gecko-dev/remote/Error.jsm

138 строки
3.5 KiB
JavaScript

/* 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";
var EXPORTED_SYMBOLS = [
"FatalError",
"RemoteAgentError",
"UnknownMethodError",
"UnsupportedError",
];
const { Log } = ChromeUtils.import("chrome://remote/content/Log.jsm");
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
const { XPCOMUtils } = ChromeUtils.import(
"resource://gre/modules/XPCOMUtils.jsm"
);
XPCOMUtils.defineLazyGetter(this, "log", Log.get);
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() {
Cu.reportError(this);
log.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/sessions/Session.jsm:73:39\n
* onMessage@chrome://remote/content/sessions/TabSession.jsm: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.
*
* @return {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.
*/
class FatalError extends RemoteAgentError {
constructor(...args) {
super(...args);
this.quit();
}
notify() {
log.fatal(this.toString({ stack: true }));
}
quit(mode = Ci.nsIAppStartup.eForceQuit) {
Services.startup.quit(mode);
}
}
/** When an operation is not yet implemented. */
class UnsupportedError extends RemoteAgentError {}
/** The requested remote method does not exist. */
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("");
}