angular-docs-cn/packages/core/test/render3/di_spec.ts

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/**
* @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
*/
import {ChangeDetectorRef, Host, InjectFlags, Injector, Optional, Renderer2, Self, ViewContainerRef} from '@angular/core';
import {createLView, createTView, getOrCreateTNode} from '@angular/core/src/render3/instructions/shared';
import {RenderFlags} from '@angular/core/src/render3/interfaces/definition';
import {ɵɵdefineComponent} from '../../src/render3/definition';
import {bloomAdd, bloomHasToken, bloomHashBitOrFactory as bloomHash, getOrCreateNodeInjectorForNode} from '../../src/render3/di';
import {ɵɵcontainer, ɵɵcontainerRefreshEnd, ɵɵcontainerRefreshStart, ɵɵdefineDirective, ɵɵdirectiveInject, ɵɵelement, ɵɵelementEnd, ɵɵelementStart, ɵɵembeddedViewEnd, ɵɵembeddedViewStart, ɵɵprojection, ɵɵprojectionDef, ɵɵreference, ɵɵselect, ɵɵtext, ɵɵtextBinding, ɵɵtextInterpolate2} from '../../src/render3/index';
import {TNODE} from '../../src/render3/interfaces/injector';
import {TNodeType} from '../../src/render3/interfaces/node';
import {isProceduralRenderer} from '../../src/render3/interfaces/renderer';
import {LViewFlags, TVIEW} from '../../src/render3/interfaces/view';
import {enterView, leaveView} from '../../src/render3/state';
import {ViewRef} from '../../src/render3/view_ref';
import {getRendererFactory2} from './imported_renderer2';
import {ComponentFixture, createComponent, createDirective, getDirectiveOnNode, renderComponent, toHtml} from './render_util';
describe('di', () => {
describe('directive injection', () => {
let log: string[] = [];
class DirB {
value = 'DirB';
constructor() { log.push(this.value); }
static ngDirectiveDef = ɵɵdefineDirective({
selectors: [['', 'dirB', '']],
type: DirB,
factory: () => new DirB(),
inputs: {value: 'value'}
});
}
beforeEach(() => log = []);
/**
* This test needs to be moved to acceptance/di_spec.ts
* when Ivy compiler supports inline views.
*/
it('should inject directives in the correct order in a for loop', () => {
class DirA {
constructor(dir: DirB) { log.push(`DirA (dep: ${dir.value})`); }
static ngDirectiveDef = ɵɵdefineDirective({
selectors: [['', 'dirA', '']],
type: DirA,
factory: () => new DirA(ɵɵdirectiveInject(DirB))
});
}
/**
* % for(let i = 0; i < 3; i++) {
* <div dirA dirB></div>
* % }
*/
const App = createComponent('app', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵcontainer(0);
}
if (rf & RenderFlags.Update) {
ɵɵcontainerRefreshStart(0);
{
for (let i = 0; i < 3; i++) {
if (ɵɵembeddedViewStart(0, 1, 0)) {
ɵɵelement(0, 'div', ['dirA', '', 'dirB', '']);
}
ɵɵembeddedViewEnd();
}
}
ɵɵcontainerRefreshEnd();
}
}, 1, 0, [DirA, DirB]);
new ComponentFixture(App);
expect(log).toEqual(
['DirB', 'DirA (dep: DirB)', 'DirB', 'DirA (dep: DirB)', 'DirB', 'DirA (dep: DirB)']);
});
describe('dependencies in parent views', () => {
class DirA {
injector: Injector;
constructor(public dirB: DirB, public vcr: ViewContainerRef) {
this.injector = vcr.injector;
}
static ngDirectiveDef = ɵɵdefineDirective({
type: DirA,
selectors: [['', 'dirA', '']],
factory:
() => new DirA(ɵɵdirectiveInject(DirB), ɵɵdirectiveInject(ViewContainerRef as any)),
exportAs: ['dirA']
});
}
/**
* This test needs to be moved to acceptance/di_spec.ts
* when Ivy compiler supports inline views.
*/
it('should find dependencies of directives nested deeply in inline views', () => {
/**
* <div dirB>
* % if (!skipContent) {
* % if (!skipContent2) {
* <div dirA #dir="dirA"> {{ dir.dirB.value }} </div>
* % }
* % }
* </div>
*/
const App = createComponent('app', (rf: RenderFlags, ctx: any) => {
if (rf & RenderFlags.Create) {
ɵɵelementStart(0, 'div', ['dirB', '']);
{ ɵɵcontainer(1); }
ɵɵelementEnd();
}
if (rf & RenderFlags.Update) {
ɵɵcontainerRefreshStart(1);
{
if (!ctx.skipContent) {
let rf1 = ɵɵembeddedViewStart(0, 1, 0);
{
if (rf1 & RenderFlags.Create) {
ɵɵcontainer(0);
}
if (rf1 & RenderFlags.Update) {
ɵɵcontainerRefreshStart(0);
{
if (!ctx.skipContent2) {
let rf2 = ɵɵembeddedViewStart(0, 3, 1);
{
if (rf2 & RenderFlags.Create) {
ɵɵelementStart(0, 'div', ['dirA', ''], ['dir', 'dirA']);
{ ɵɵtext(2); }
ɵɵelementEnd();
}
if (rf2 & RenderFlags.Update) {
const dir = ɵɵreference(1) as DirA;
ɵɵselect(2);
ɵɵtextBinding(dir.dirB.value);
}
}
ɵɵembeddedViewEnd();
}
}
ɵɵcontainerRefreshEnd();
}
}
ɵɵembeddedViewEnd();
}
}
ɵɵcontainerRefreshEnd();
}
}, 2, 0, [DirA, DirB]);
const fixture = new ComponentFixture(App);
expect(fixture.hostElement.textContent).toEqual(`DirB`);
});
});
describe('flags', () => {
class DirB {
// TODO(issue/24571): remove '!'.
value !: string;
static ngDirectiveDef = ɵɵdefineDirective({
type: DirB,
selectors: [['', 'dirB', '']],
factory: () => new DirB(),
inputs: {value: 'dirB'}
});
}
describe('Optional', () => {
let dirA: DirA|null = null;
class DirA {
constructor(@Optional() public dirB: DirB|null) {}
static ngDirectiveDef = ɵɵdefineDirective({
type: DirA,
selectors: [['', 'dirA', '']],
factory: () => dirA = new DirA(ɵɵdirectiveInject(DirB, InjectFlags.Optional))
});
}
beforeEach(() => dirA = null);
it('should not throw if dependency is @Optional (limp mode)', () => {
/** <div dirA></div> */
const App = createComponent('app', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵelement(0, 'div', ['dirA', '']);
}
}, 1, 0, [DirA, DirB]);
expect(() => { new ComponentFixture(App); }).not.toThrow();
expect(dirA !.dirB).toEqual(null);
});
});
it('should check only the current node with @Self even with false positive', () => {
let dirA: DirA;
class DirA {
constructor(@Self() public dirB: DirB) {}
static ngDirectiveDef = ɵɵdefineDirective({
type: DirA,
selectors: [['', 'dirA', '']],
factory: () => dirA = new DirA(ɵɵdirectiveInject(DirB, InjectFlags.Self))
});
}
const DirC = createDirective('dirC');
/**
* <div dirB>
* <div dirA dirC></div>
* </div>
*/
const App = createComponent('app', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵelementStart(0, 'div', ['dirB', '']);
ɵɵelement(1, 'div', ['dirA', '', 'dirC', '']);
ɵɵelementEnd();
}
}, 2, 0, [DirA, DirB, DirC]);
expect(() => {
(DirA as any)['__NG_ELEMENT_ID__'] = 1;
(DirC as any)['__NG_ELEMENT_ID__'] = 257;
new ComponentFixture(App);
}).toThrowError(/NodeInjector: NOT_FOUND \[DirB\]/);
});
describe('@Host', () => {
let dirA: DirA|null = null;
beforeEach(() => { dirA = null; });
class DirA {
constructor(@Host() public dirB: DirB) {}
static ngDirectiveDef = ɵɵdefineDirective({
type: DirA,
selectors: [['', 'dirA', '']],
factory: () => dirA = new DirA(ɵɵdirectiveInject(DirB, InjectFlags.Host))
});
}
/**
* This test needs to be moved to acceptance/di_spec.ts
* when Ivy compiler supports inline views.
*/
it('should not find providers on the host itself if in inline view', () => {
let comp !: any;
/**
* % if (showing) {
* <div dirA></div>
* % }
*/
const Comp = createComponent('comp', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵcontainer(0);
}
if (rf & RenderFlags.Update) {
ɵɵcontainerRefreshStart(0);
{
if (ctx.showing) {
let rf1 = ɵɵembeddedViewStart(0, 1, 0);
if (rf1 & RenderFlags.Create) {
ɵɵelement(0, 'div', ['dirA', '']);
}
ɵɵembeddedViewEnd();
}
}
ɵɵcontainerRefreshEnd();
}
}, 1, 0, [DirA, DirB]);
/* <comp dirB></comp> */
const App = createComponent('app', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵelement(0, 'comp', ['dirB', '']);
}
if (rf & RenderFlags.Update) {
comp = getDirectiveOnNode(0);
}
}, 1, 0, [Comp, DirB]);
const fixture = new ComponentFixture(App);
expect(() => {
comp.showing = true;
fixture.update();
}).toThrowError(/NodeInjector: NOT_FOUND \[DirB\]/);
});
});
});
});
describe('Special tokens', () => {
describe('ChangeDetectorRef', () => {
let dir: Directive;
let dirSameInstance: DirectiveSameInstance;
let comp: MyComp;
class MyComp {
constructor(public cdr: ChangeDetectorRef) {}
static ngComponentDef = ɵɵdefineComponent({
type: MyComp,
selectors: [['my-comp']],
factory: () => comp = new MyComp(ɵɵdirectiveInject(ChangeDetectorRef as any)),
consts: 1,
vars: 0,
template: function(rf: RenderFlags, ctx: MyComp) {
if (rf & RenderFlags.Create) {
ɵɵprojectionDef();
ɵɵprojection(0);
}
}
});
}
class Directive {
value: string;
constructor(public cdr: ChangeDetectorRef) { this.value = (cdr.constructor as any).name; }
static ngDirectiveDef = ɵɵdefineDirective({
type: Directive,
selectors: [['', 'dir', '']],
factory: () => dir = new Directive(ɵɵdirectiveInject(ChangeDetectorRef as any)),
exportAs: ['dir']
});
}
class DirectiveSameInstance {
constructor(public cdr: ChangeDetectorRef) {}
static ngDirectiveDef = ɵɵdefineDirective({
type: DirectiveSameInstance,
selectors: [['', 'dirSame', '']],
factory: () => dirSameInstance =
new DirectiveSameInstance(ɵɵdirectiveInject(ChangeDetectorRef as any))
});
}
const directives = [MyComp, Directive, DirectiveSameInstance];
/**
* This test needs to be moved to acceptance/di_spec.ts
* when Ivy compiler supports inline views.
*/
it('should inject host component ChangeDetectorRef into directives in embedded views', () => {
class MyApp {
showing = true;
constructor(public cdr: ChangeDetectorRef) {}
static ngComponentDef = ɵɵdefineComponent({
type: MyApp,
selectors: [['my-app']],
factory: () => new MyApp(ɵɵdirectiveInject(ChangeDetectorRef as any)),
consts: 1,
vars: 0,
/**
* % if (showing) {
* <div dir dirSame #dir="dir"> {{ dir.value }} </div>
* % }
*/
template: function(rf: RenderFlags, ctx: MyApp) {
if (rf & RenderFlags.Create) {
ɵɵcontainer(0);
}
if (rf & RenderFlags.Update) {
ɵɵcontainerRefreshStart(0);
{
if (ctx.showing) {
let rf1 = ɵɵembeddedViewStart(0, 3, 1);
if (rf1 & RenderFlags.Create) {
ɵɵelementStart(0, 'div', ['dir', '', 'dirSame', ''], ['dir', 'dir']);
{ ɵɵtext(2); }
ɵɵelementEnd();
}
if (rf1 & RenderFlags.Update) {
const tmp = ɵɵreference(1) as any;
ɵɵselect(2);
ɵɵtextBinding(tmp.value);
}
}
ɵɵembeddedViewEnd();
}
ɵɵcontainerRefreshEnd();
}
},
directives: directives
});
}
const app = renderComponent(MyApp);
expect(toHtml(app)).toEqual('<div dir="" dirsame="">ViewRef</div>');
expect((app !.cdr as ViewRef<MyApp>).context).toBe(app);
// Each ChangeDetectorRef instance should be unique
expect(dir !.cdr).not.toBe(app.cdr);
expect(dir !.cdr).not.toBe(dirSameInstance !.cdr);
});
});
});
describe('Renderer2', () => {
class MyComp {
constructor(public renderer: Renderer2) {}
static ngComponentDef = ɵɵdefineComponent({
type: MyComp,
selectors: [['my-comp']],
factory: () => new MyComp(ɵɵdirectiveInject(Renderer2 as any)),
consts: 1,
vars: 0,
template: function(rf: RenderFlags, ctx: MyComp) {
if (rf & RenderFlags.Create) {
ɵɵtext(0, 'Foo');
}
}
});
}
it('should inject the Renderer2 used by the application', () => {
const rendererFactory = getRendererFactory2(document);
const fixture = new ComponentFixture(MyComp, {rendererFactory: rendererFactory});
expect(isProceduralRenderer(fixture.component.renderer)).toBeTruthy();
});
it('should throw when injecting Renderer2 but the application is using Renderer3',
() => { expect(() => new ComponentFixture(MyComp)).toThrow(); });
});
describe('ɵɵinject', () => {
describe('bloom filter', () => {
let mockTView: any;
beforeEach(() => {
mockTView = {data: [0, 0, 0, 0, 0, 0, 0, 0, null], firstTemplatePass: true};
});
function bloomState() { return mockTView.data.slice(0, TNODE).reverse(); }
class Dir0 {
/** @internal */ static __NG_ELEMENT_ID__ = 0;
}
class Dir1 {
/** @internal */ static __NG_ELEMENT_ID__ = 1;
}
class Dir33 {
/** @internal */ static __NG_ELEMENT_ID__ = 33;
}
class Dir66 {
/** @internal */ static __NG_ELEMENT_ID__ = 66;
}
class Dir99 {
/** @internal */ static __NG_ELEMENT_ID__ = 99;
}
class Dir132 {
/** @internal */ static __NG_ELEMENT_ID__ = 132;
}
class Dir165 {
/** @internal */ static __NG_ELEMENT_ID__ = 165;
}
class Dir198 {
/** @internal */ static __NG_ELEMENT_ID__ = 198;
}
class Dir231 {
/** @internal */ static __NG_ELEMENT_ID__ = 231;
}
it('should add values', () => {
bloomAdd(0, mockTView, Dir0);
expect(bloomState()).toEqual([0, 0, 0, 0, 0, 0, 0, 1]);
bloomAdd(0, mockTView, Dir33);
expect(bloomState()).toEqual([0, 0, 0, 0, 0, 0, 2, 1]);
bloomAdd(0, mockTView, Dir66);
expect(bloomState()).toEqual([0, 0, 0, 0, 0, 4, 2, 1]);
bloomAdd(0, mockTView, Dir99);
expect(bloomState()).toEqual([0, 0, 0, 0, 8, 4, 2, 1]);
bloomAdd(0, mockTView, Dir132);
expect(bloomState()).toEqual([0, 0, 0, 16, 8, 4, 2, 1]);
bloomAdd(0, mockTView, Dir165);
expect(bloomState()).toEqual([0, 0, 32, 16, 8, 4, 2, 1]);
bloomAdd(0, mockTView, Dir198);
expect(bloomState()).toEqual([0, 64, 32, 16, 8, 4, 2, 1]);
bloomAdd(0, mockTView, Dir231);
expect(bloomState()).toEqual([128, 64, 32, 16, 8, 4, 2, 1]);
});
it('should query values', () => {
bloomAdd(0, mockTView, Dir0);
bloomAdd(0, mockTView, Dir33);
bloomAdd(0, mockTView, Dir66);
bloomAdd(0, mockTView, Dir99);
bloomAdd(0, mockTView, Dir132);
bloomAdd(0, mockTView, Dir165);
bloomAdd(0, mockTView, Dir198);
bloomAdd(0, mockTView, Dir231);
expect(bloomHasToken(bloomHash(Dir0) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir1) as number, 0, mockTView.data)).toEqual(false);
expect(bloomHasToken(bloomHash(Dir33) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir66) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir99) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir132) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir165) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir198) as number, 0, mockTView.data)).toEqual(true);
expect(bloomHasToken(bloomHash(Dir231) as number, 0, mockTView.data)).toEqual(true);
});
});
/**
* This test needs to be moved to acceptance/di_spec.ts when Ivy compiler supports inline views.
*/
it('should inject from parent view', () => {
const ParentDirective = createDirective('parentDir');
class ChildDirective {
value: string;
constructor(public parent: any) { this.value = (parent.constructor as any).name; }
static ngDirectiveDef = ɵɵdefineDirective({
type: ChildDirective,
selectors: [['', 'childDir', '']],
factory: () => new ChildDirective(ɵɵdirectiveInject(ParentDirective)),
exportAs: ['childDir']
});
}
class Child2Directive {
value: boolean;
constructor(parent: any, child: ChildDirective) { this.value = parent === child.parent; }
static ngDirectiveDef = ɵɵdefineDirective({
selectors: [['', 'child2Dir', '']],
type: Child2Directive,
factory: () => new Child2Directive(
ɵɵdirectiveInject(ParentDirective), ɵɵdirectiveInject(ChildDirective)),
exportAs: ['child2Dir']
});
}
/**
* <div parentDir>
* % if (...) {
* <span childDir child2Dir #child1="childDir" #child2="child2Dir">
* {{ child1.value }} - {{ child2.value }}
* </span>
* % }
* </div>
*/
const App = createComponent('app', function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵelementStart(0, 'div', ['parentDir', '']);
{ ɵɵcontainer(1); }
ɵɵelementEnd();
}
if (rf & RenderFlags.Update) {
ɵɵcontainerRefreshStart(1);
{
let rf1 = ɵɵembeddedViewStart(0, 4, 2);
if (rf1 & RenderFlags.Create) {
ɵɵelementStart(
0, 'span', ['childDir', '', 'child2Dir', ''],
['child1', 'childDir', 'child2', 'child2Dir']);
{ ɵɵtext(3); }
ɵɵelementEnd();
}
if (rf & RenderFlags.Update) {
const tmp1 = ɵɵreference(1) as any;
const tmp2 = ɵɵreference(2) as any;
ɵɵselect(3);
ɵɵtextInterpolate2('', tmp1.value, '-', tmp2.value, '');
}
ɵɵembeddedViewEnd();
}
ɵɵcontainerRefreshEnd();
}
}, 2, 0, [ChildDirective, Child2Directive, ParentDirective]);
const fixture = new ComponentFixture(App);
expect(fixture.html)
.toEqual('<div parentdir=""><span child2dir="" childdir="">Directive-true</span></div>');
});
});
describe('getOrCreateNodeInjector', () => {
it('should handle initial undefined state', () => {
const contentView = createLView(
null, createTView(-1, null, 1, 0, null, null, null, null), null, LViewFlags.CheckAlways,
null, null, {} as any, {} as any);
const oldView = enterView(contentView, null);
fix(ivy): don't mask errors by calling lifecycle hooks after a crash (#31244) The Angular runtime frequently calls into user code (for example, when writing to a property binding). Since user code can throw errors, calls to it are frequently wrapped in a try-finally block. In Ivy, the following pattern is common: ```typescript enterView(); try { callUserCode(); } finally { leaveView(); } ``` This has a significant problem, however: `leaveView` has a side effect: it calls any pending lifecycle hooks that might've been scheduled during the current round of change detection. Generally it's a bad idea to run lifecycle hooks after the application has crashed. The application is in an inconsistent state - directives may not be instantiated fully, queries may not be resolved, bindings may not have been applied, etc. Invariants that the app code relies upon may not hold. Further crashes or broken behavior are likely. Frequently, lifecycle hooks are used to make assertions about these invariants. When these assertions fail, they will throw and "swallow" the original error, making debugging of the problem much more difficult. This commit modifies `leaveView` to understand whether the application is currently crashing, via a parameter `safeToRunHooks`. This parameter is set by modifying the above pattern: ```typescript enterView(); let safeToRunHooks = false; try { callUserCode(); safeToRunHooks = true; } finally { leaveView(..., safeToRunHooks); } ``` If `callUserCode` crashes, then `safeToRunHooks` will never be set to `true` and `leaveView` won't call any further user code. The original error will then propagate back up the stack and be reported correctly. A test is added to verify this behavior. PR Close #31244
2019-06-24 16:14:05 -04:00
let safeToRunHooks = false;
try {
const parentTNode =
getOrCreateTNode(contentView[TVIEW], null, 0, TNodeType.Element, null, null);
// Simulate the situation where the previous parent is not initialized.
// This happens on first bootstrap because we don't init existing values
// so that we have smaller HelloWorld.
(parentTNode as{parent: any}).parent = undefined;
const injector = getOrCreateNodeInjectorForNode(parentTNode, contentView);
expect(injector).not.toEqual(-1);
fix(ivy): don't mask errors by calling lifecycle hooks after a crash (#31244) The Angular runtime frequently calls into user code (for example, when writing to a property binding). Since user code can throw errors, calls to it are frequently wrapped in a try-finally block. In Ivy, the following pattern is common: ```typescript enterView(); try { callUserCode(); } finally { leaveView(); } ``` This has a significant problem, however: `leaveView` has a side effect: it calls any pending lifecycle hooks that might've been scheduled during the current round of change detection. Generally it's a bad idea to run lifecycle hooks after the application has crashed. The application is in an inconsistent state - directives may not be instantiated fully, queries may not be resolved, bindings may not have been applied, etc. Invariants that the app code relies upon may not hold. Further crashes or broken behavior are likely. Frequently, lifecycle hooks are used to make assertions about these invariants. When these assertions fail, they will throw and "swallow" the original error, making debugging of the problem much more difficult. This commit modifies `leaveView` to understand whether the application is currently crashing, via a parameter `safeToRunHooks`. This parameter is set by modifying the above pattern: ```typescript enterView(); let safeToRunHooks = false; try { callUserCode(); safeToRunHooks = true; } finally { leaveView(..., safeToRunHooks); } ``` If `callUserCode` crashes, then `safeToRunHooks` will never be set to `true` and `leaveView` won't call any further user code. The original error will then propagate back up the stack and be reported correctly. A test is added to verify this behavior. PR Close #31244
2019-06-24 16:14:05 -04:00
safeToRunHooks = true;
} finally {
fix(ivy): don't mask errors by calling lifecycle hooks after a crash (#31244) The Angular runtime frequently calls into user code (for example, when writing to a property binding). Since user code can throw errors, calls to it are frequently wrapped in a try-finally block. In Ivy, the following pattern is common: ```typescript enterView(); try { callUserCode(); } finally { leaveView(); } ``` This has a significant problem, however: `leaveView` has a side effect: it calls any pending lifecycle hooks that might've been scheduled during the current round of change detection. Generally it's a bad idea to run lifecycle hooks after the application has crashed. The application is in an inconsistent state - directives may not be instantiated fully, queries may not be resolved, bindings may not have been applied, etc. Invariants that the app code relies upon may not hold. Further crashes or broken behavior are likely. Frequently, lifecycle hooks are used to make assertions about these invariants. When these assertions fail, they will throw and "swallow" the original error, making debugging of the problem much more difficult. This commit modifies `leaveView` to understand whether the application is currently crashing, via a parameter `safeToRunHooks`. This parameter is set by modifying the above pattern: ```typescript enterView(); let safeToRunHooks = false; try { callUserCode(); safeToRunHooks = true; } finally { leaveView(..., safeToRunHooks); } ``` If `callUserCode` crashes, then `safeToRunHooks` will never be set to `true` and `leaveView` won't call any further user code. The original error will then propagate back up the stack and be reported correctly. A test is added to verify this behavior. PR Close #31244
2019-06-24 16:14:05 -04:00
leaveView(oldView, safeToRunHooks);
}
});
});
});