firefox/devtools/startup/tests/xpcshell/test_devtools_shim.js

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

"use strict";

const { DevToolsShim } = ChromeUtils.importESModule(
  "chrome://devtools-startup/content/DevToolsShim.sys.mjs"
);

// Test the DevToolsShim

/**
 * Create a mocked version of DevTools that records all calls made to methods expected
 * to be called by DevToolsShim.
 */
function createMockDevTools() {
  const methods = [
    "on",
    "off",
    "emit",
    "saveDevToolsSession",
    "restoreDevToolsSession",
  ];

  const mock = {
    callLog: {},
  };

  for (const method of methods) {
    // Create a stub for method, that only pushes its arguments in the inner callLog
    mock[method] = function (...args) {
      mock.callLog[method].push(args);
    };
    mock.callLog[method] = [];
  }

  return mock;
}

/**
 * Check if a given method was called an expected number of times, and finally check the
 * arguments provided to the last call, if appropriate.
 */
function checkCalls(mock, method, length, lastArgs) {
  Assert.strictEqual(
    mock.callLog[method].length,
    length,
    "Devtools.on was called the expected number of times"
  );

  // If we don't want to check the last call or if the method was never called, bail out.
  if (!lastArgs || length === 0) {
    return;
  }

  for (let i = 0; i < lastArgs.length; i++) {
    const expectedArg = lastArgs[i];
    Assert.strictEqual(
      mock.callLog[method][length - 1][i],
      expectedArg,
      `Devtools.${method} was called with the expected argument (index ${i})`
    );
  }
}

function test_register_unregister() {
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  DevToolsShim.register(createMockDevTools());
  ok(DevToolsShim.isInitialized(), "DevTools are initialized");

  DevToolsShim.unregister();
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");
}

function test_on_is_forwarded_to_devtools() {
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  function cb1() {}
  function cb2() {}
  const mock = createMockDevTools();

  DevToolsShim.on("test_event", cb1);
  DevToolsShim.register(mock);
  checkCalls(mock, "on", 1, ["test_event", cb1]);

  DevToolsShim.on("other_event", cb2);
  checkCalls(mock, "on", 2, ["other_event", cb2]);
}

function test_off_called_before_registering_devtools() {
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  function cb1() {}
  const mock = createMockDevTools();

  DevToolsShim.on("test_event", cb1);
  DevToolsShim.off("test_event", cb1);

  DevToolsShim.register(mock);
  checkCalls(mock, "on", 0);
}

function test_off_called_before_with_bad_callback() {
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  function cb1() {}
  function cb2() {}
  const mock = createMockDevTools();

  DevToolsShim.on("test_event", cb1);
  DevToolsShim.off("test_event", cb2);

  DevToolsShim.register(mock);
  // on should still be called
  checkCalls(mock, "on", 1, ["test_event", cb1]);
  // Calls to off should not be held and forwarded.
  checkCalls(mock, "off", 0);
}

function test_events() {
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  const mock = createMockDevTools();
  // Check emit was not called.
  checkCalls(mock, "emit", 0);

  // Check emit is called once with the devtools-registered event.
  DevToolsShim.register(mock);
  checkCalls(mock, "emit", 1, ["devtools-registered"]);

  // Check emit is called once with the devtools-unregistered event.
  DevToolsShim.unregister();
  checkCalls(mock, "emit", 2, ["devtools-unregistered"]);
}

function test_restore_session_apis() {
  // Backup method that will be updated for the test.
  const initDevToolsBackup = DevToolsShim.initDevTools;

  // Create fake session objects to restore.
  const sessionWithoutDevTools = {};
  const sessionWithDevTools = {
    browserConsole: true,
  };

  Services.prefs.setBoolPref("devtools.policy.disabled", true);
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");
  ok(!DevToolsShim.isEnabled(), "DevTools are not enabled");

  // Check that save & restore DevToolsSession don't initialize the tools and don't
  // crash.
  DevToolsShim.saveDevToolsSession({});
  DevToolsShim.restoreDevToolsSession(sessionWithDevTools);
  ok(!DevToolsShim.isInitialized(), "DevTools are still not initialized");

  Services.prefs.setBoolPref("devtools.policy.disabled", false);
  ok(DevToolsShim.isEnabled(), "DevTools are enabled");
  ok(!DevToolsShim.isInitialized(), "DevTools are not initialized");

  // Check that DevTools are not initialized when calling restoreDevToolsSession without
  // DevTools related data.
  DevToolsShim.restoreDevToolsSession(sessionWithoutDevTools);
  ok(!DevToolsShim.isInitialized(), "DevTools are still not initialized");

  const mock = createMockDevTools();
  DevToolsShim.initDevTools = () => {
    // Next call to restoreDevToolsSession is expected to initialize DevTools, which we
    // simulate here by registering our mock.
    DevToolsShim.register(mock);
  };

  DevToolsShim.restoreDevToolsSession(sessionWithDevTools);
  checkCalls(mock, "restoreDevToolsSession", 1, [sessionWithDevTools]);

  ok(DevToolsShim.isInitialized(), "DevTools are initialized");

  DevToolsShim.saveDevToolsSession({});
  checkCalls(mock, "saveDevToolsSession", 1, []);

  // Restore initDevTools backup.
  DevToolsShim.initDevTools = initDevToolsBackup;
}

function run_test() {
  test_register_unregister();
  DevToolsShim.unregister();

  test_on_is_forwarded_to_devtools();
  DevToolsShim.unregister();

  test_off_called_before_registering_devtools();
  DevToolsShim.unregister();

  test_off_called_before_with_bad_callback();
  DevToolsShim.unregister();

  test_restore_session_apis();
  DevToolsShim.unregister();

  test_events();
}