angular-docs-cn/packages/zone.js/lib/common/error-rewrite.ts

380 lines
15 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
/**
* @fileoverview
* @suppress {globalThis,undefinedVars}
*/
/**
* Extend the Error with additional fields for rewritten stack frames
*/
interface Error {
/**
* Stack trace where extra frames have been removed and zone names added.
*/
zoneAwareStack?: string;
/**
* Original stack trace with no modifications
*/
originalStack?: string;
}
Zone.__load_patch('Error', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
/*
* This code patches Error so that:
* - It ignores un-needed stack frames.
* - It Shows the associated Zone for reach frame.
*/
const enum FrameType {
/// Skip this frame when printing out stack
blackList,
/// This frame marks zone transition
transition
}
const blacklistedStackFramesSymbol = api.symbol('blacklistedStackFrames');
const NativeError = global[api.symbol('Error')] = global['Error'];
// Store the frames which should be removed from the stack frames
const blackListedStackFrames: {[frame: string]: FrameType} = {};
// We must find the frame where Error was created, otherwise we assume we don't understand stack
let zoneAwareFrame1: string;
let zoneAwareFrame2: string;
let zoneAwareFrame1WithoutNew: string;
let zoneAwareFrame2WithoutNew: string;
let zoneAwareFrame3WithoutNew: string;
global['Error'] = ZoneAwareError;
const stackRewrite = 'stackRewrite';
type BlackListedStackFramesPolicy = 'default' | 'disable' | 'lazy';
const blackListedStackFramesPolicy: BlackListedStackFramesPolicy =
global['__Zone_Error_BlacklistedStackFrames_policy'] || 'default';
interface ZoneFrameName {
zoneName: string;
parent?: ZoneFrameName;
}
function buildZoneFrameNames(zoneFrame: _ZoneFrame) {
let zoneFrameName: ZoneFrameName = {zoneName: zoneFrame.zone.name};
let result = zoneFrameName;
while (zoneFrame.parent) {
zoneFrame = zoneFrame.parent;
const parentZoneFrameName = {zoneName: zoneFrame.zone.name};
zoneFrameName.parent = parentZoneFrameName;
zoneFrameName = parentZoneFrameName;
}
return result;
}
function buildZoneAwareStackFrames(
originalStack: string, zoneFrame: _ZoneFrame | ZoneFrameName | null, isZoneFrame = true) {
let frames: string[] = originalStack.split('\n');
let i = 0;
// Find the first frame
while (!(frames[i] === zoneAwareFrame1 || frames[i] === zoneAwareFrame2 ||
frames[i] === zoneAwareFrame1WithoutNew || frames[i] === zoneAwareFrame2WithoutNew ||
frames[i] === zoneAwareFrame3WithoutNew) &&
i < frames.length) {
i++;
}
for (; i < frames.length && zoneFrame; i++) {
let frame = frames[i];
if (frame.trim()) {
switch (blackListedStackFrames[frame]) {
case FrameType.blackList:
frames.splice(i, 1);
i--;
break;
case FrameType.transition:
if (zoneFrame.parent) {
// This is the special frame where zone changed. Print and process it accordingly
zoneFrame = zoneFrame.parent;
} else {
zoneFrame = null;
}
frames.splice(i, 1);
i--;
break;
default:
frames[i] += isZoneFrame ? ` [${(zoneFrame as _ZoneFrame).zone.name}]` :
` [${(zoneFrame as ZoneFrameName).zoneName}]`;
}
}
}
return frames.join('\n');
}
/**
* This is ZoneAwareError which processes the stack frame and cleans up extra frames as well as
* adds zone information to it.
*/
function ZoneAwareError(this: unknown | typeof NativeError): Error {
// We always have to return native error otherwise the browser console will not work.
let error: Error = NativeError.apply(this, arguments);
// Save original stack trace
const originalStack = (error as any)['originalStack'] = error.stack;
// Process the stack trace and rewrite the frames.
if ((ZoneAwareError as any)[stackRewrite] && originalStack) {
let zoneFrame = api.currentZoneFrame();
if (blackListedStackFramesPolicy === 'lazy') {
// don't handle stack trace now
(error as any)[api.symbol('zoneFrameNames')] = buildZoneFrameNames(zoneFrame);
} else if (blackListedStackFramesPolicy === 'default') {
try {
error.stack = error.zoneAwareStack = buildZoneAwareStackFrames(originalStack, zoneFrame);
} catch (e) {
// ignore as some browsers don't allow overriding of stack
}
}
}
if (this instanceof NativeError && this.constructor != NativeError) {
// We got called with a `new` operator AND we are subclass of ZoneAwareError
// in that case we have to copy all of our properties to `this`.
Object.keys(error).concat('stack', 'message').forEach((key) => {
const value = (error as any)[key];
if (value !== undefined) {
try {
this[key] = value;
} catch (e) {
// ignore the assignment in case it is a setter and it throws.
}
}
});
return this;
}
return error;
}
// Copy the prototype so that instanceof operator works as expected
ZoneAwareError.prototype = NativeError.prototype;
(ZoneAwareError as any)[blacklistedStackFramesSymbol] = blackListedStackFrames;
(ZoneAwareError as any)[stackRewrite] = false;
const zoneAwareStackSymbol = api.symbol('zoneAwareStack');
// try to define zoneAwareStack property when blackListed
// policy is delay
if (blackListedStackFramesPolicy === 'lazy') {
Object.defineProperty(ZoneAwareError.prototype, 'zoneAwareStack', {
configurable: true,
enumerable: true,
get: function() {
if (!this[zoneAwareStackSymbol]) {
this[zoneAwareStackSymbol] = buildZoneAwareStackFrames(
this.originalStack, this[api.symbol('zoneFrameNames')], false);
}
return this[zoneAwareStackSymbol];
},
set: function(newStack: string) {
this.originalStack = newStack;
this[zoneAwareStackSymbol] = buildZoneAwareStackFrames(
this.originalStack, this[api.symbol('zoneFrameNames')], false);
}
});
}
// those properties need special handling
const specialPropertyNames = ['stackTraceLimit', 'captureStackTrace', 'prepareStackTrace'];
// those properties of NativeError should be set to ZoneAwareError
const nativeErrorProperties = Object.keys(NativeError);
if (nativeErrorProperties) {
nativeErrorProperties.forEach(prop => {
if (specialPropertyNames.filter(sp => sp === prop).length === 0) {
Object.defineProperty(ZoneAwareError, prop, {
get: function() { return NativeError[prop]; },
set: function(value) { NativeError[prop] = value; }
});
}
});
}
if (NativeError.hasOwnProperty('stackTraceLimit')) {
// Extend default stack limit as we will be removing few frames.
NativeError.stackTraceLimit = Math.max(NativeError.stackTraceLimit, 15);
// make sure that ZoneAwareError has the same property which forwards to NativeError.
Object.defineProperty(ZoneAwareError, 'stackTraceLimit', {
get: function() { return NativeError.stackTraceLimit; },
set: function(value) { return NativeError.stackTraceLimit = value; }
});
}
if (NativeError.hasOwnProperty('captureStackTrace')) {
Object.defineProperty(ZoneAwareError, 'captureStackTrace', {
// add named function here because we need to remove this
// stack frame when prepareStackTrace below
value: function zoneCaptureStackTrace(targetObject: Object, constructorOpt?: Function) {
NativeError.captureStackTrace(targetObject, constructorOpt);
}
});
}
const ZONE_CAPTURESTACKTRACE = 'zoneCaptureStackTrace';
Object.defineProperty(ZoneAwareError, 'prepareStackTrace', {
get: function() { return NativeError.prepareStackTrace; },
set: function(value) {
if (!value || typeof value !== 'function') {
return NativeError.prepareStackTrace = value;
}
return NativeError.prepareStackTrace = function(
error: Error, structuredStackTrace: {getFunctionName: Function}[]) {
// remove additional stack information from ZoneAwareError.captureStackTrace
if (structuredStackTrace) {
for (let i = 0; i < structuredStackTrace.length; i++) {
const st = structuredStackTrace[i];
// remove the first function which name is zoneCaptureStackTrace
if (st.getFunctionName() === ZONE_CAPTURESTACKTRACE) {
structuredStackTrace.splice(i, 1);
break;
}
}
}
return value.call(this, error, structuredStackTrace);
};
}
});
if (blackListedStackFramesPolicy === 'disable') {
// don't need to run detectZone to populate
// blacklisted stack frames
return;
}
// Now we need to populate the `blacklistedStackFrames` as well as find the
// run/runGuarded/runTask frames. This is done by creating a detect zone and then threading
// the execution through all of the above methods so that we can look at the stack trace and
// find the frames of interest.
let detectZone: Zone = Zone.current.fork({
name: 'detect',
onHandleError: function(
parentZD: ZoneDelegate, current: Zone, target: Zone, error: any): boolean {
if (error.originalStack && Error === ZoneAwareError) {
let frames = error.originalStack.split(/\n/);
let runFrame = false, runGuardedFrame = false, runTaskFrame = false;
while (frames.length) {
let frame = frames.shift();
// On safari it is possible to have stack frame with no line number.
// This check makes sure that we don't filter frames on name only (must have
// line number or exact equals to `ZoneAwareError`)
if (/:\d+:\d+/.test(frame) || frame === 'ZoneAwareError') {
// Get rid of the path so that we don't accidentally find function name in path.
// In chrome the separator is `(` and `@` in FF and safari
// Chrome: at Zone.run (zone.js:100)
// Chrome: at Zone.run (http://localhost:9876/base/build/lib/zone.js:100:24)
// FireFox: Zone.prototype.run@http://localhost:9876/base/build/lib/zone.js:101:24
// Safari: run@http://localhost:9876/base/build/lib/zone.js:101:24
let fnName: string = frame.split('(')[0].split('@')[0];
let frameType = FrameType.transition;
if (fnName.indexOf('ZoneAwareError') !== -1) {
if (fnName.indexOf('new ZoneAwareError') !== -1) {
zoneAwareFrame1 = frame;
zoneAwareFrame2 = frame.replace('new ZoneAwareError', 'new Error.ZoneAwareError');
} else {
zoneAwareFrame1WithoutNew = frame;
zoneAwareFrame2WithoutNew = frame.replace('Error.', '');
if (frame.indexOf('Error.ZoneAwareError') === -1) {
zoneAwareFrame3WithoutNew =
frame.replace('ZoneAwareError', 'Error.ZoneAwareError');
}
}
blackListedStackFrames[zoneAwareFrame2] = FrameType.blackList;
}
if (fnName.indexOf('runGuarded') !== -1) {
runGuardedFrame = true;
} else if (fnName.indexOf('runTask') !== -1) {
runTaskFrame = true;
} else if (fnName.indexOf('run') !== -1) {
runFrame = true;
} else {
frameType = FrameType.blackList;
}
blackListedStackFrames[frame] = frameType;
// Once we find all of the frames we can stop looking.
if (runFrame && runGuardedFrame && runTaskFrame) {
(ZoneAwareError as any)[stackRewrite] = true;
break;
}
}
}
}
return false;
}
}) as Zone;
// carefully constructor a stack frame which contains all of the frames of interest which
// need to be detected and blacklisted.
const childDetectZone = detectZone.fork({
name: 'child',
onScheduleTask: function(delegate, curr, target, task) {
return delegate.scheduleTask(target, task);
},
onInvokeTask: function(delegate, curr, target, task, applyThis, applyArgs) {
return delegate.invokeTask(target, task, applyThis, applyArgs);
},
onCancelTask: function(delegate, curr, target, task) {
return delegate.cancelTask(target, task);
},
onInvoke: function(delegate, curr, target, callback, applyThis, applyArgs, source) {
return delegate.invoke(target, callback, applyThis, applyArgs, source);
}
});
// we need to detect all zone related frames, it will
// exceed default stackTraceLimit, so we set it to
// larger number here, and restore it after detect finish.
// We cast through any so we don't need to depend on nodejs typings.
const originalStackTraceLimit = (Error as any).stackTraceLimit;
(Error as any).stackTraceLimit = 100;
// we schedule event/micro/macro task, and invoke them
// when onSchedule, so we can get all stack traces for
// all kinds of tasks with one error thrown.
childDetectZone.run(() => {
childDetectZone.runGuarded(() => {
const fakeTransitionTo = () => {};
childDetectZone.scheduleEventTask(
blacklistedStackFramesSymbol,
() => {
childDetectZone.scheduleMacroTask(
blacklistedStackFramesSymbol,
() => {
childDetectZone.scheduleMicroTask(
blacklistedStackFramesSymbol, () => { throw new Error(); }, undefined,
(t: Task) => {
(t as any)._transitionTo = fakeTransitionTo;
t.invoke();
});
childDetectZone.scheduleMicroTask(
blacklistedStackFramesSymbol, () => { throw Error(); }, undefined,
(t: Task) => {
(t as any)._transitionTo = fakeTransitionTo;
t.invoke();
});
},
undefined,
(t) => {
(t as any)._transitionTo = fakeTransitionTo;
t.invoke();
},
() => {});
},
undefined,
(t) => {
(t as any)._transitionTo = fakeTransitionTo;
t.invoke();
},
() => {});
});
});
(Error as any).stackTraceLimit = originalStackTraceLimit;
});