Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 847 insertions, 0 deletions

diff --git a/devtools/server/actors/object.js b/devtools/server/actors/object.js
new file mode 100644
index 0000000000..9b52c4ebe7
--- /dev/null
+++ b/devtools/server/actors/object.js
@@ -0,0 +1,847 @@
+/* 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";
+
+const { Actor } = require("resource://devtools/shared/protocol/Actor.js");
+const { objectSpec } = require("resource://devtools/shared/specs/object.js");
+
+const DevToolsUtils = require("resource://devtools/shared/DevToolsUtils.js");
+const { assert } = DevToolsUtils;
+
+loader.lazyRequireGetter(
+  this,
+  "PropertyIteratorActor",
+  "resource://devtools/server/actors/object/property-iterator.js",
+  true
+);
+loader.lazyRequireGetter(
+  this,
+  "SymbolIteratorActor",
+  "resource://devtools/server/actors/object/symbol-iterator.js",
+  true
+);
+loader.lazyRequireGetter(
+  this,
+  "PrivatePropertiesIteratorActor",
+  "resource://devtools/server/actors/object/private-properties-iterator.js",
+  true
+);
+loader.lazyRequireGetter(
+  this,
+  "previewers",
+  "resource://devtools/server/actors/object/previewers.js"
+);
+
+loader.lazyRequireGetter(
+  this,
+  ["customFormatterHeader", "customFormatterBody"],
+  "resource://devtools/server/actors/utils/custom-formatters.js",
+  true
+);
+
+// This is going to be used by findSafeGetters, where we want to avoid calling getters for
+// deprecated properties (otherwise a warning message is displayed in the console).
+// We could do something like EagerEvaluation, where we create a new Sandbox which is then
+// used to compare functions, but, we'd need to make new classes available in
+// the Sandbox, and possibly do it again when a new property gets deprecated.
+// Since this is only to be able to automatically call getters, we can simply check against
+// a list of unsafe getters that we generate from webidls.
+loader.lazyRequireGetter(
+  this,
+  "unsafeGettersNames",
+  "resource://devtools/server/actors/webconsole/webidl-unsafe-getters-names.js"
+);
+
+// ContentDOMReference requires ChromeUtils, which isn't available in worker context.
+const lazy = {};
+if (!isWorker) {
+  loader.lazyGetter(
+    lazy,
+    "ContentDOMReference",
+    () =>
+      ChromeUtils.importESModule(
+        "resource://gre/modules/ContentDOMReference.sys.mjs",
+        {
+          // ContentDOMReference needs to be retrieved from the shared global
+          // since it is a shared singleton.
+          loadInDevToolsLoader: false,
+        }
+      ).ContentDOMReference
+  );
+}
+
+const {
+  getArrayLength,
+  getPromiseState,
+  getStorageLength,
+  isArray,
+  isStorage,
+  isTypedArray,
+} = require("resource://devtools/server/actors/object/utils.js");
+
+class ObjectActor extends Actor {
+  /**
+   * Creates an actor for the specified object.
+   *
+   * @param obj Debugger.Object
+   *        The debuggee object.
+   * @param Object
+   *        A collection of abstract methods that are implemented by the caller.
+   *        ObjectActor requires the following functions to be implemented by
+   *        the caller:
+   *          - createValueGrip
+   *              Creates a value grip for the given object
+   *          - createEnvironmentActor
+   *              Creates and return an environment actor
+   *          - getGripDepth
+   *              An actor's grip depth getter
+   *          - incrementGripDepth
+   *              Increment the actor's grip depth
+   *          - decrementGripDepth
+   *              Decrement the actor's grip depth
+   * @param DevToolsServerConnection conn
+   */
+  constructor(
+    obj,
+    {
+      thread,
+      createValueGrip: createValueGripHook,
+      createEnvironmentActor,
+      getGripDepth,
+      incrementGripDepth,
+      decrementGripDepth,
+      customFormatterObjectTagDepth,
+      customFormatterConfigDbgObj,
+    },
+    conn
+  ) {
+    super(conn, objectSpec);
+
+    assert(
+      !obj.optimizedOut,
+      "Should not create object actors for optimized out values!"
+    );
+
+    this.obj = obj;
+    this.thread = thread;
+    this.hooks = {
+      createValueGrip: createValueGripHook,
+      createEnvironmentActor,
+      getGripDepth,
+      incrementGripDepth,
+      decrementGripDepth,
+      customFormatterObjectTagDepth,
+      customFormatterConfigDbgObj,
+    };
+  }
+
+  rawValue() {
+    return this.obj.unsafeDereference();
+  }
+
+  addWatchpoint(property, label, watchpointType) {
+    this.thread.addWatchpoint(this, { property, label, watchpointType });
+  }
+
+  removeWatchpoint(property) {
+    this.thread.removeWatchpoint(this, property);
+  }
+
+  removeWatchpoints() {
+    this.thread.removeWatchpoint(this);
+  }
+
+  /**
+   * Returns a grip for this actor for returning in a protocol message.
+   */
+  form() {
+    const g = {
+      type: "object",
+      actor: this.actorID,
+    };
+
+    const unwrapped = DevToolsUtils.unwrap(this.obj);
+    if (unwrapped === undefined) {
+      // Objects belonging to an invisible-to-debugger compartment might be proxies,
+      // so just in case they shouldn't be accessed.
+      g.class = "InvisibleToDebugger: " + this.obj.class;
+      return g;
+    }
+
+    // Only process custom formatters if the feature is enabled.
+    if (this.thread?._parent?.customFormatters) {
+      const result = customFormatterHeader(this);
+      if (result) {
+        const { formatter, ...header } = result;
+        this._customFormatterItem = formatter;
+
+        return {
+          ...g,
+          ...header,
+        };
+      }
+    }
+
+    if (unwrapped?.isProxy) {
+      // Proxy objects can run traps when accessed, so just create a preview with
+      // the target and the handler.
+      g.class = "Proxy";
+      this.hooks.incrementGripDepth();
+      previewers.Proxy[0](this, g, null);
+      this.hooks.decrementGripDepth();
+      return g;
+    }
+
+    const ownPropertyLength = this._getOwnPropertyLength();
+
+    Object.assign(g, {
+      // If the debuggee does not subsume the object's compartment, most properties won't
+      // be accessible. Cross-orgin Window and Location objects might expose some, though.
+      // Change the displayed class, but when creating the preview use the original one.
+      class: unwrapped === null ? "Restricted" : this.obj.class,
+      ownPropertyLength: Number.isFinite(ownPropertyLength)
+        ? ownPropertyLength
+        : undefined,
+      extensible: this.obj.isExtensible(),
+      frozen: this.obj.isFrozen(),
+      sealed: this.obj.isSealed(),
+      isError: this.obj.isError,
+    });
+
+    this.hooks.incrementGripDepth();
+
+    if (g.class == "Function") {
+      g.isClassConstructor = this.obj.isClassConstructor;
+    }
+
+    const raw = this.getRawObject();
+    this._populateGripPreview(g, raw);
+    this.hooks.decrementGripDepth();
+
+    if (raw && Node.isInstance(raw) && lazy.ContentDOMReference) {
+      // ContentDOMReference.get takes a DOM element and returns an object with
+      // its browsing context id, as well as a unique identifier. We are putting it in
+      // the grip here in order to be able to retrieve the node later, potentially from a
+      // different DevToolsServer running in the same process.
+      // If ContentDOMReference.get throws, we simply don't add the property to the grip.
+      try {
+        g.contentDomReference = lazy.ContentDOMReference.get(raw);
+      } catch (e) {}
+    }
+
+    return g;
+  }
+
+  customFormatterBody() {
+    return customFormatterBody(this, this._customFormatterItem);
+  }
+
+  _getOwnPropertyLength() {
+    if (isTypedArray(this.obj)) {
+      // Bug 1348761: getOwnPropertyNames is unnecessary slow on TypedArrays
+      return getArrayLength(this.obj);
+    }
+
+    if (isStorage(this.obj)) {
+      return getStorageLength(this.obj);
+    }
+
+    try {
+      return this.obj.getOwnPropertyNamesLength();
+    } catch (err) {
+      // The above can throw when the debuggee does not subsume the object's
+      // compartment, or for some WrappedNatives like Cu.Sandbox.
+    }
+
+    return null;
+  }
+
+  getRawObject() {
+    let raw = this.obj.unsafeDereference();
+
+    // If Cu is not defined, we are running on a worker thread, where xrays
+    // don't exist.
+    if (raw && Cu) {
+      raw = Cu.unwaiveXrays(raw);
+    }
+
+    if (raw && !DevToolsUtils.isSafeJSObject(raw)) {
+      raw = null;
+    }
+
+    return raw;
+  }
+
+  /**
+   * Populate the `preview` property on `grip` given its type.
+   */
+  _populateGripPreview(grip, raw) {
+    // Cache obj.class as it can be costly if this is in a hot path (e.g. logging objects
+    // within a for loop).
+    const className = this.obj.class;
+    for (const previewer of previewers[className] || previewers.Object) {
+      try {
+        const previewerResult = previewer(this, grip, raw, className);
+        if (previewerResult) {
+          return;
+        }
+      } catch (e) {
+        const msg =
+          "ObjectActor.prototype._populateGripPreview previewer function";
+        DevToolsUtils.reportException(msg, e);
+      }
+    }
+  }
+
+  /**
+   * Returns an object exposing the internal Promise state.
+   */
+  promiseState() {
+    const { state, value, reason } = getPromiseState(this.obj);
+    const promiseState = { state };
+
+    if (state == "fulfilled") {
+      promiseState.value = this.hooks.createValueGrip(value);
+    } else if (state == "rejected") {
+      promiseState.reason = this.hooks.createValueGrip(reason);
+    }
+
+    promiseState.creationTimestamp = Date.now() - this.obj.promiseLifetime;
+
+    // Only add the timeToSettle property if the Promise isn't pending.
+    if (state !== "pending") {
+      promiseState.timeToSettle = this.obj.promiseTimeToResolution;
+    }
+
+    return { promiseState };
+  }
+
+  /**
+   * Creates an actor to iterate over an object property names and values.
+   * See PropertyIteratorActor constructor for more info about options param.
+   *
+   * @param options object
+   */
+  enumProperties(options) {
+    return new PropertyIteratorActor(this, options, this.conn);
+  }
+
+  /**
+   * Creates an actor to iterate over entries of a Map/Set-like object.
+   */
+  enumEntries() {
+    return new PropertyIteratorActor(this, { enumEntries: true }, this.conn);
+  }
+
+  /**
+   * Creates an actor to iterate over an object symbols properties.
+   */
+  enumSymbols() {
+    return new SymbolIteratorActor(this, this.conn);
+  }
+
+  /**
+   * Creates an actor to iterate over an object private properties.
+   */
+  enumPrivateProperties() {
+    return new PrivatePropertiesIteratorActor(this, this.conn);
+  }
+
+  /**
+   * Handle a protocol request to provide the prototype and own properties of
+   * the object.
+   *
+   * @returns {Object} An object containing the data of this.obj, of the following form:
+   *          - {Object} prototype: The descriptor of this.obj's prototype.
+   *          - {Object} ownProperties: an object where the keys are the names of the
+   *                     this.obj's ownProperties, and the values the descriptors of
+   *                     the properties.
+   *          - {Array} ownSymbols: An array containing all descriptors of this.obj's
+   *                    ownSymbols. Here we have an array, and not an object like for
+   *                    ownProperties, because we can have multiple symbols with the same
+   *                    name in this.obj, e.g. `{[Symbol()]: "a", [Symbol()]: "b"}`.
+   *          - {Object} safeGetterValues: an object that maps this.obj's property names
+   *                     with safe getters descriptors.
+   */
+  prototypeAndProperties() {
+    let objProto = null;
+    let names = [];
+    let symbols = [];
+    if (DevToolsUtils.isSafeDebuggerObject(this.obj)) {
+      try {
+        objProto = this.obj.proto;
+        names = this.obj.getOwnPropertyNames();
+        symbols = this.obj.getOwnPropertySymbols();
+      } catch (err) {
+        // The above can throw when the debuggee does not subsume the object's
+        // compartment, or for some WrappedNatives like Cu.Sandbox.
+      }
+    }
+
+    const ownProperties = Object.create(null);
+    const ownSymbols = [];
+
+    for (const name of names) {
+      ownProperties[name] = this._propertyDescriptor(name);
+    }
+
+    for (const sym of symbols) {
+      ownSymbols.push({
+        name: sym.toString(),
+        descriptor: this._propertyDescriptor(sym),
+      });
+    }
+
+    return {
+      prototype: this.hooks.createValueGrip(objProto),
+      ownProperties,
+      ownSymbols,
+      safeGetterValues: this._findSafeGetterValues(names),
+    };
+  }
+
+  /**
+   * Find the safe getter values for the current Debugger.Object, |this.obj|.
+   *
+   * @private
+   * @param array ownProperties
+   *        The array that holds the list of known ownProperties names for
+   *        |this.obj|.
+   * @param number [limit=Infinity]
+   *        Optional limit of getter values to find.
+   * @return object
+   *         An object that maps property names to safe getter descriptors as
+   *         defined by the remote debugging protocol.
+   */
+  _findSafeGetterValues(ownProperties, limit = Infinity) {
+    const safeGetterValues = Object.create(null);
+    let obj = this.obj;
+    let level = 0,
+      currentGetterValuesCount = 0;
+
+    // Do not search safe getters in unsafe objects.
+    if (!DevToolsUtils.isSafeDebuggerObject(obj)) {
+      return safeGetterValues;
+    }
+
+    // Most objects don't have any safe getters but inherit some from their
+    // prototype. Avoid calling getOwnPropertyNames on objects that may have
+    // many properties like Array, strings or js objects. That to avoid
+    // freezing firefox when doing so.
+    if (isArray(this.obj) || ["Object", "String"].includes(this.obj.class)) {
+      obj = obj.proto;
+      level++;
+    }
+
+    while (obj && DevToolsUtils.isSafeDebuggerObject(obj)) {
+      for (const name of this._findSafeGetters(obj)) {
+        // Avoid overwriting properties from prototypes closer to this.obj. Also
+        // avoid providing safeGetterValues from prototypes if property |name|
+        // is already defined as an own property.
+        if (
+          name in safeGetterValues ||
+          (obj != this.obj && ownProperties.includes(name))
+        ) {
+          continue;
+        }
+
+        // Ignore __proto__ on Object.prototye.
+        if (!obj.proto && name == "__proto__") {
+          continue;
+        }
+
+        const desc = safeGetOwnPropertyDescriptor(obj, name);
+        if (!desc?.get) {
+          // If no getter matches the name, the cache is stale and should be cleaned up.
+          obj._safeGetters = null;
+          continue;
+        }
+
+        const getterValue = this._evaluateGetter(desc.get);
+        if (getterValue === undefined) {
+          continue;
+        }
+
+        // Treat an already-rejected Promise as we would a thrown exception
+        // by not including it as a safe getter value (see Bug 1477765).
+        if (isRejectedPromise(getterValue)) {
+          // Until we have a good way to handle Promise rejections through the
+          // debugger API (Bug 1478076), call `catch` when it's safe to do so.
+          const raw = getterValue.unsafeDereference();
+          if (DevToolsUtils.isSafeJSObject(raw)) {
+            raw.catch(e => e);
+          }
+          continue;
+        }
+
+        // WebIDL attributes specified with the LenientThis extended attribute
+        // return undefined and should be ignored.
+        safeGetterValues[name] = {
+          getterValue: this.hooks.createValueGrip(getterValue),
+          getterPrototypeLevel: level,
+          enumerable: desc.enumerable,
+          writable: level == 0 ? desc.writable : true,
+        };
+
+        ++currentGetterValuesCount;
+        if (currentGetterValuesCount == limit) {
+          return safeGetterValues;
+        }
+      }
+
+      obj = obj.proto;
+      level++;
+    }
+
+    return safeGetterValues;
+  }
+
+  /**
+   * Evaluate the getter function |desc.get|.
+   * @param {Object} getter
+   */
+  _evaluateGetter(getter) {
+    const result = getter.call(this.obj);
+    if (!result || "throw" in result) {
+      return undefined;
+    }
+
+    let getterValue = undefined;
+    if ("return" in result) {
+      getterValue = result.return;
+    } else if ("yield" in result) {
+      getterValue = result.yield;
+    }
+
+    return getterValue;
+  }
+
+  /**
+   * Find the safe getters for a given Debugger.Object. Safe getters are native
+   * getters which are safe to execute.
+   *
+   * @private
+   * @param Debugger.Object object
+   *        The Debugger.Object where you want to find safe getters.
+   * @return Set
+   *         A Set of names of safe getters. This result is cached for each
+   *         Debugger.Object.
+   */
+  _findSafeGetters(object) {
+    if (object._safeGetters) {
+      return object._safeGetters;
+    }
+
+    const getters = new Set();
+
+    if (!DevToolsUtils.isSafeDebuggerObject(object)) {
+      object._safeGetters = getters;
+      return getters;
+    }
+
+    let names = [];
+    try {
+      names = object.getOwnPropertyNames();
+    } catch (ex) {
+      // Calling getOwnPropertyNames() on some wrapped native prototypes is not
+      // allowed: "cannot modify properties of a WrappedNative". See bug 952093.
+    }
+
+    for (const name of names) {
+      let desc = null;
+      try {
+        desc = object.getOwnPropertyDescriptor(name);
+      } catch (e) {
+        // Calling getOwnPropertyDescriptor on wrapped native prototypes is not
+        // allowed (bug 560072).
+      }
+      if (!desc || desc.value !== undefined || !("get" in desc)) {
+        continue;
+      }
+
+      if (
+        DevToolsUtils.hasSafeGetter(desc) &&
+        !unsafeGettersNames.includes(name)
+      ) {
+        getters.add(name);
+      }
+    }
+
+    object._safeGetters = getters;
+    return getters;
+  }
+
+  /**
+   * Handle a protocol request to provide the prototype of the object.
+   */
+  prototype() {
+    let objProto = null;
+    if (DevToolsUtils.isSafeDebuggerObject(this.obj)) {
+      objProto = this.obj.proto;
+    }
+    return { prototype: this.hooks.createValueGrip(objProto) };
+  }
+
+  /**
+   * Handle a protocol request to provide the property descriptor of the
+   * object's specified property.
+   *
+   * @param name string
+   *        The property we want the description of.
+   */
+  property(name) {
+    if (!name) {
+      return this.throwError(
+        "missingParameter",
+        "no property name was specified"
+      );
+    }
+
+    return { descriptor: this._propertyDescriptor(name) };
+  }
+
+  /**
+   * Handle a protocol request to provide the value of the object's
+   * specified property.
+   *
+   * Note: Since this will evaluate getters, it can trigger execution of
+   * content code and may cause side effects. This endpoint should only be used
+   * when you are confident that the side-effects will be safe, or the user
+   * is expecting the effects.
+   *
+   * @param {string} name
+   *        The property we want the value of.
+   * @param {string|null} receiverId
+   *        The actorId of the receiver to be used if the property is a getter.
+   *        If null or invalid, the receiver will be the referent.
+   */
+  propertyValue(name, receiverId) {
+    if (!name) {
+      return this.throwError(
+        "missingParameter",
+        "no property name was specified"
+      );
+    }
+
+    let receiver;
+    if (receiverId) {
+      const receiverActor = this.conn.getActor(receiverId);
+      if (receiverActor) {
+        receiver = receiverActor.obj;
+      }
+    }
+
+    const value = receiver
+      ? this.obj.getProperty(name, receiver)
+      : this.obj.getProperty(name);
+
+    return { value: this._buildCompletion(value) };
+  }
+
+  /**
+   * Handle a protocol request to evaluate a function and provide the value of
+   * the result.
+   *
+   * Note: Since this will evaluate the function, it can trigger execution of
+   * content code and may cause side effects. This endpoint should only be used
+   * when you are confident that the side-effects will be safe, or the user
+   * is expecting the effects.
+   *
+   * @param {any} context
+   *        The 'this' value to call the function with.
+   * @param {Array<any>} args
+   *        The array of un-decoded actor objects, or primitives.
+   */
+  apply(context, args) {
+    if (!this.obj.callable) {
+      return this.throwError("notCallable", "debugee object is not callable");
+    }
+
+    const debugeeContext = this._getValueFromGrip(context);
+    const debugeeArgs = args && args.map(this._getValueFromGrip, this);
+
+    const value = this.obj.apply(debugeeContext, debugeeArgs);
+
+    return { value: this._buildCompletion(value) };
+  }
+
+  _getValueFromGrip(grip) {
+    if (typeof grip !== "object" || !grip) {
+      return grip;
+    }
+
+    if (typeof grip.actor !== "string") {
+      return this.throwError(
+        "invalidGrip",
+        "grip argument did not include actor ID"
+      );
+    }
+
+    const actor = this.conn.getActor(grip.actor);
+
+    if (!actor) {
+      return this.throwError(
+        "unknownActor",
+        "grip actor did not match a known object"
+      );
+    }
+
+    return actor.obj;
+  }
+
+  /**
+   * Converts a Debugger API completion value record into an equivalent
+   * object grip for use by the API.
+   *
+   * See https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/
+   * for more specifics on the expected behavior.
+   */
+  _buildCompletion(value) {
+    let completionGrip = null;
+
+    // .apply result will be falsy if the script being executed is terminated
+    // via the "slow script" dialog.
+    if (value) {
+      completionGrip = {};
+      if ("return" in value) {
+        completionGrip.return = this.hooks.createValueGrip(value.return);
+      }
+      if ("throw" in value) {
+        completionGrip.throw = this.hooks.createValueGrip(value.throw);
+      }
+    }
+
+    return completionGrip;
+  }
+
+  /**
+   * A helper method that creates a property descriptor for the provided object,
+   * properly formatted for sending in a protocol response.
+   *
+   * @private
+   * @param string name
+   *        The property that the descriptor is generated for.
+   * @param boolean [onlyEnumerable]
+   *        Optional: true if you want a descriptor only for an enumerable
+   *        property, false otherwise.
+   * @return object|undefined
+   *         The property descriptor, or undefined if this is not an enumerable
+   *         property and onlyEnumerable=true.
+   */
+  _propertyDescriptor(name, onlyEnumerable) {
+    if (!DevToolsUtils.isSafeDebuggerObject(this.obj)) {
+      return undefined;
+    }
+
+    let desc;
+    try {
+      desc = this.obj.getOwnPropertyDescriptor(name);
+    } catch (e) {
+      // Calling getOwnPropertyDescriptor on wrapped native prototypes is not
+      // allowed (bug 560072). Inform the user with a bogus, but hopefully
+      // explanatory, descriptor.
+      return {
+        configurable: false,
+        writable: false,
+        enumerable: false,
+        value: e.name,
+      };
+    }
+
+    if (isStorage(this.obj)) {
+      if (name === "length") {
+        return undefined;
+      }
+      return desc;
+    }
+
+    if (!desc || (onlyEnumerable && !desc.enumerable)) {
+      return undefined;
+    }
+
+    const retval = {
+      configurable: desc.configurable,
+      enumerable: desc.enumerable,
+    };
+    const obj = this.rawValue();
+
+    if ("value" in desc) {
+      retval.writable = desc.writable;
+      retval.value = this.hooks.createValueGrip(desc.value);
+    } else if (this.thread.getWatchpoint(obj, name.toString())) {
+      const watchpoint = this.thread.getWatchpoint(obj, name.toString());
+      retval.value = this.hooks.createValueGrip(watchpoint.desc.value);
+      retval.watchpoint = watchpoint.watchpointType;
+    } else {
+      if ("get" in desc) {
+        retval.get = this.hooks.createValueGrip(desc.get);
+      }
+
+      if ("set" in desc) {
+        retval.set = this.hooks.createValueGrip(desc.set);
+      }
+    }
+    return retval;
+  }
+
+  /**
+   * Handle a protocol request to get the target and handler internal slots of a proxy.
+   */
+  proxySlots() {
+    // There could be transparent security wrappers, unwrap to check if it's a proxy.
+    // However, retrieve proxyTarget and proxyHandler from `this.obj` to avoid exposing
+    // the unwrapped target and handler.
+    const unwrapped = DevToolsUtils.unwrap(this.obj);
+    if (!unwrapped || !unwrapped.isProxy) {
+      return this.throwError(
+        "objectNotProxy",
+        "'proxySlots' request is only valid for grips with a 'Proxy' class."
+      );
+    }
+    return {
+      proxyTarget: this.hooks.createValueGrip(this.obj.proxyTarget),
+      proxyHandler: this.hooks.createValueGrip(this.obj.proxyHandler),
+    };
+  }
+
+  /**
+   * Release the actor, when it isn't needed anymore.
+   * Protocol.js uses this release method to call the destroy method.
+   */
+  release() {
+    if (this.hooks) {
+      this.hooks.customFormatterConfigDbgObj = null;
+    }
+    this._customFormatterItem = null;
+    this.obj = null;
+    this.thread = null;
+  }
+}
+
+exports.ObjectActor = ObjectActor;
+
+function safeGetOwnPropertyDescriptor(obj, name) {
+  let desc = null;
+  try {
+    desc = obj.getOwnPropertyDescriptor(name);
+  } catch (ex) {
+    // The above can throw if the cache becomes stale.
+  }
+  return desc;
+}
+
+/**
+ * Check if the value is rejected promise
+ *
+ * @param {Object} getterValue
+ * @returns {boolean} true if the value is rejected promise, false otherwise.
+ */
+function isRejectedPromise(getterValue) {
+  return (
+    getterValue &&
+    getterValue.class == "Promise" &&
+    getterValue.promiseState == "rejected"
+  );
+}