
+MOCHITEST = "SimpleTest" in window;
 if (MOCHITEST) {
   SimpleTest.waitForExplicitFinish();
   SimpleTest.requestLongerTimeout(2);
diff --git a/dom/crypto/test/test-vectors.js b/dom/crypto/test/test-vectors.js
index ac4187e8490a..aebefdf84db8 100644
--- a/dom/crypto/test/test-vectors.js
+++ b/dom/crypto/test/test-vectors.js
@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-tv = {
+// This file expects utils.js to be included in its scope
+/* import-globals-from ./util.js */
+let tv = {
   raw: util.hex2abv("f3095c4fe5e299477643c2310b44f0aa"),
 
   // this key had an inappropriate length (18 octets)
diff --git a/dom/crypto/test/test-worker.js b/dom/crypto/test/test-worker.js
index 65edf0329a68..5b52ddf84511 100644
--- a/dom/crypto/test/test-worker.js
+++ b/dom/crypto/test/test-worker.js
@@ -2,6 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/* eslint-env worker */
+
+// This file expects utils.js to be included in its scope
+/* import-globals-from ./util.js */
 importScripts("util.js");
 importScripts("test-vectors.js");
 
@@ -34,6 +38,7 @@ function error(test) {
 }
 
 onmessage = function(msg) {
+  // eslint-disable-next-line no-eval
   var test = eval("(" + msg.data + ")");
 
   try {
diff --git a/dom/crypto/test/test_WebCrypto.html b/dom/crypto/test/test_WebCrypto.html
index 7d95ee6796f6..d3cbb1243cd2 100644
--- a/dom/crypto/test/test_WebCrypto.html
+++ b/dom/crypto/test/test_WebCrypto.html
@@ -26,7 +26,6 @@
 TestArray.addTest(
   "Test for presence of WebCrypto API methods",
   function() {
-    var that = this;
     this.complete(
       exists(window.crypto.subtle) &&
       exists(window.crypto.subtle.encrypt) &&
@@ -630,11 +629,6 @@ TestArray.addTest(
         x, tv.aes_ctr_dec.data);
     }
 
-    function decrypt(x) {
-      return decrypt(x, new Uint8Array(15))
-        .catch(function() { return decrypt(x, new Uint8Array(17)); });
-    }
-
     crypto.subtle.importKey("raw", tv.aes_ctr_dec.key, "AES-CTR", false, ["decrypt"])
       .then(doDecrypt)
       .then(
@@ -1004,7 +998,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "RSASSA-PKCS1-v1_5", hash: "SHA-256" };
-    var use = ["sign", "verify"];
 
     function doVerify(x) {
       return crypto.subtle.verify(alg.name, x, tv.rsassa.sig_fail, tv.rsassa.data);
@@ -1103,7 +1096,7 @@ TestArray.addTest(
       error(that)();
     }
 
-    Promise.all([p1, p2, p3]).then(complete(that, keys => {
+    return Promise.all([p1, p2, p3]).then(complete(that, keys => {
       return keys.every(key => {
         if (key instanceof CryptoKey) {
           return checkPrototypes(key, "CryptoKey");
diff --git a/dom/crypto/test/test_WebCrypto_DH.html b/dom/crypto/test/test_WebCrypto_DH.html
index d6bc48710c04..09924c78b30a 100644
--- a/dom/crypto/test/test_WebCrypto_DH.html
+++ b/dom/crypto/test/test_WebCrypto_DH.html
@@ -21,7 +21,6 @@
 
 <script>/* <![CDATA[*/
 "use strict";
-
 // -----------------------------------------------------------------------------
 TestArray.addTest(
   "Generate a DH key",
@@ -68,11 +67,7 @@ TestArray.addTest(
     };
 
     function doDerive(x) {
-      var alg = {
-        name: "DH",
-        public: x.publicKey,
-      };
-      return crypto.subtle.deriveBits(alg, x.privateKey, 128);
+      return crypto.subtle.deriveBits({ name: "DH", public: x.publicKey }, x.privateKey, 128);
     }
 
     crypto.subtle.generateKey(alg, false, ["deriveBits"])
@@ -218,8 +213,7 @@ TestArray.addTest(
     }
 
     function doDerive(pubKey) {
-      var alg = {name: "DH", public: pubKey};
-      return crypto.subtle.deriveBits(alg, privKey, 128);
+      return crypto.subtle.deriveBits({name: "DH", public: pubKey}, privKey, 128);
     }
 
     crypto.subtle.generateKey(alg, false, ["deriveBits"])
diff --git a/dom/crypto/test/test_WebCrypto_ECDH.html b/dom/crypto/test/test_WebCrypto_ECDH.html
index 32fe28f27e52..34c68b3996d0 100644
--- a/dom/crypto/test/test_WebCrypto_ECDH.html
+++ b/dom/crypto/test/test_WebCrypto_ECDH.html
@@ -62,8 +62,7 @@ TestArray.addTest(
 
     function doDerive(n) {
       return function(x) {
-        var alg = { name: "ECDH", public: pair.publicKey };
-        return crypto.subtle.deriveBits(alg, pair.privateKey, n * 8);
+        return crypto.subtle.deriveBits({ name: "ECDH", public: pair.publicKey }, pair.privateKey, n * 8);
       };
     }
 
@@ -165,8 +164,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveBits(alg, privKey, tv.ecdh_p256.secret.byteLength * 8);
+      return crypto.subtle.deriveBits({ name: "ECDH", public: pubKey }, privKey, tv.ecdh_p256.secret.byteLength * 8);
     }
 
     Promise.all([
@@ -191,8 +189,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveBits(alg, privKey, tv.ecdh_p384.secret.byteLength * 8);
+      return crypto.subtle.deriveBits({ name: "ECDH", public: pubKey }, privKey, tv.ecdh_p384.secret.byteLength * 8);
     }
 
     Promise.all([
@@ -217,8 +214,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveBits(alg, privKey, tv.ecdh_p521.secret.byteLength * 8);
+      return crypto.subtle.deriveBits({ name: "ECDH", public: pubKey }, privKey, tv.ecdh_p521.secret.byteLength * 8);
     }
 
     Promise.all([
@@ -342,8 +338,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveKey(alg, privKey, algDerived, false, ["sign", "verify"])
+      return crypto.subtle.deriveKey({ name: "ECDH", public: pubKey }, privKey, algDerived, false, ["sign", "verify"])
         .then(function(x) {
           if (!hasKeyFields(x)) {
             throw "Invalid key; missing field(s)";
@@ -406,6 +401,7 @@ TestArray.addTest(
         if (keys.length) {
           return nextKey();
         }
+        return Promise.resolve();
       });
     }
 
@@ -425,8 +421,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveBits(alg, privKey, tv.ecdh_p256.secret.byteLength * 8);
+      return crypto.subtle.deriveBits({ name: "ECDH", public: pubKey }, privKey, tv.ecdh_p256.secret.byteLength * 8);
     }
 
     Promise.all([
@@ -462,7 +457,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "ECDH", namedCurve: "P-256" };
-    var tvs = tv.ecdh_p256_negative.raw_bad;
 
     crypto.subtle.importKey("raw", tv, alg, false, ["deriveBits"])
       .then(error(that), complete(that));
@@ -475,7 +469,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "ECDH", namedCurve: "P-256" };
-    var tvs = tv.ecdh_p256.raw;
 
     crypto.subtle.importKey("unknown", tv, alg, false, ["deriveBits"])
       .then(error(that), complete(that));
@@ -488,7 +481,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "ECDH", namedCurve: "P-256" };
-    var tvs = tv.ecdh_p256_negative.raw_short;
 
     crypto.subtle.importKey("raw", tv, alg, false, ["deriveBits"])
       .then(error(that), complete(that));
@@ -501,7 +493,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "ECDH", namedCurve: "P-256" };
-    var tvs = tv.ecdh_p256_negative.raw_long;
 
     crypto.subtle.importKey("raw", tv, alg, false, ["deriveBits"])
       .then(error(that), complete(that));
@@ -514,7 +505,6 @@ TestArray.addTest(
   function() {
     var that = this;
     var alg = { name: "ECDH", namedCurve: "P-256" };
-    var tvs = tv.ecdh_p256_negative.raw_compressed;
 
     crypto.subtle.importKey("raw", tv, alg, false, ["deriveBits"])
       .then(error(that), complete(that));
@@ -533,8 +523,7 @@ TestArray.addTest(
     function setPriv(x) { privKey = x; }
 
     function doDerive() {
-      var alg = { name: "ECDH", public: pubKey };
-      return crypto.subtle.deriveBits(alg, privKey, tv.ecdh_p256.secret.byteLength * 8);
+      return crypto.subtle.deriveBits({ name: "ECDH", public: pubKey }, privKey, tv.ecdh_p256.secret.byteLength * 8);
     }
 
     Promise.all([
diff --git a/dom/crypto/test/test_WebCrypto_ECDSA.html b/dom/crypto/test/test_WebCrypto_ECDSA.html
index f4ff95bcf400..bc02b1d2e9e2 100644
--- a/dom/crypto/test/test_WebCrypto_ECDSA.html
+++ b/dom/crypto/test/test_WebCrypto_ECDSA.html
@@ -135,10 +135,6 @@ TestArray.addTest(
     var that = this;
     var alg = { name: "ECDSA", namedCurve: "P-256", hash: "SHA-256" };
 
-    function doVerify(x) {
-      return crypto.subtle.verify(alg, x, tv.ecdsa_verify.sig, tv.ecdsa_verify.data);
-    }
-
     crypto.subtle.importKey("jwk", tv.ecdsa_bad.pub_jwk, alg, true, ["verify"])
       .then(error(that), complete(that));
   }
diff --git a/dom/crypto/test/test_WebCrypto_HKDF.html b/dom/crypto/test/test_WebCrypto_HKDF.html
index e9ae9a4b37ba..62a078cec0c7 100644
--- a/dom/crypto/test/test_WebCrypto_HKDF.html
+++ b/dom/crypto/test/test_WebCrypto_HKDF.html
@@ -146,23 +146,27 @@ TestArray.addTest(
   function() {
     var that = this;
     var tests = tv.hkdf.slice();
+    if (!tests.length) {
+      error(that)("No tests found");
+      return;
+    }
 
     function next() {
       if (!tests.length) {
-        return;
+        return Promise.resolve();
       }
 
       var test = tests.shift();
-      var {key, data} = test;
+      var {key} = test;
 
       return crypto.subtle.importKey("raw", key, "HKDF", false, ["deriveBits"])
-        .then(function(key) {
+        .then(function(baseKey) {
           return crypto.subtle.deriveBits({
             name: "HKDF",
             hash: test.prf,
             salt: test.salt,
             info: test.info,
-          }, key, test.data.byteLength * 8);
+          }, baseKey, test.data.byteLength * 8);
         })
         .then(function(data) {
           if (!util.memcmp(data, test.data)) {
diff --git a/dom/crypto/test/test_WebCrypto_Normalize.html b/dom/crypto/test/test_WebCrypto_Normalize.html
index eb5c7d071311..c586d1194e9a 100644
--- a/dom/crypto/test/test_WebCrypto_Normalize.html
+++ b/dom/crypto/test/test_WebCrypto_Normalize.html
@@ -29,23 +29,21 @@ TestArray.addTest(
     var alg = { name: "hmac", hash: {name: "sHa-256"} };
 
     function doGenerateAesKey() {
-      var alg = { name: "AES-gcm", length: 192 };
-      return crypto.subtle.generateKey(alg, false, ["encrypt"]);
+      return crypto.subtle.generateKey({ name: "AES-gcm", length: 192 }, false, ["encrypt"]);
     }
 
     function doGenerateRsaOaepKey() {
-      var alg = {
+      var algo = {
         name: "rsa-OAEP",
         hash: "sha-1",
         modulusLength: 2048,
         publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
       };
-      return crypto.subtle.generateKey(alg, false, ["encrypt", "decrypt"]);
+      return crypto.subtle.generateKey(algo, false, ["encrypt", "decrypt"]);
     }
 
     function doGenerateRsaSsaPkcs1Key() {
-      var alg = { name: "RSASSA-pkcs1-V1_5", hash: "SHA-1" };
-      return crypto.subtle.importKey("pkcs8", tv.pkcs8, alg, true, ["sign"]);
+      return crypto.subtle.importKey("pkcs8", tv.pkcs8, { name: "RSASSA-pkcs1-V1_5", hash: "SHA-1" }, true, ["sign"]);
     }
 
     crypto.subtle.generateKey(alg, false, ["sign"])
diff --git a/dom/crypto/test/test_WebCrypto_PBKDF2.html b/dom/crypto/test/test_WebCrypto_PBKDF2.html
index 6e7823d82691..229f6049326e 100644
--- a/dom/crypto/test/test_WebCrypto_PBKDF2.html
+++ b/dom/crypto/test/test_WebCrypto_PBKDF2.html
@@ -76,13 +76,13 @@ TestArray.addTest(
         throw "Invalid key; missing field(s)";
       }
 
-      var alg = {
+      var algo = {
         name: "PBKDF2",
         hash: "SHA-1",
         salt: tv.pbkdf2_sha1.salt,
         iterations: tv.pbkdf2_sha1.iterations,
       };
-      return crypto.subtle.deriveBits(alg, x, tv.pbkdf2_sha1.length);
+      return crypto.subtle.deriveBits(algo, x, tv.pbkdf2_sha1.length);
     }
     function fail(x) { console.log("failing"); error(that)(x); }
 
@@ -104,13 +104,13 @@ TestArray.addTest(
         throw "Invalid key; missing field(s)";
       }
 
-      var alg = {
+      var algo = {
         name: "PBKDF2",
         hash: "SHA-1",
         salt: tv.pbkdf2_sha1.salt,
         iterations: tv.pbkdf2_sha1.iterations,
       };
-      return crypto.subtle.deriveBits(alg, x, tv.pbkdf2_sha1.length);
+      return crypto.subtle.deriveBits(algo, x, tv.pbkdf2_sha1.length);
     }
     function fail(x) { console.log("failing"); error(that)(x); }
 
@@ -133,7 +133,7 @@ TestArray.addTest(
         throw "Invalid key; missing field(s)";
       }
 
-      var alg = {
+      var algo = {
         name: "PBKDF2",
         hash: "SHA-1",
         salt: tv.pbkdf2_sha1.salt,
@@ -145,17 +145,17 @@ TestArray.addTest(
         hash: {name: "SHA-1"},
       };
 
-      return crypto.subtle.deriveKey(alg, x, algDerived, false, ["sign", "verify"])
-        .then(function(x) {
-          if (!hasKeyFields(x)) {
+      return crypto.subtle.deriveKey(algo, x, algDerived, false, ["sign", "verify"])
+        .then(function(y) {
+          if (!hasKeyFields(y)) {
             throw "Invalid key; missing field(s)";
           }
 
-          if (x.algorithm.length != 512) {
+          if (y.algorithm.length != 512) {
             throw "Invalid key; incorrect length";
           }
 
-          return x;
+          return y;
         });
     }
 
@@ -217,13 +217,13 @@ TestArray.addTest(
         throw "Invalid key; missing field(s)";
       }
 
-      var alg = {
+      var algo = {
         name: "PBKDF2",
         hash: "SHA-256",
         salt: tv.pbkdf2_sha256.salt,
         iterations: tv.pbkdf2_sha256.iterations,
       };
-      return crypto.subtle.deriveBits(alg, x, tv.pbkdf2_sha256.length);
+      return crypto.subtle.deriveBits(algo, x, tv.pbkdf2_sha256.length);
     }
     function fail(x) { console.log("failing"); error(that)(x); }
 
@@ -246,13 +246,13 @@ TestArray.addTest(
         throw "Invalid key; missing field(s)";
       }
 
-      var alg = {
+      var algo = {
         name: "PBKDF2",
         hash: "SHA-256",
         salt: tv.pbkdf2_sha256_no_pwd.salt,
         iterations: tv.pbkdf2_sha256_no_pwd.iterations,
       };
-      return crypto.subtle.deriveBits(alg, x, tv.pbkdf2_sha256_no_pwd.length);
+      return crypto.subtle.deriveBits(algo, x, tv.pbkdf2_sha256_no_pwd.length);
     }
     function fail(x) { console.log("failing"); error(that)(x); }
 
diff --git a/dom/crypto/test/test_WebCrypto_RSA_OAEP.html b/dom/crypto/test/test_WebCrypto_RSA_OAEP.html
index e54694ac69b0..aaa12cc95ad9 100644
--- a/dom/crypto/test/test_WebCrypto_RSA_OAEP.html
+++ b/dom/crypto/test/test_WebCrypto_RSA_OAEP.html
@@ -33,7 +33,6 @@ TestArray.addTest(
     var privKey, pubKey;
     var alg = {name: "RSA-OAEP", hash: "SHA-1"};
 
-    var privKey, pubKey;
     function setPriv(x) { privKey = x; }
     function setPub(x) { pubKey = x; }
     function doEncrypt() {
@@ -112,7 +111,7 @@ TestArray.addTest(
   "RSA-OAEP input data length checks (2048-bit key)",
   function() {
     var that = this;
-    var privKey, pubKey;
+    var pubKey;
     var alg = {
       name: "RSA-OAEP",
       hash: "SHA-1",
@@ -120,8 +119,7 @@ TestArray.addTest(
       publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
     };
 
-    var privKey, pubKey;
-    function setKey(x) { pubKey = x.publicKey; privKey = x.privateKey; }
+    function setKey(x) { pubKey = x.publicKey; }
     function doEncrypt(n) {
       console.log("entered encrypt(" + n + ")");
       return function() {
diff --git a/dom/crypto/test/test_WebCrypto_RSA_PSS.html b/dom/crypto/test/test_WebCrypto_RSA_PSS.html
index 7cce4fd1add5..e0df5ecde8f0 100644
--- a/dom/crypto/test/test_WebCrypto_RSA_PSS.html
+++ b/dom/crypto/test/test_WebCrypto_RSA_PSS.html
@@ -58,12 +58,10 @@ TestArray.addTest(
     var data = crypto.getRandomValues(new Uint8Array(128));
     function setKey(x) { pubKey = x.publicKey; privKey = x.privateKey; }
     function doSign() {
-      var alg = {name: "RSA-PSS", saltLength: 32};
-      return crypto.subtle.sign(alg, privKey, data);
+      return crypto.subtle.sign({name: "RSA-PSS", saltLength: 32}, privKey, data);
     }
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: 32};
-      return crypto.subtle.verify(alg, pubKey, x, data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: 32}, pubKey, x, data);
     }
 
     crypto.subtle.generateKey(alg, false, ["sign", "verify"])
@@ -83,8 +81,7 @@ TestArray.addTest(
     var vec = tv.rsapss;
 
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: vec.saltLength};
-      return crypto.subtle.verify(alg, x, vec.sig, vec.data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: vec.saltLength}, x, vec.sig, vec.data);
     }
 
     crypto.subtle.importKey("spki", vec.spki, alg, false, ["verify"])
@@ -102,17 +99,17 @@ TestArray.addTest(
     var vec = tv.rsapss;
 
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: vec.saltLength};
+      var algo = {name: "RSA-PSS", saltLength: vec.saltLength};
       var clone1 = new Uint8Array(vec.data);
       var clone2 = new Uint8Array(vec.data);
       clone1[clone1.byteLength - 1] ^= 1;
       clone2[0] ^= 1;
 
       return Promise.all([
-        crypto.subtle.verify(alg, x, vec.sig, clone1),
-        crypto.subtle.verify(alg, x, vec.sig, clone2),
-        crypto.subtle.verify(alg, x, vec.sig, vec.data.slice(1)),
-        crypto.subtle.verify(alg, x, vec.sig, vec.data.slice(0, vec.data.byteLength - 1)),
+        crypto.subtle.verify(algo, x, vec.sig, clone1),
+        crypto.subtle.verify(algo, x, vec.sig, clone2),
+        crypto.subtle.verify(algo, x, vec.sig, vec.data.slice(1)),
+        crypto.subtle.verify(algo, x, vec.sig, vec.data.slice(0, vec.data.byteLength - 1)),
       ]);
     }
 
@@ -131,8 +128,7 @@ TestArray.addTest(
     var alg = {name: "RSA-PSS", hash: "SHA-1"};
 
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: tv.rsapss.saltLength};
-      return crypto.subtle.verify(alg, x, tv.rsapss.sig, tv.rsapss.data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: tv.rsapss.saltLength}, x, tv.rsapss.sig, tv.rsapss.data);
     }
 
     crypto.subtle.importKey("jwk", tv.rsapss.jwk_pub, alg, false, ["verify"])
@@ -172,12 +168,10 @@ TestArray.addTest(
     var privKey, pubKey;
     function setKeys([pub, priv]) { pubKey = pub; privKey = priv; }
     function doSign() {
-      var alg = {name: "RSA-PSS", saltLength: tv.rsapss.saltLength};
-      return crypto.subtle.sign(alg, privKey, tv.rsapss.data);
+      return crypto.subtle.sign({name: "RSA-PSS", saltLength: tv.rsapss.saltLength}, privKey, tv.rsapss.data);
     }
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: tv.rsapss.saltLength};
-      return crypto.subtle.verify(alg, pubKey, x, tv.rsapss.data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: tv.rsapss.saltLength}, pubKey, x, tv.rsapss.data);
     }
 
     var spki =
@@ -203,12 +197,10 @@ TestArray.addTest(
     var privKey, pubKey;
     function setKeys([pub, priv]) { pubKey = pub; privKey = priv; }
     function doSign() {
-      var alg = {name: "RSA-PSS", saltLength: tv.rsapss.saltLength};
-      return crypto.subtle.sign(alg, privKey, tv.rsapss.data);
+      return crypto.subtle.sign({name: "RSA-PSS", saltLength: tv.rsapss.saltLength}, privKey, tv.rsapss.data);
     }
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: tv.rsapss.saltLength};
-      return crypto.subtle.verify(alg, pubKey, x, tv.rsapss.data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: tv.rsapss.saltLength}, pubKey, x, tv.rsapss.data);
     }
 
     var spki =
@@ -341,16 +333,14 @@ TestArray.addTest(
     function setKey(x) { pubKey = x.publicKey; privKey = x.privateKey; }
 
     function doSignTwice() {
-      var alg = {name: "RSA-PSS", saltLength: 0};
       return Promise.all([
-        crypto.subtle.sign(alg, privKey, data),
-        crypto.subtle.sign(alg, privKey, data),
+        crypto.subtle.sign({name: "RSA-PSS", saltLength: 0}, privKey, data),
+        crypto.subtle.sign({name: "RSA-PSS", saltLength: 0}, privKey, data),
       ]);
     }
 
     function doVerify(x) {
-      var alg = {name: "RSA-PSS", saltLength: 0};
-      return crypto.subtle.verify(alg, pubKey, x, data);
+      return crypto.subtle.verify({name: "RSA-PSS", saltLength: 0}, pubKey, x, data);
     }
 
     crypto.subtle.generateKey(alg, false, ["sign", "verify"])
diff --git a/dom/crypto/test/test_WebCrypto_Workers.html b/dom/crypto/test/test_WebCrypto_Workers.html
index 15368495f035..66412f5c88b5 100644
--- a/dom/crypto/test/test_WebCrypto_Workers.html
+++ b/dom/crypto/test/test_WebCrypto_Workers.html
@@ -42,8 +42,7 @@ TestArray.addTest(
     crypto.subtle.generateKey(alg, false, ["encrypt", "decrypt"]).then(key => {
       // Wait for ciphertext, check and decrypt.
       worker.addEventListener("message", ({data: ciphertext}) => {
-        var alg = { name: "AES-GCM", iv: nonce };
-        crypto.subtle.decrypt(alg, key, ciphertext)
+        crypto.subtle.decrypt({ name: "AES-GCM", iv: nonce }, key, ciphertext)
           .then(memcmp_complete(that, data), error(that));
       });
 
diff --git a/dom/crypto/test/test_WebCrypto_Wrap_Unwrap.html b/dom/crypto/test/test_WebCrypto_Wrap_Unwrap.html
index 7897347fc227..02c61d433bf6 100644
--- a/dom/crypto/test/test_WebCrypto_Wrap_Unwrap.html
+++ b/dom/crypto/test/test_WebCrypto_Wrap_Unwrap.html
@@ -98,7 +98,7 @@ TestArray.addTest(
       iv: tv.key_wrap_known_answer.wrapping_iv,
       tagLength: 128,
     };
-    var key, wrappingKey;
+    var wrappingKey;
 
     function doUnwrap(k) {
       wrappingKey = k;
diff --git a/dom/crypto/test/test_indexedDB.html b/dom/crypto/test/test_indexedDB.html
index 951b03b05f61..1f8bb0453589 100644
--- a/dom/crypto/test/test_indexedDB.html
+++ b/dom/crypto/test/test_indexedDB.html
@@ -39,9 +39,9 @@
         frame.remove();
 
         // Load the test app again to retrieve stored keys.
-        createMozBrowserFrame((frame, result) => {
-          is(result, "ok", "retrieved keys successfully");
-          frame.remove();
+        createMozBrowserFrame((recFrame, recResult) => {
+          is(recResult, "ok", "retrieved keys successfully");
+          recFrame.remove();
           SimpleTest.finish();
         });
       });
diff --git a/dom/crypto/test/util.js b/dom/crypto/test/util.js
index 7a3b473c0bde..02edc91ccde2 100644
--- a/dom/crypto/test/util.js
+++ b/dom/crypto/test/util.js
@@ -105,7 +105,7 @@ function shallowArrayEquals(x, y) {
     return false;
   }
 
-  for (i in x) {
+  for (let i in x) {
     if (x[i] != y[i]) {
       return false;
     }