fix(ng-core): WrappedControlSuperclass gracefully handles errors th…

…rown from `innerToOuter()` and `outerToInner()`
simontonsoftware · Nov 6, 2021 · 45599aa · 45599aa
1 parent 6e07405
commit 45599aa
Show file tree

Hide file tree

Showing 4 changed files with 135 additions and 15 deletions.
diff --git a/projects/ng-core/src/lib/wrapped-control-superclass.spec.ts b/projects/ng-core/src/lib/wrapped-control-superclass.spec.ts
@@ -1,4 +1,9 @@
-import { ChangeDetectionStrategy, Component, Input } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  ErrorHandler,
+  Input,
+} from '@angular/core';
 import {
   ComponentFixtureAutoDetect,
   flushMicrotasks,
@@ -10,7 +15,7 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms';
 import { By } from '@angular/platform-browser';
-import { ComponentContext } from '@s-libs/ng-dev';
+import { ComponentContext, expectSingleCallAndReset } from '@s-libs/ng-dev';
 import { Observable } from 'rxjs';
 import { filter, map } from 'rxjs/operators';
 import { click, find, findButton, setValue } from '../test-helpers';
@@ -156,6 +161,95 @@ describe('WrappedControlSuperclass', () => {
       expect(inputs[1].disabled).toBe(true);
     });
   });
+
+  it('gracefully handles an error in .innerToOuter()', () => {
+    @Component({
+      selector: `sl-error-in`,
+      template: `<input [formControl]="control" />`,
+      providers: [provideValueAccessor(ErrorInComponent)],
+    })
+    class ErrorInComponent extends WrappedControlSuperclass<number> {
+      control = new FormControl();
+      override outerToInner = jasmine.createSpy();
+    }
+
+    @Component({
+      template: `<sl-error-in [(ngModel)]="value"></sl-error-in>`,
+    })
+    class WrapperComponent {
+      @Input() value!: string;
+    }
+
+    const handleError = jasmine.createSpy();
+    const ctx = new ComponentContext(WrapperComponent, {
+      declarations: [ErrorInComponent],
+      imports: [FormsModule, ReactiveFormsModule],
+      providers: [{ provide: ErrorHandler, useValue: { handleError } }],
+    });
+    ctx.run(async () => {
+      const control: ErrorInComponent = ctx.fixture.debugElement.query(
+        By.directive(ErrorInComponent),
+      ).componentInstance;
+      const input: HTMLInputElement = ctx.fixture.debugElement.query(
+        By.css('input'),
+      ).nativeElement;
+
+      const error = new Error();
+      control.outerToInner.and.throwError(error);
+      ctx.assignInputs({ value: 'wont show' });
+      expectSingleCallAndReset(handleError, error);
+      expect(input.value).toBe('');
+
+      control.outerToInner.and.returnValue('restored');
+      ctx.assignInputs({ value: 'will show' });
+      expect(input.value).toBe('restored');
+    });
+  });
+
+  it('gracefully handles an error in .outerToInner()', () => {
+    @Component({
+      selector: `sl-error-out`,
+      template: `<input [formControl]="control" />`,
+      providers: [provideValueAccessor(ErrorOutComponent)],
+    })
+    class ErrorOutComponent extends WrappedControlSuperclass<number> {
+      control = new FormControl();
+      override innerToOuter = jasmine.createSpy();
+    }
+
+    @Component({
+      template: `<sl-error-out [(ngModel)]="value"></sl-error-out>`,
+    })
+    class WrapperComponent {
+      value = 'initial value';
+    }
+
+    const handleError = jasmine.createSpy();
+    const ctx = new ComponentContext(WrapperComponent, {
+      declarations: [ErrorOutComponent],
+      imports: [FormsModule, ReactiveFormsModule],
+      providers: [{ provide: ErrorHandler, useValue: { handleError } }],
+    });
+    ctx.run(async () => {
+      const wrapper = ctx.getComponentInstance();
+      const control: ErrorOutComponent = ctx.fixture.debugElement.query(
+        By.directive(ErrorOutComponent),
+      ).componentInstance;
+      const input: HTMLInputElement = ctx.fixture.debugElement.query(
+        By.css('input'),
+      ).nativeElement;
+
+      const error = new Error();
+      control.innerToOuter.and.throwError(error);
+      setValue(input, 'wont show');
+      expectSingleCallAndReset(handleError, error);
+      expect(wrapper.value).toBe('initial value');
+
+      control.innerToOuter.and.returnValue('restored');
+      setValue(input, 'will show');
+      expect(wrapper.value).toBe('restored');
+    });
+  });
 });
 
 describe('WrappedControlSuperclass tests using an old style fixture', () => {

diff --git a/projects/ng-core/src/lib/wrapped-control-superclass.ts b/projects/ng-core/src/lib/wrapped-control-superclass.ts
@@ -1,7 +1,14 @@
-import { Directive, Injector, OnInit } from '@angular/core';
+import { Directive, ErrorHandler, Injector, OnInit } from '@angular/core';
 import { AbstractControl } from '@angular/forms';
 import { wrapMethod } from '@s-libs/js-core';
-import { Observable, Subject } from 'rxjs';
+import { bindKey, flow } from '@s-libs/micro-dash';
+import {
+  MonoTypeOperatorFunction,
+  Observable,
+  retry,
+  Subject,
+  tap,
+} from 'rxjs';
 import { map } from 'rxjs/operators';
 import { FormComponentSuperclass } from './form-component-superclass';
 
@@ -75,13 +82,18 @@ export abstract class WrappedControlSuperclass<OuterType, InnerType = OuterType>
   /** Bind this to your inner form control to make all the magic happen. */
   abstract control: AbstractControl;
 
-  private incomingValues$ = new Subject<OuterType>();
+  #incomingValues$ = new Subject<OuterType>();
+  #errorHandler: ErrorHandler;
 
   constructor(injector: Injector) {
     super(injector);
-    this.subscribeTo(this.setUpOuterToInner$(this.incomingValues$), (inner) => {
-      this.control.setValue(inner, { emitEvent: false });
-    });
+    this.#errorHandler = injector.get(ErrorHandler);
+    this.subscribeTo(
+      this.setUpOuterToInner$(this.#incomingValues$),
+      (inner) => {
+        this.control.setValue(inner, { emitEvent: false });
+      },
+    );
   }
 
   ngOnInit(): void {
@@ -100,7 +112,7 @@ export abstract class WrappedControlSuperclass<OuterType, InnerType = OuterType>
 
   /** Called as angular propagates values changes to this `ControlValueAccessor`. You normally do not need to use it. */
   handleIncomingValue(outer: OuterType): void {
-    this.incomingValues$.next(outer);
+    this.#incomingValues$.next(outer);
   }
 
   /** Called as angular propagates disabled changes to this `ControlValueAccessor`. You normally do not need to use it. */
@@ -140,7 +152,10 @@ export abstract class WrappedControlSuperclass<OuterType, InnerType = OuterType>
   protected setUpOuterToInner$(
     outer$: Observable<OuterType>,
   ): Observable<InnerType> {
-    return outer$.pipe(map((outer) => this.outerToInner(outer)));
+    return outer$.pipe(
+      map((outer) => this.outerToInner(outer)),
+      this.#handleError(),
+    );
   }
 
   /**
@@ -170,6 +185,16 @@ export abstract class WrappedControlSuperclass<OuterType, InnerType = OuterType>
   protected setUpInnerToOuter$(
     inner$: Observable<InnerType>,
   ): Observable<OuterType> {
-    return inner$.pipe(map((inner) => this.innerToOuter(inner)));
+    return inner$.pipe(
+      map((inner) => this.innerToOuter(inner)),
+      this.#handleError(),
+    );
+  }
+
+  #handleError<T>(): MonoTypeOperatorFunction<T> {
+    return flow(
+      tap<T>({ error: bindKey(this.#errorHandler, 'handleError') }),
+      retry(),
+    );
   }
 }
diff --git a/projects/ng-core/src/lib/wrapped-form-control-superclass.spec.ts b/projects/ng-core/src/lib/wrapped-form-control-superclass.spec.ts
@@ -6,7 +6,7 @@ import { WrappedFormControlSuperclass } from './wrapped-form-control-superclass'
 
 describe('WrappedFormControlSuperclass', () => {
   it('provides a FormControl', () => {
-    @Component({ template: `<input [formControl]="control" />` })
+    @Component({ template: `` })
     class SimpleControl extends WrappedFormControlSuperclass<string> {}
 
     const ctx = new ComponentContext(SimpleControl, {

diff --git a/projects/ng-core/src/test-helpers.ts b/projects/ng-core/src/test-helpers.ts
@@ -1,4 +1,5 @@
-import { ComponentFixture, flushMicrotasks } from '@angular/core/testing';
+import { ComponentFixture } from '@angular/core/testing';
+import { AngularContext } from '@s-libs/ng-dev';
 
 export function findButton(
   fixture: ComponentFixture<any>,
@@ -30,12 +31,12 @@ export function find<T extends Element>(
 
 export function click(element: Element): void {
   element.dispatchEvent(new MouseEvent('click', { bubbles: true }));
-  flushMicrotasks();
+  AngularContext.getCurrent()!.tick();
 }
 
 export function setValue(input: HTMLInputElement, value: string): void {
   input.value = value;
   input.dispatchEvent(new Event('input', { bubbles: true }));
   input.dispatchEvent(new Event('change', { bubbles: true }));
-  flushMicrotasks();
+  AngularContext.getCurrent()!.tick();
 }