tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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Errors.sys.mjs (2572B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
      3 * You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 import { RemoteError } from "chrome://remote/content/shared/RemoteError.sys.mjs";
      6 
      7 class MessageHandlerError extends RemoteError {
      8  /**
      9   * @param {(string|Error)=} x
     10   *     Optional string describing error situation or Error instance
     11   *     to propagate.
     12   */
     13  constructor(x) {
     14    super(x);
     15    this.name = this.constructor.name;
     16    this.status = "message handler error";
     17 
     18    // Error's ctor does not preserve x' stack
     19    if (typeof x?.stack !== "undefined") {
     20      this.stack = x.stack;
     21    }
     22  }
     23 
     24  get isMessageHandlerError() {
     25    return true;
     26  }
     27 
     28  /**
     29   * @returns {Record<string, string>}
     30   *     JSON serialisation of error prototype.
     31   */
     32  toJSON() {
     33    return {
     34      error: this.status,
     35      message: this.message || "",
     36      stacktrace: this.stack || "",
     37    };
     38  }
     39 
     40  /**
     41   * Unmarshals a JSON error representation to the appropriate MessageHandler
     42   * error type.
     43   *
     44   * @param {Record<string, string>} json
     45   *     Error object.
     46   *
     47   * @returns {Error}
     48   *     Error prototype.
     49   */
     50  static fromJSON(json) {
     51    if (typeof json.error == "undefined") {
     52      let s = JSON.stringify(json);
     53      throw new TypeError("Undeserialisable error type: " + s);
     54    }
     55    if (!STATUSES.has(json.error)) {
     56      throw new TypeError("Not of MessageHandlerError descent: " + json.error);
     57    }
     58 
     59    let cls = STATUSES.get(json.error);
     60    let err = new cls();
     61    if ("message" in json) {
     62      err.message = json.message;
     63    }
     64    if ("stacktrace" in json) {
     65      err.stack = json.stacktrace;
     66    }
     67    return err;
     68  }
     69 }
     70 
     71 /**
     72 * A browsing context is no longer available.
     73 */
     74 class DiscardedBrowsingContextError extends MessageHandlerError {
     75  constructor(message) {
     76    super(message);
     77    this.status = `discarded browsing context`;
     78  }
     79 }
     80 
     81 /**
     82 * A command could not be handled by the message handler network.
     83 */
     84 class UnsupportedCommandError extends MessageHandlerError {
     85  constructor(message) {
     86    super(message);
     87    this.status = "unsupported message handler command";
     88  }
     89 }
     90 
     91 const STATUSES = new Map([
     92  ["discarded browsing context", DiscardedBrowsingContextError],
     93  ["message handler error", MessageHandlerError],
     94  ["unsupported message handler command", UnsupportedCommandError],
     95 ]);
     96 
     97 /** @namespace */
     98 export const error = {
     99  DiscardedBrowsingContextError,
    100  MessageHandlerError,
    101  UnsupportedCommandError,
    102 };