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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/* 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, {
EventEmitter: "resource://gre/modules/EventEmitter.sys.mjs",
getFramesFromStack: "chrome://remote/content/shared/Stack.sys.mjs",
Log: "chrome://remote/content/shared/Log.sys.mjs",
});
ChromeUtils.defineLazyGetter(lazy, "logger", () => lazy.Log.get());
/**
* The ConsoleListener can be used to listen for console messages related to
* Javascript errors, certain warnings which all happen within a specific
* windowGlobal. Consumers can listen for the message types "error",
* "warn" and "info".
*
* Example:
* ```
* const onJavascriptError = (eventName, data = {}) => {
* const { level, message, stacktrace, timestamp } = data;
* ...
* };
*
* const listener = new ConsoleListener(innerWindowId);
* listener.on("error", onJavascriptError);
* listener.startListening();
* ...
* listener.stopListening();
* ```
*
* @fires message
* The ConsoleListener emits "error", "warn" and "info" events, with the
* following object as payload:
* - {String} level - Importance, one of `info`, `warn`, `error`,
* `debug`, `trace`.
* - {String} message - Actual message from the console entry.
* - {Array<StackFrame>} stacktrace - List of stack frames,
* starting from most recent.
* - {Number} timeStamp - Timestamp when the method was called.
*/
export class ConsoleListener {
#emittedMessages;
#innerWindowId;
#listening;
/**
* Create a new ConsoleListener instance.
*
* @param {number} innerWindowId
* The inner window id to filter the messages for.
*/
constructor(innerWindowId) {
lazy.EventEmitter.decorate(this);
this.#emittedMessages = new Set();
this.#innerWindowId = innerWindowId;
this.#listening = false;
}
get listening() {
return this.#listening;
}
destroy() {
this.stopListening();
this.#emittedMessages = null;
}
startListening() {
if (this.#listening) {
return;
}
Services.console.registerListener(this.#onConsoleMessage);
// Emit cached messages after registering the listener, to make sure we
// don't miss any message.
this.#emitCachedMessages();
this.#listening = true;
}
stopListening() {
if (!this.#listening) {
return;
}
Services.console.unregisterListener(this.#onConsoleMessage);
this.#listening = false;
}
#emitCachedMessages() {
const cachedMessages = Services.console.getMessageArray() || [];
for (const message of cachedMessages) {
this.#onConsoleMessage(message);
}
}
#onConsoleMessage = message => {
if (!(message instanceof Ci.nsIScriptError)) {
// For now ignore basic nsIConsoleMessage instances, which are only
// relevant to Chrome code and do not have a valid window reference.
return;
}
// Bail if this message was already emitted, useful to filter out cached
// messages already received by the consumer.
if (this.#emittedMessages.has(message)) {
return;
}
this.#emittedMessages.add(message);
if (message.innerWindowID !== this.#innerWindowId) {
// If the message doesn't match the innerWindowId of the current context
// ignore it.
return;
}
const { errorFlag, warningFlag, infoFlag } = Ci.nsIScriptError;
let level;
if ((message.flags & warningFlag) == warningFlag) {
level = "warn";
} else if ((message.flags & infoFlag) == infoFlag) {
level = "info";
} else if ((message.flags & errorFlag) == errorFlag) {
level = "error";
} else {
lazy.logger.warn(
`Not able to process console message with unknown flags ${message.flags}`
);
return;
}
// Send event when actively listening.
this.emit(level, {
level,
message: message.errorMessage,
stacktrace: lazy.getFramesFromStack(message.stack),
timeStamp: message.timeStamp,
});
};
get QueryInterface() {
return ChromeUtils.generateQI(["nsIConsoleListener"]);
}
}
|
