fune/testing/modules/tests/xpcshell/test_mockRegistrar.js

/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

const { MockRegistrar } = ChromeUtils.import(
  "resource://testing-common/MockRegistrar.jsm"
);

function platformInfo(injectedValue) {
  this.platformVersion = injectedValue;
}

platformInfo.prototype = {
  platformVersion: "some version",
  platformBuildID: "some id",
  QueryInterface: ChromeUtils.generateQI([Ci.nsIPlatformInfo]),
};

add_test(function test_register() {
  let localPlatformInfo = {
    platformVersion: "local version",
    platformBuildID: "local id",
    QueryInterface: ChromeUtils.generateQI([Ci.nsIPlatformInfo]),
  };

  MockRegistrar.register("@mozilla.org/xre/app-info;1", localPlatformInfo);
  Assert.equal(
    Cc["@mozilla.org/xre/app-info;1"].createInstance(Ci.nsIPlatformInfo)
      .platformVersion,
    "local version"
  );
  run_next_test();
});

add_test(function test_register_with_arguments() {
  MockRegistrar.register("@mozilla.org/xre/app-info;1", platformInfo, [
    "override",
  ]);
  Assert.equal(
    Cc["@mozilla.org/xre/app-info;1"].createInstance(Ci.nsIPlatformInfo)
      .platformVersion,
    "override"
  );
  run_next_test();
});

add_test(function test_register_twice() {
  MockRegistrar.register("@mozilla.org/xre/app-info;1", platformInfo, [
    "override",
  ]);
  Assert.equal(
    Cc["@mozilla.org/xre/app-info;1"].createInstance(Ci.nsIPlatformInfo)
      .platformVersion,
    "override"
  );

  MockRegistrar.register("@mozilla.org/xre/app-info;1", platformInfo, [
    "override again",
  ]);
  Assert.equal(
    Cc["@mozilla.org/xre/app-info;1"].createInstance(Ci.nsIPlatformInfo)
      .platformVersion,
    "override again"
  );
  run_next_test();
});