feat(material-experimental): add test harness for mdc-slider

devversion · devversion · commit cc69ceb69cfe · 2019-09-05T01:09:29.000+02:00
* Adds a test harness for the mdc-slider that complies with the
standard Angular Material slider test harness.
diff --git a/src/material-experimental/mdc-slider/harness/BUILD.bazel b/src/material-experimental/mdc-slider/harness/BUILD.bazel
@@ -21,6 +21,7 @@ ng_test_library(
         ":harness",
         "//src/cdk-experimental/testing",
         "//src/cdk-experimental/testing/testbed",
+        "//src/material-experimental/mdc-slider",
         "//src/material/slider",
     ],
 )
diff --git a/src/material-experimental/mdc-slider/harness/mdc-slider-harness.ts b/src/material-experimental/mdc-slider/harness/mdc-slider-harness.ts
@@ -0,0 +1,138 @@
+/**
+ * @license
+ * Copyright Google LLC 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 {ComponentHarness, HarnessPredicate} from '@angular/cdk-experimental/testing';
+import {coerceBooleanProperty, coerceNumberProperty} from '@angular/cdk/coercion';
+import {SliderHarnessFilters} from './slider-harness-filters';
+
+/**
+ * Harness for interacting with a MDC mat-slider in tests.
+ * @dynamic
+ */
+export class MatSliderHarness extends ComponentHarness {
+  static hostSelector = 'mat-slider';
+
+  /**
+   * Gets a `HarnessPredicate` that can be used to search for a mat-slider with
+   * specific attributes.
+   * @param options Options for narrowing the search:
+   *   - `selector` finds a slider whose host element matches the given selector.
+   *   - `id` finds a slider with specific id.
+   * @return a `HarnessPredicate` configured with the given options.
+   */
+  static with(options: SliderHarnessFilters = {}): HarnessPredicate<MatSliderHarness> {
+    return new HarnessPredicate(MatSliderHarness, options);
+  }
+
+  private _textLabel = this.locatorForOptional('.mdc-slider__pin-value-marker');
+  private _trackContainer = this.locatorFor('.mdc-slider__track-container');
+
+  /** Gets the slider's id. */
+  async getId(): Promise<string|null> {
+    const id = await (await this.host()).getProperty('id');
+    // In case no id has been specified, the "id" property always returns
+    // an empty string. To make this method more explicit, we return null.
+    return id !== '' ? id : null;
+  }
+
+  /**
+   * Gets the current display value of the slider. Returns null if the thumb
+   * label is disabled.
+   */
+  async getDisplayValue(): Promise<string|null> {
+    const textLabelEl = await this._textLabel();
+    return textLabelEl ? textLabelEl.text() : null;
+  }
+
+  /** Gets the current percentage value of the slider. */
+  async getPercentage(): Promise<number> {
+    return this._calculatePercentage(await this.getValue());
+  }
+
+  /** Gets the current value of the slider. */
+  async getValue(): Promise<number> {
+    return coerceNumberProperty(await (await this.host()).getAttribute('aria-valuenow'));
+  }
+
+  /** Gets the maximum value of the slider. */
+  async getMaxValue(): Promise<number> {
+    return coerceNumberProperty(await (await this.host()).getAttribute('aria-valuemax'));
+  }
+
+  /** Gets the minimum value of the slider. */
+  async getMinValue(): Promise<number> {
+    return coerceNumberProperty(await (await this.host()).getAttribute('aria-valuemin'));
+  }
+
+  /** Whether the slider is disabled. */
+  async isDisabled(): Promise<boolean> {
+    const disabled = (await this.host()).getAttribute('aria-disabled');
+    return coerceBooleanProperty(await disabled);
+  }
+
+  /** Gets the orientation of the slider. */
+  async getOrientation(): Promise<'horizontal'> {
+    // "aria-orientation" will always be set to "horizontal" for the MDC
+    // slider as there is no vertical slider support yet.
+    return (await this.host()).getAttribute('aria-orientation') as any;
+  }
+
+  /**
+   * Sets the value of the slider by clicking on the slider track.
+   *
+   * Note that in rare cases the value cannot be set to the exact specified value. This
+   * can happen if not every value of the slider maps to a single pixel that could be
+   * clicked using mouse interaction. In such cases consider using the keyboard to
+   * select the given value or expand the slider's size for a better user experience.
+   */
+  async setValue(value: number): Promise<void> {
+    await this._stabilizeLayout();
+    const [sliderEl, trackContainer] =
+        await Promise.all([this.host(), this._trackContainer()]);
+    let percentage = await this._calculatePercentage(value);
+    const {width} = await trackContainer.getDimensions();
+
+    // In case the slider is displayed in RTL mode, we need to invert the
+    // percentage so that the proper value is set.
+    if (await sliderEl.hasClass('mat-slider-invert-mouse-coords')) {
+      percentage = 1 - percentage;
+    }
+
+    // We need to round the new coordinates because creating fake DOM
+    // events will cause the coordinates to be rounded down.
+    await sliderEl.click(Math.round(width * percentage), 0);
+  }
+
+  /**
+   * Focuses the slider and returns a void promise that indicates when the
+   * action is complete.
+   */
+  async focus(): Promise<void> {
+    return (await this.host()).focus();
+  }
+
+  /**
+   * Blurs the slider and returns a void promise that indicates when the
+   * action is complete.
+   */
+  async blur(): Promise<void> {
+    return (await this.host()).blur();
+  }
+
+  /** Calculates the percentage of the given value. */
+  private async _calculatePercentage(value: number) {
+    const [min, max] = await Promise.all([this.getMinValue(), this.getMaxValue()]);
+    return (value - min) / (max - min);
+  }
+
+  private async _stabilizeLayout() {
+    return new Promise(resolve => {
+      requestAnimationFrame(() => resolve());
+    });
+  }
+}
diff --git a/src/material-experimental/mdc-slider/harness/slider-harness.spec.ts b/src/material-experimental/mdc-slider/harness/slider-harness.spec.ts
@@ -1,8 +1,10 @@
 import {HarnessLoader} from '@angular/cdk-experimental/testing';
 import {TestbedHarnessEnvironment} from '@angular/cdk-experimental/testing/testbed';
-import {Component} from '@angular/core';
+import {Component, CUSTOM_ELEMENTS_SCHEMA} from '@angular/core';
 import {ComponentFixture, TestBed} from '@angular/core/testing';
 import {MatSliderModule} from '@angular/material/slider';
+import {MatSliderModule as MatMdcSliderModule} from '../module';
+import {MatSliderHarness as MatMdcSliderHarness} from './mdc-slider-harness';
 import {MatSliderHarness} from './slider-harness';
 
 let fixture: ComponentFixture<SliderHarnessTest>;
@@ -25,18 +27,37 @@ describe('MatSliderHarness', () => {
       sliderHarness = MatSliderHarness;
     });
 
-    runTests();
+    // Standard slider supports vertical and inverted sliders.
+    createTests(true, true);
   });
 
   describe(
       'MDC-based',
       () => {
-          // TODO: run tests for MDC based slider once implemented.
+        beforeEach(async () => {
+          await TestBed
+            .configureTestingModule({
+              imports: [MatMdcSliderModule],
+              declarations: [SliderHarnessTest],
+              schemas: [CUSTOM_ELEMENTS_SCHEMA]
+            })
+            .compileComponents();
+
+          fixture = TestBed.createComponent(SliderHarnessTest);
+          fixture.detectChanges();
+          loader = TestbedHarnessEnvironment.loader(fixture);
+          // Public APIs are the same as "MatSliderHarness", but cast is necessary because
+          // of different private fields.
+          sliderHarness = MatMdcSliderHarness as any;
+        });
+
+        // MDC slider does not support vertical or inverted sliders.
+        createTests(false, false);
       });
 });
 
 /** Shared tests to run on both the original and MDC-based sliders. */
-function runTests() {
+function createTests(supportsVertical: boolean, supportsInvert: boolean) {
   it('should load all slider harnesses', async () => {
     const sliders = await loader.getAllHarnesses(sliderHarness);
     expect(sliders.length).toBe(3);
@@ -84,7 +105,7 @@ function runTests() {
 
   it('should get display value of slider', async () => {
     const sliders = await loader.getAllHarnesses(sliderHarness);
-    expect(await sliders[0].getDisplayValue()).toBe('50');
+    expect(await sliders[0].getDisplayValue()).toBe(null);
     expect(await sliders[1].getDisplayValue()).toBe('Null');
     expect(await sliders[2].getDisplayValue()).toBe('#225');
   });
@@ -93,18 +114,20 @@ function runTests() {
     const sliders = await loader.getAllHarnesses(sliderHarness);
     expect(await sliders[0].getOrientation()).toBe('horizontal');
     expect(await sliders[1].getOrientation()).toBe('horizontal');
-    expect(await sliders[2].getOrientation()).toBe('vertical');
+    expect(await sliders[2].getOrientation()).toBe(supportsVertical ? 'vertical' : 'horizontal');
   });
 
   it('should be able to focus slider', async () => {
-    const [slider] = await loader.getAllHarnesses(sliderHarness);
+    // the first slider is disabled.
+    const slider = (await loader.getAllHarnesses(sliderHarness))[1];
     expect(getActiveElementTagName()).not.toBe('mat-slider');
     await slider.focus();
     expect(getActiveElementTagName()).toBe('mat-slider');
   });
 
   it('should be able to blur slider', async () => {
-    const [slider] = await loader.getAllHarnesses(sliderHarness);
+    // the first slider is disabled.
+    const slider = (await loader.getAllHarnesses(sliderHarness))[1];
     expect(getActiveElementTagName()).not.toBe('mat-slider');
     await slider.focus();
     expect(getActiveElementTagName()).toBe('mat-slider');
@@ -139,43 +162,45 @@ function runTests() {
     expect(await sliders[1].getValue()).toBe(80);
   });
 
-  it('should be able to set value of inverted slider', async () => {
+  it('should get disabled state of slider', async () => {
     const sliders = await loader.getAllHarnesses(sliderHarness);
-    expect(await sliders[1].getValue()).toBe(0);
-    expect(await sliders[2].getValue()).toBe(225);
+    expect(await sliders[0].isDisabled()).toBe(true);
+    expect(await sliders[1].isDisabled()).toBe(false);
+    expect(await sliders[2].isDisabled()).toBe(false);
+  });
 
-    fixture.componentInstance.invertSliders = true;
-    fixture.detectChanges();
+  if (supportsInvert) {
+    it('should be able to set value of inverted slider', async () => {
+      const sliders = await loader.getAllHarnesses(sliderHarness);
+      expect(await sliders[1].getValue()).toBe(0);
+      expect(await sliders[2].getValue()).toBe(225);
 
-    await sliders[1].setValue(75);
-    await sliders[2].setValue(210);
+      fixture.componentInstance.invertSliders = true;
+      fixture.detectChanges();
 
-    expect(await sliders[1].getValue()).toBe(75);
-    expect(await sliders[2].getValue()).toBe(210);
-  });
+      await sliders[1].setValue(75);
+      await sliders[2].setValue(210);
 
-  it('should be able to set value of inverted slider in rtl', async () => {
-    const sliders = await loader.getAllHarnesses(sliderHarness);
-    expect(await sliders[1].getValue()).toBe(0);
-    expect(await sliders[2].getValue()).toBe(225);
+      expect(await sliders[1].getValue()).toBe(75);
+      expect(await sliders[2].getValue()).toBe(210);
+    });
 
-    fixture.componentInstance.invertSliders = true;
-    fixture.componentInstance.dir = 'rtl';
-    fixture.detectChanges();
+    it('should be able to set value of inverted slider in rtl', async () => {
+      const sliders = await loader.getAllHarnesses(sliderHarness);
+      expect(await sliders[1].getValue()).toBe(0);
+      expect(await sliders[2].getValue()).toBe(225);
 
-    await sliders[1].setValue(75);
-    await sliders[2].setValue(210);
+      fixture.componentInstance.invertSliders = true;
+      fixture.componentInstance.dir = 'rtl';
+      fixture.detectChanges();
 
-    expect(await sliders[1].getValue()).toBe(75);
-    expect(await sliders[2].getValue()).toBe(210);
-  });
+      await sliders[1].setValue(75);
+      await sliders[2].setValue(210);
 
-  it('should get disabled state of slider', async () => {
-    const sliders = await loader.getAllHarnesses(sliderHarness);
-    expect(await sliders[0].isDisabled()).toBe(true);
-    expect(await sliders[1].isDisabled()).toBe(false);
-    expect(await sliders[2].isDisabled()).toBe(false);
-  });
+      expect(await sliders[1].getValue()).toBe(75);
+      expect(await sliders[2].getValue()).toBe(210);
+    });
+  }
 }
 
 function getActiveElementTagName() {
@@ -187,12 +212,12 @@ function getActiveElementTagName() {
     <mat-slider value="50" disabled></mat-slider>
     <div [dir]="dir">
       <mat-slider [id]="sliderId" [displayWith]="displayFn"
-                  [invert]="invertSliders"></mat-slider>
+                  [invert]="invertSliders" thumbLabel></mat-slider>
     </div>
     <mat-slider min="200" max="250" value="225" [displayWith]="displayFn" vertical
-                [invert]="invertSliders">
+                [invert]="invertSliders" thumbLabel>
     </mat-slider>
-    `
+    `,
 })
 class SliderHarnessTest {
   sliderId = 'my-slider';
diff --git a/src/material-experimental/mdc-slider/harness/slider-harness.ts b/src/material-experimental/mdc-slider/harness/slider-harness.ts
@@ -40,9 +40,16 @@ export class MatSliderHarness extends ComponentHarness {
     return id !== '' ? id : null;
   }
 
-  /** Gets the current display value of the slider. */
-  async getDisplayValue(): Promise<string> {
-    return (await this._textLabel()).text();
+  /**
+   * Gets the current display value of the slider. Returns null if the thumb
+   * label is disabled.
+   */
+  async getDisplayValue(): Promise<string|null> {
+    const [host, textLabel] = await Promise.all([this.host(), this._textLabel()]);
+    if (await host.hasClass('mat-slider-thumb-label-showing')) {
+      return textLabel.text();
+    }
+    return null;
   }
 
   /** Gets the current percentage value of the slider. */
diff --git a/src/material-experimental/mdc-slider/slider.ts b/src/material-experimental/mdc-slider/slider.ts
@@ -90,6 +90,9 @@ export class MatSliderChange {
     '[class.mdc-slider--discrete]': 'thumbLabel',
     '[class.mat-slider-has-ticks]': 'tickInterval !== 0',
     '[class.mat-slider-thumb-label-showing]': 'thumbLabel',
+    // Class binding which is only used by the test harness as there is no other
+    // way for the harness to detect if mouse coordinates need to be inverted.
+    '[class.mat-slider-invert-mouse-coords]': '_isRtl()',
     '[class.mat-slider-disabled]': 'disabled',
     '[class.mat-primary]': 'color == "primary"',
     '[class.mat-accent]': 'color == "accent"',
@@ -298,7 +301,7 @@ export class MatSlider implements AfterViewInit, OnChanges, OnDestroy, ControlVa
           this._trackMarker.nativeElement.style.setProperty(
               'background', this._getTrackMarkersBackground(min, max, step));
         },
-    isRTL: () => this._dir && this._dir.value === 'rtl',
+    isRTL: () => this._isRtl(),
   };
 
   /** Instance of the MDC slider foundation for this slider. */
@@ -352,10 +355,12 @@ export class MatSlider implements AfterViewInit, OnChanges, OnDestroy, ControlVa
     (this._foundation as any).isDiscrete_ = true;
 
     this._syncStep();
-    this._syncValue();
     this._syncMax();
     this._syncMin();
     this._syncDisabled();
+    // Note that "value" needs to be synced after "max" and "min" because otherwise
+    // the value will be clamped by the MDC foundation implementation.
+    this._syncValue();
   }
 
   ngOnChanges(changes: SimpleChanges) {
@@ -476,6 +481,11 @@ export class MatSlider implements AfterViewInit, OnChanges, OnDestroy, ControlVa
     this._foundation.setDisabled(this.disabled);
   }
 
+  /** Whether the slider is displayed in RTL-mode. */
+  _isRtl(): boolean {
+    return this._dir && this._dir.value === 'rtl';
+  }
+
   /**
    * Registers a callback to be triggered when the value has changed.
    * Implemented as part of ControlValueAccessor.

Original file line number	Diff line number	Diff line change
`@@ -21,6 +21,7 @@ ng_test_library(`
`21`	`21`	`":harness",`
`22`	`22`	`"//src/cdk-experimental/testing",`
`23`	`23`	`"//src/cdk-experimental/testing/testbed",`
	`24`	`+ "//src/material-experimental/mdc-slider",`
`24`	`25`	`"//src/material/slider",`
`25`	`26`	`],`
`26`	`27`	`)`