1 files changed, 203 insertions, 0 deletions
diff --git a/devtools/shared/loader/builtin-modules.js b/devtools/shared/loader/builtin-modules.js
new file mode 100644
index 0000000000..7dc04e5e98
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+++ b/devtools/shared/loader/builtin-modules.js
@@ -0,0 +1,203 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+"use strict";
+
+/**
+ * This module defines custom globals injected in all our modules and also
+ * pseudo modules that aren't separate files but just dynamically set values.
+ *
+ * Note that some globals are being defined by base-loader.sys.mjs via wantGlobalProperties property.
+ *
+ * As it does so, the module itself doesn't have access to these globals,
+ * nor the pseudo modules. Be careful to avoid loading any other js module as
+ * they would also miss them.
+ */
+
+const systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+
+/**
+ * Defines a getter on a specified object that will be created upon first use.
+ *
+ * @param object
+ *        The object to define the lazy getter on.
+ * @param name
+ *        The name of the getter to define on object.
+ * @param lambda
+ *        A function that returns what the getter should return.  This will
+ *        only ever be called once.
+ */
+function defineLazyGetter(object, name, lambda) {
+  Object.defineProperty(object, name, {
+    get() {
+      // Redefine this accessor property as a data property.
+      // Delete it first, to rule out "too much recursion" in case object is
+      // a proxy whose defineProperty handler might unwittingly trigger this
+      // getter again.
+      delete object[name];
+      const value = lambda.apply(object);
+      Object.defineProperty(object, name, {
+        value,
+        writable: true,
+        configurable: true,
+        enumerable: true,
+      });
+      return value;
+    },
+    configurable: true,
+    enumerable: true,
+  });
+}
+
+/**
+ * Defines a getter on a specified object for a service.  The service will not
+ * be obtained until first use.
+ *
+ * @param object
+ *        The object to define the lazy getter on.
+ * @param name
+ *        The name of the getter to define on object for the service.
+ * @param contract
+ *        The contract used to obtain the service.
+ * @param interfaceName
+ *        The name of the interface to query the service to.
+ */
+function defineLazyServiceGetter(object, name, contract, interfaceName) {
+  defineLazyGetter(object, name, function () {
+    return Cc[contract].getService(Ci[interfaceName]);
+  });
+}
+
+/**
+ * Define a getter property on the given object that requires the given
+ * module. This enables delaying importing modules until the module is
+ * actually used.
+ *
+ * Several getters can be defined at once by providing an array of
+ * properties and enabling destructuring.
+ *
+ * @param { Object } obj
+ *    The object to define the property on.
+ * @param { String | Array<String> } properties
+ *    String: Name of the property for the getter.
+ *    Array<String>: When destructure is true, properties can be an array of
+ *    strings to create several getters at once.
+ * @param { String } module
+ *    The module path.
+ * @param { Boolean } destructure
+ *    Pass true if the property name is a member of the module's exports.
+ */
+function lazyRequireGetter(obj, properties, module, destructure) {
+  if (Array.isArray(properties) && !destructure) {
+    throw new Error(
+      "Pass destructure=true to call lazyRequireGetter with an array of properties"
+    );
+  }
+
+  if (!Array.isArray(properties)) {
+    properties = [properties];
+  }
+
+  for (const property of properties) {
+    defineLazyGetter(obj, property, () => {
+      return destructure
+        ? require(module)[property]
+        : require(module || property);
+    });
+  }
+}
+
+// List of pseudo modules exposed to all devtools modules.
+exports.modules = {
+  HeapSnapshot,
+  // Expose "chrome" Promise, which aren't related to any document
+  // and so are never frozen, even if the browser loader module which
+  // pull it is destroyed. See bug 1402779.
+  Promise,
+  TelemetryStopwatch,
+};
+
+defineLazyGetter(exports.modules, "Debugger", () => {
+  const global = Cu.getGlobalForObject(this);
+  // Debugger may already have been added.
+  if (global.Debugger) {
+    return global.Debugger;
+  }
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
+  );
+  addDebuggerToGlobal(global);
+  return global.Debugger;
+});
+
+defineLazyGetter(exports.modules, "ChromeDebugger", () => {
+  // Sandbox are memory expensive, so we should create as little as possible.
+  const debuggerSandbox = Cu.Sandbox(systemPrincipal, {
+    // This sandbox is used for the ChromeDebugger implementation.
+    // As we want to load the `Debugger` API for debugging chrome contexts,
+    // we have to ensure loading it in a distinct compartment from its debuggee.
+    freshCompartment: true,
+  });
+
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
+  );
+  addDebuggerToGlobal(debuggerSandbox);
+  return debuggerSandbox.Debugger;
+});
+
+defineLazyGetter(exports.modules, "xpcInspector", () => {
+  return Cc["@mozilla.org/jsinspector;1"].getService(Ci.nsIJSInspector);
+});
+
+// List of all custom globals exposed to devtools modules.
+// Changes here should be mirrored to devtools/.eslintrc.
+exports.globals = {
+  isWorker: false,
+  loader: {
+    lazyGetter: defineLazyGetter,
+    lazyServiceGetter: defineLazyServiceGetter,
+    lazyRequireGetter,
+    // Defined by Loader.sys.mjs
+    id: null,
+  },
+};
+// DevTools loader copy globals property descriptors on each module global
+// object so that we have to memoize them from here in order to instantiate each
+// global only once.
+// `globals` is a cache object on which we put all global values
+// and we set getters on `exports.globals` returning `globals` values.
+const globals = {};
+function lazyGlobal(name, getter) {
+  defineLazyGetter(globals, name, getter);
+  Object.defineProperty(exports.globals, name, {
+    get() {
+      return globals[name];
+    },
+    configurable: true,
+    enumerable: true,
+  });
+}
+
+// Lazily define a few things so that the corresponding modules are only loaded
+// when used.
+lazyGlobal("clearTimeout", () => {
+  return ChromeUtils.importESModule("resource://gre/modules/Timer.sys.mjs")
+    .clearTimeout;
+});
+lazyGlobal("setTimeout", () => {
+  return ChromeUtils.importESModule("resource://gre/modules/Timer.sys.mjs")
+    .setTimeout;
+});
+lazyGlobal("clearInterval", () => {
+  return ChromeUtils.importESModule("resource://gre/modules/Timer.sys.mjs")
+    .clearInterval;
+});
+lazyGlobal("setInterval", () => {
+  return ChromeUtils.importESModule("resource://gre/modules/Timer.sys.mjs")
+    .setInterval;
+});
+lazyGlobal("WebSocket", () => {
+  return Services.appShell.hiddenDOMWindow.WebSocket;
+});