summaryrefslogtreecommitdiffstats
path: root/remote/cdp/Error.sys.mjs
blob: 37bd33e2e0d4e8277d51fd3bd21cb280fefc6136 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* 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/. */

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  Log: "chrome://remote/content/shared/Log.sys.mjs",
});

ChromeUtils.defineLazyGetter(lazy, "logger", () =>
  lazy.Log.get(lazy.Log.TYPES.CDP)
);

export class RemoteAgentError extends Error {
  constructor(message = "", cause = undefined) {
    cause = cause || message;
    super(cause);

    this.name = this.constructor.name;
    this.message = message;
    this.cause = cause;

    this.notify();
  }

  notify() {
    console.error(this);
    lazy.logger.error(this.toString({ stack: true }));
  }

  toString({ stack = false } = {}) {
    return RemoteAgentError.format(this, { stack });
  }

  static format(e, { stack = false } = {}) {
    return formatError(e, { stack });
  }

  /**
   * Takes a serialised CDP error and reconstructs it
   * as a RemoteAgentError.
   *
   * The error must be of this form:
   *
   *     {"message": "TypeError: foo is not a function\n
   *     execute@chrome://remote/content/cdp/sessions/Session.sys.mjs:73:39\n
   *     onMessage@chrome://remote/content/cdp/sessions/TabSession.sys.mjs:65:20"}
   *
   * This approach has the notable deficiency that it cannot deal
   * with causes to errors because of the unstructured nature of CDP
   * errors.  A possible future improvement would be to extend the
   * error serialisation to include discrete fields for each data
   * property.
   *
   * @param {object} json
   *     CDP error encoded as a JSON object, which must have a
   *     "message" field, where the first line will make out the error
   *     message and the subsequent lines the stacktrace.
   *
   * @returns {RemoteAgentError}
   */
  static fromJSON(json) {
    const [message, ...stack] = json.message.split("\n");
    const err = new RemoteAgentError();
    err.message = message.slice(0, -1);
    err.stack = stack.map(s => s.trim()).join("\n");
    err.cause = null;
    return err;
  }
}

/**
 * A fatal error that it is not possible to recover from
 * or send back to the client.
 *
 * Constructing this error will force the application to quit.
 */
export class FatalError extends RemoteAgentError {
  constructor(...args) {
    super(...args);
    this.quit();
  }

  notify() {
    lazy.logger.fatal(this.toString({ stack: true }));
  }

  quit(mode = Ci.nsIAppStartup.eForceQuit) {
    Services.startup.quit(mode);
  }
}

/** When an operation is not yet implemented. */
export class UnsupportedError extends RemoteAgentError {}

/** The requested remote method does not exist. */
export class UnknownMethodError extends RemoteAgentError {
  constructor(domain, command = null) {
    if (command) {
      super(`${domain}.${command}`);
    } else {
      super(domain);
    }
  }
}

function formatError(error, { stack = false } = {}) {
  const els = [];

  els.push(error.name);
  if (error.message) {
    els.push(": ");
    els.push(error.message);
  }

  if (stack && error.stack) {
    els.push(":\n");

    const stack = error.stack.trim().split("\n");
    els.push(stack.map(line => `\t${line}`).join("\n"));

    if (error.cause) {
      els.push("\n");
      els.push("caused by: " + formatError(error.cause, { stack }));
    }
  }

  return els.join("");
}