1 files changed, 564 insertions, 0 deletions
diff --git a/devtools/server/actors/object/utils.js b/devtools/server/actors/object/utils.js
new file mode 100644
index 0000000000..3c40aa8150
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+++ b/devtools/server/actors/object/utils.js
@@ -0,0 +1,564 @@
+/* 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 { DevToolsServer } = require("resource://devtools/server/devtools-server.js");
+const DevToolsUtils = require("resource://devtools/shared/DevToolsUtils.js");
+const { assert } = DevToolsUtils;
+
+loader.lazyRequireGetter(
+  this,
+  "LongStringActor",
+  "resource://devtools/server/actors/string.js",
+  true
+);
+
+loader.lazyRequireGetter(
+  this,
+  "symbolGrip",
+  "resource://devtools/server/actors/object/symbol.js",
+  true
+);
+
+loader.lazyRequireGetter(
+  this,
+  "ObjectActor",
+  "resource://devtools/server/actors/object.js",
+  true
+);
+
+loader.lazyRequireGetter(
+  this,
+  "EnvironmentActor",
+  "resource://devtools/server/actors/environment.js",
+  true
+);
+
+/**
+ * Get thisDebugger.Object referent's `promiseState`.
+ *
+ * @returns Object
+ *          An object of one of the following forms:
+ *          - { state: "pending" }
+ *          - { state: "fulfilled", value }
+ *          - { state: "rejected", reason }
+ */
+function getPromiseState(obj) {
+  if (obj.class != "Promise") {
+    throw new Error(
+      "Can't call `getPromiseState` on `Debugger.Object`s that don't " +
+        "refer to Promise objects."
+    );
+  }
+
+  const state = { state: obj.promiseState };
+  if (state.state === "fulfilled") {
+    state.value = obj.promiseValue;
+  } else if (state.state === "rejected") {
+    state.reason = obj.promiseReason;
+  }
+  return state;
+}
+
+/**
+ * Returns true if value is an object or function
+ *
+ * @param value
+ * @returns {boolean}
+ */
+
+function isObjectOrFunction(value) {
+  return value && (typeof value == "object" || typeof value == "function");
+}
+
+/**
+ * Make a debuggee value for the given object, if needed. Primitive values
+ * are left the same.
+ *
+ * Use case: you have a raw JS object (after unsafe dereference) and you want to
+ * send it to the client. In that case you need to use an ObjectActor which
+ * requires a debuggee value. The Debugger.Object.prototype.makeDebuggeeValue()
+ * method works only for JS objects and functions.
+ *
+ * @param Debugger.Object obj
+ * @param any value
+ * @return object
+ */
+function makeDebuggeeValueIfNeeded(obj, value) {
+  if (isObjectOrFunction(value)) {
+    return obj.makeDebuggeeValue(value);
+  }
+  return value;
+}
+
+/**
+ * Convert a debuggee value into the underlying raw object, if needed.
+ */
+function unwrapDebuggeeValue(value) {
+  if (value && typeof value == "object") {
+    return value.unsafeDereference();
+  }
+  return value;
+}
+
+/**
+ * Create a grip for the given debuggee value. If the value is an object or a long string,
+ * it will create an actor and add it to the pool
+ * @param {any} value: The debuggee value.
+ * @param {Pool} pool: The pool where the created actor will be added.
+ * @param {Function} makeObjectGrip: Function that will be called to create the grip for
+ *                                   non-primitive values.
+ */
+function createValueGrip(value, pool, makeObjectGrip) {
+  switch (typeof value) {
+    case "boolean":
+      return value;
+
+    case "string":
+      return createStringGrip(pool, value);
+
+    case "number":
+      if (value === Infinity) {
+        return { type: "Infinity" };
+      } else if (value === -Infinity) {
+        return { type: "-Infinity" };
+      } else if (Number.isNaN(value)) {
+        return { type: "NaN" };
+      } else if (!value && 1 / value === -Infinity) {
+        return { type: "-0" };
+      }
+      return value;
+
+    case "bigint":
+      return {
+        type: "BigInt",
+        text: value.toString(),
+      };
+
+    // TODO(bug 1772157)
+    // Record/tuple grips aren't fully implemented yet.
+    case "record":
+      return {
+        class: "Record",
+      };
+    case "tuple":
+      return {
+        class: "Tuple",
+      };
+    case "undefined":
+      return { type: "undefined" };
+
+    case "object":
+      if (value === null) {
+        return { type: "null" };
+      } else if (
+        value.optimizedOut ||
+        value.uninitialized ||
+        value.missingArguments
+      ) {
+        // The slot is optimized out, an uninitialized binding, or
+        // arguments on a dead scope
+        return {
+          type: "null",
+          optimizedOut: value.optimizedOut,
+          uninitialized: value.uninitialized,
+          missingArguments: value.missingArguments,
+        };
+      }
+      return makeObjectGrip(value, pool);
+
+    case "symbol":
+      return symbolGrip(value, pool);
+
+    default:
+      assert(false, "Failed to provide a grip for: " + value);
+      return null;
+  }
+}
+
+/**
+ * of passing the value directly over the protocol.
+ *
+ * @param str String
+ *        The string we are checking the length of.
+ */
+function stringIsLong(str) {
+  return str.length >= DevToolsServer.LONG_STRING_LENGTH;
+}
+
+const TYPED_ARRAY_CLASSES = [
+  "Uint8Array",
+  "Uint8ClampedArray",
+  "Uint16Array",
+  "Uint32Array",
+  "Int8Array",
+  "Int16Array",
+  "Int32Array",
+  "Float32Array",
+  "Float64Array",
+  "BigInt64Array",
+  "BigUint64Array",
+];
+
+/**
+ * Returns true if a debuggee object is a typed array.
+ *
+ * @param obj Debugger.Object
+ *        The debuggee object to test.
+ * @return Boolean
+ */
+function isTypedArray(object) {
+  return TYPED_ARRAY_CLASSES.includes(object.class);
+}
+
+/**
+ * Returns true if a debuggee object is an array, including a typed array.
+ *
+ * @param obj Debugger.Object
+ *        The debuggee object to test.
+ * @return Boolean
+ */
+function isArray(object) {
+  return isTypedArray(object) || object.class === "Array";
+}
+
+/**
+ * Returns the length of an array (or typed array).
+ *
+ * @param object Debugger.Object
+ *        The debuggee object of the array.
+ * @return Number
+ * @throws if the object is not an array.
+ */
+function getArrayLength(object) {
+  if (!isArray(object)) {
+    throw new Error("Expected an array, got a " + object.class);
+  }
+
+  // Real arrays have a reliable `length` own property.
+  if (object.class === "Array") {
+    return DevToolsUtils.getProperty(object, "length");
+  }
+
+  // For typed arrays, `DevToolsUtils.getProperty` is not reliable because the `length`
+  // getter could be shadowed by an own property, and `getOwnPropertyNames` is
+  // unnecessarily slow. Obtain the `length` getter safely and call it manually.
+  const typedProto = Object.getPrototypeOf(Uint8Array.prototype);
+  const getter = Object.getOwnPropertyDescriptor(typedProto, "length").get;
+  return getter.call(object.unsafeDereference());
+}
+
+/**
+ * Returns true if the parameter is suitable to be an array index.
+ *
+ * @param str String
+ * @return Boolean
+ */
+function isArrayIndex(str) {
+  // Transform the parameter to a 32-bit unsigned integer.
+  const num = str >>> 0;
+  // Check that the parameter is a canonical Uint32 index.
+  return (
+    num + "" === str &&
+    // Array indices cannot attain the maximum Uint32 value.
+    num != -1 >>> 0
+  );
+}
+
+/**
+ * Returns true if a debuggee object is a local or sessionStorage object.
+ *
+ * @param object Debugger.Object
+ *        The debuggee object to test.
+ * @return Boolean
+ */
+function isStorage(object) {
+  return object.class === "Storage";
+}
+
+/**
+ * Returns the length of a local or sessionStorage object.
+ *
+ * @param object Debugger.Object
+ *        The debuggee object of the array.
+ * @return Number
+ * @throws if the object is not a local or sessionStorage object.
+ */
+function getStorageLength(object) {
+  if (!isStorage(object)) {
+    throw new Error("Expected a storage object, got a " + object.class);
+  }
+  return DevToolsUtils.getProperty(object, "length");
+}
+
+/**
+ * Returns an array of properties based on event class name.
+ *
+ * @param className
+ * @returns {Array}
+ */
+function getPropsForEvent(className) {
+  const positionProps = ["buttons", "clientX", "clientY", "layerX", "layerY"];
+  const eventToPropsMap = {
+    MouseEvent: positionProps,
+    DragEvent: positionProps,
+    PointerEvent: positionProps,
+    SimpleGestureEvent: positionProps,
+    WheelEvent: positionProps,
+    KeyboardEvent: ["key", "charCode", "keyCode"],
+    TransitionEvent: ["propertyName", "pseudoElement"],
+    AnimationEvent: ["animationName", "pseudoElement"],
+    ClipboardEvent: ["clipboardData"],
+  };
+
+  if (className in eventToPropsMap) {
+    return eventToPropsMap[className];
+  }
+
+  return [];
+}
+
+/**
+ * Returns an array of of all properties of an object
+ *
+ * @param obj
+ * @param rawObj
+ * @returns {Array|Iterable} If rawObj is localStorage/sessionStorage, we don't return an
+ *          array but an iterable object (with the proper `length` property) to avoid
+ *          performance issues.
+ */
+function getPropNamesFromObject(obj, rawObj) {
+  try {
+    if (isStorage(obj)) {
+      // local and session storage cannot be iterated over using
+      // Object.getOwnPropertyNames() because it skips keys that are duplicated
+      // on the prototype e.g. "key", "getKeys" so we need to gather the real
+      // keys using the storage.key() function.
+      // As the method is pretty slow, we return an iterator here, so we don't consume
+      // more than we need, especially since we're calling this from previewers in which
+      // we only need the first 10 entries for the preview (See Bug 1741804).
+
+      // Still return the proper number of entries.
+      const length = rawObj.length;
+      const iterable = { length };
+      iterable[Symbol.iterator] = function*() {
+        for (let j = 0; j < length; j++) {
+          yield rawObj.key(j);
+        }
+      };
+      return iterable;
+    }
+
+    return obj.getOwnPropertyNames();
+  } catch (ex) {
+    // Calling getOwnPropertyNames() on some wrapped native prototypes is not
+    // allowed: "cannot modify properties of a WrappedNative". See bug 952093.
+  }
+
+  return [];
+}
+
+/**
+ * Returns an array of private properties of an object
+ *
+ * @param obj
+ * @returns {Array}
+ */
+function getSafePrivatePropertiesSymbols(obj) {
+  try {
+    return obj.getOwnPrivateProperties();
+  } catch (ex) {
+    return [];
+  }
+}
+
+/**
+ * Returns an array of all symbol properties of an object
+ *
+ * @param obj
+ * @returns {Array}
+ */
+function getSafeOwnPropertySymbols(obj) {
+  try {
+    return obj.getOwnPropertySymbols();
+  } catch (ex) {
+    return [];
+  }
+}
+
+/**
+ * Returns an array modifiers based on keys
+ *
+ * @param rawObj
+ * @returns {Array}
+ */
+function getModifiersForEvent(rawObj) {
+  const modifiers = [];
+  const keysToModifiersMap = {
+    altKey: "Alt",
+    ctrlKey: "Control",
+    metaKey: "Meta",
+    shiftKey: "Shift",
+  };
+
+  for (const key in keysToModifiersMap) {
+    if (keysToModifiersMap.hasOwnProperty(key) && rawObj[key]) {
+      modifiers.push(keysToModifiersMap[key]);
+    }
+  }
+
+  return modifiers;
+}
+
+/**
+ * Make a debuggee value for the given value.
+ *
+ * @param TargetActor targetActor
+ *        The Target Actor from which this object originates.
+ * @param mixed value
+ *        The value you want to get a debuggee value for.
+ * @return object
+ *         Debuggee value for |value|.
+ */
+function makeDebuggeeValue(targetActor, value) {
+  if (isObject(value)) {
+    try {
+      const global = Cu.getGlobalForObject(value);
+      const dbgGlobal = targetActor.dbg.makeGlobalObjectReference(global);
+      return dbgGlobal.makeDebuggeeValue(value);
+    } catch (ex) {
+      // The above can throw an exception if value is not an actual object
+      // or 'Object in compartment marked as invisible to Debugger'
+    }
+  }
+  const dbgGlobal = targetActor.dbg.makeGlobalObjectReference(
+    targetActor.window || targetActor.workerGlobal
+  );
+  return dbgGlobal.makeDebuggeeValue(value);
+}
+
+function isObject(value) {
+  return Object(value) === value;
+}
+
+/**
+ * Create a grip for the given string.
+ *
+ * @param TargetActor targetActor
+ *        The Target Actor from which this object originates.
+ */
+function createStringGrip(targetActor, string) {
+  if (string && stringIsLong(string)) {
+    const actor = new LongStringActor(targetActor.conn, string);
+    targetActor.manage(actor);
+    return actor.form();
+  }
+  return string;
+}
+
+/**
+ * Create a grip for the given value.
+ *
+ * @param TargetActor targetActor
+ *        The Target Actor from which this object originates.
+ * @param mixed value
+ *        The value you want to get a debuggee value for.
+ * @param Number depth
+ *        Depth of the object compared to the top level object,
+ *        when we are inspecting nested attributes.
+ * @return object
+ */
+function createValueGripForTarget(targetActor, value, depth = 0) {
+  return createValueGrip(
+    value,
+    targetActor,
+    createObjectGrip.bind(null, targetActor, depth)
+  );
+}
+
+/**
+ * Create and return an environment actor that corresponds to the provided
+ * Debugger.Environment. This is a straightforward clone of the ThreadActor's
+ * method except that it stores the environment actor in the web console
+ * actor's pool.
+ *
+ * @param Debugger.Environment environment
+ *        The lexical environment we want to extract.
+ * @param TargetActor targetActor
+ *        The Target Actor to use as parent actor.
+ * @return The EnvironmentActor for |environment| or |undefined| for host
+ *         functions or functions scoped to a non-debuggee global.
+ */
+function createEnvironmentActor(environment, targetActor) {
+  if (!environment) {
+    return undefined;
+  }
+
+  if (environment.actor) {
+    return environment.actor;
+  }
+
+  const actor = new EnvironmentActor(environment, targetActor);
+  targetActor.manage(actor);
+  environment.actor = actor;
+
+  return actor;
+}
+
+/**
+ * Create a grip for the given object.
+ *
+ * @param TargetActor targetActor
+ *        The Target Actor from which this object originates.
+ * @param Number depth
+ *        Depth of the object compared to the top level object,
+ *        when we are inspecting nested attributes.
+ * @param object object
+ *        The object you want.
+ * @param object pool
+ *        A Pool where the new actor instance is added.
+ * @param object
+ *        The object grip.
+ */
+function createObjectGrip(targetActor, depth, object, pool) {
+  let gripDepth = depth;
+  const actor = new ObjectActor(
+    object,
+    {
+      thread: targetActor.threadActor,
+      getGripDepth: () => gripDepth,
+      incrementGripDepth: () => gripDepth++,
+      decrementGripDepth: () => gripDepth--,
+      createValueGrip: v => createValueGripForTarget(targetActor, v, gripDepth),
+      createEnvironmentActor: env => createEnvironmentActor(env, targetActor),
+    },
+    targetActor.conn
+  );
+  pool.manage(actor);
+  return actor.form();
+}
+
+module.exports = {
+  getPromiseState,
+  makeDebuggeeValueIfNeeded,
+  unwrapDebuggeeValue,
+  createValueGrip,
+  stringIsLong,
+  isTypedArray,
+  isArray,
+  isStorage,
+  getArrayLength,
+  getStorageLength,
+  isArrayIndex,
+  getPropsForEvent,
+  getPropNamesFromObject,
+  getSafeOwnPropertySymbols,
+  getSafePrivatePropertiesSymbols,
+  getModifiersForEvent,
+  isObjectOrFunction,
+  createStringGrip,
+  makeDebuggeeValue,
+  createValueGripForTarget,
+};