feat(material-experimental): add test harness for radio-group

Follow-up for 583af19. This commit
introduces a new test harness for the `mat-radio-group` implementation.

Note that we can't provide harness methods for getting the selected
value because the selected value or the value of a radio-button are
part of the component-internal state (no way to determine from DOM)

Author: devversion

src/material-experimental/mdc-radio/harness/radio-harness-filters.ts

@@ -6,6 +6,11 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+export type RadioGroupHarnessFilters = {
+  id?: string;
+  name?: string;
+};
+
 export type RadioButtonHarnessFilters = {
   label?: string|RegExp,
   id?: string;

src/material-experimental/mdc-radio/harness/radio-harness.spec.ts

@@ -4,13 +4,14 @@ import {Component} from '@angular/core';
 import {ComponentFixture, TestBed} from '@angular/core/testing';
 import {ReactiveFormsModule} from '@angular/forms';
 import {MatRadioModule} from '@angular/material/radio';
-import {MatRadioButtonHarness} from './radio-harness';
+import {MatRadioButtonHarness, MatRadioGroupHarness} from './radio-harness';
 
 let fixture: ComponentFixture<MultipleRadioButtonsHarnessTest>;
 let loader: HarnessLoader;
 let radioButtonHarness: typeof MatRadioButtonHarness;
+let radioGroupHarness: typeof MatRadioGroupHarness;
 
-describe('MatRadioButtonHarness', () => {
+describe('standard radio harnesses', () => {
   describe('non-MDC-based', () => {
     beforeEach(async () => {
       await TestBed
@@ -24,9 +25,11 @@ describe('MatRadioButtonHarness', () => {
       fixture.detectChanges();
       loader = TestbedHarnessEnvironment.loader(fixture);
       radioButtonHarness = MatRadioButtonHarness;
+      radioGroupHarness = MatRadioGroupHarness;
     });
 
-    runTests();
+    describe('MatRadioButtonHarness', () => runRadioButtonTests());
+    describe('MatRadioGroupHarness', () => runRadioGroupTests());
   });
 
   describe(
@@ -36,11 +39,119 @@ describe('MatRadioButtonHarness', () => {
       });
 });
 
+/** Shared tests to run on both the original and MDC-based radio-group's. */
+function runRadioGroupTests() {
+  it('should load all radio-group harnesses', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness);
+    expect(groups.length).toBe(3);
+  });
+
+  it('should load radio-group with exact id', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness.with({id: 'my-group-2'}));
+    expect(groups.length).toBe(1);
+  });
+
+  it('should load radio-group by name', async () => {
+    let groups = await loader.getAllHarnesses(radioGroupHarness.with({name: 'my-group-2-name'}));
+    expect(groups.length).toBe(1);
+    expect(await groups[0].getId()).toBe('my-group-2');
+
+    groups = await loader.getAllHarnesses(radioGroupHarness.with({name: 'my-group-1-name'}));
+    expect(groups.length).toBe(1);
+    expect(await groups[0].getId()).toBe('my-group-1');
+  });
+
+  it('should throw when finding radio-group with specific name that has mismatched ' +
+         'radio-button names',
+     async () => {
+       fixture.componentInstance.thirdGroupButtonName = 'other-name';
+       fixture.detectChanges();
+
+       let errorMessage: string|null = null;
+       try {
+         await loader.getAllHarnesses(radioGroupHarness.with({name: 'third-group-name'}));
+       } catch (e) {
+         errorMessage = e.toString();
+       }
+
+       expect(errorMessage)
+           .toMatch(
+               /locator found a radio-group with name "third-group-name".*have mismatching names/);
+     });
+
+  it('should get name of radio-group', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness);
+    expect(groups.length).toBe(3);
+    expect(await groups[0].getName()).toBe('my-group-1-name');
+    expect(await groups[1].getName()).toBe('my-group-2-name');
+    expect(await groups[2].getName()).toBe('third-group-name');
+
+    fixture.componentInstance.secondGroupId = 'new-group';
+    fixture.detectChanges();
+
+    expect(await groups[1].getName()).toBe('new-group-name');
+
+    fixture.componentInstance.thirdGroupButtonName = 'other-button-name';
+    fixture.detectChanges();
+
+    let errorMessage: string|null = null;
+    try {
+      await groups[2].getName();
+    } catch (e) {
+      errorMessage = e.toString();
+    }
+
+    expect(errorMessage).toMatch(/Radio buttons in radio-group have mismatching names./);
+  });
+
+  it('should get id of radio-group', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness);
+    expect(groups.length).toBe(3);
+    expect(await groups[0].getId()).toBe('my-group-1');
+    expect(await groups[1].getId()).toBe('my-group-2');
+    expect(await groups[2].getId()).toBe('');
+
+    fixture.componentInstance.secondGroupId = 'new-group-name';
+    fixture.detectChanges();
+
+    expect(await groups[1].getId()).toBe('new-group-name');
+  });
+
+  it('should get selected value of radio-group', async () => {
+    const [firstGroup, secondGroup] = await loader.getAllHarnesses(radioGroupHarness);
+    expect(await firstGroup.getSelectedValue()).toBe('opt2');
+    expect(await secondGroup.getSelectedValue()).toBe(null);
+  });
+
+  it('should get radio-button harnesses of radio-group', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness);
+    expect(groups.length).toBe(3);
+
+    expect((await groups[0].getRadioButtons()).length).toBe(3);
+    expect((await groups[1].getRadioButtons()).length).toBe(1);
+    expect((await groups[2].getRadioButtons()).length).toBe(2);
+  });
+
+  it('should get selected radio-button harnesses of radio-group', async () => {
+    const groups = await loader.getAllHarnesses(radioGroupHarness);
+    expect(groups.length).toBe(3);
+
+    const groupOneSelected = await groups[0].getSelectedRadioButton();
+    const groupTwoSelected = await groups[1].getSelectedRadioButton();
+    const groupThreeSelected = await groups[2].getSelectedRadioButton();
+
+    expect(groupOneSelected).not.toBeNull();
+    expect(groupTwoSelected).toBeNull();
+    expect(groupThreeSelected).toBeNull();
+    expect(await groupOneSelected!.getId()).toBe('opt2-group-one');
+  });
+}
+
 /** Shared tests to run on both the original and MDC-based radio-button's. */
-function runTests() {
+function runRadioButtonTests() {
   it('should load all radio-button harnesses', async () => {
     const radios = await loader.getAllHarnesses(radioButtonHarness);
-    expect(radios.length).toBe(4);
+    expect(radios.length).toBe(9);
   });
 
   it('should load radio-button with exact label', async () => {
@@ -85,6 +196,13 @@ function runTests() {
     expect(await thirdRadio.getLabelText()).toBe('Option #3');
   });
 
+  it('should get value', async () => {
+    const [firstRadio, secondRadio, thirdRadio] = await loader.getAllHarnesses(radioButtonHarness);
+    expect(await firstRadio.getValue()).toBe('opt1');
+    expect(await secondRadio.getValue()).toBe('opt2');
+    expect(await thirdRadio.getValue()).toBe('opt3');
+  });
+
   it('should get disabled state', async () => {
     const [firstRadio] = await loader.getAllHarnesses(radioButtonHarness);
     expect(await firstRadio.isDisabled()).toBe(false);
@@ -141,6 +259,7 @@ function runTests() {
     expect(await radioButton.isRequired()).toBe(true);
   });
 }
+
 function getActiveElementTagName() {
   return document.activeElement ? document.activeElement.tagName.toLowerCase() : '';
 }
@@ -157,12 +276,32 @@ function getActiveElementTagName() {
       Option #{{i + 1}}
     </mat-radio-button>
 
-    <mat-radio-button id="required-radio" required name="acceptsTerms">
-      Accept terms of conditions
-    </mat-radio-button>
+    <mat-radio-group id="my-group-1" name="my-group-1-name">
+      <mat-radio-button *ngFor="let value of values"
+                        [checked]="value === 'opt2'"
+                        [value]="value"
+                        [id]="value + '-group-one'">
+        {{value}}
+      </mat-radio-button>
+    </mat-radio-group>
+
+
+    <mat-radio-group [id]="secondGroupId" [name]="secondGroupId + '-name'">
+      <mat-radio-button id="required-radio" required [value]="true">
+        Accept terms of conditions
+      </mat-radio-button>
+    </mat-radio-group>
+
+    <mat-radio-group [name]="thirdGroupName">
+      <mat-radio-button [value]="true">First</mat-radio-button>
+      <mat-radio-button [value]="false" [name]="thirdGroupButtonName"></mat-radio-button>
+    </mat-radio-group>
   `
 })
 class MultipleRadioButtonsHarnessTest {
   values = ['opt1', 'opt2', 'opt3'];
   disableAll = false;
+  secondGroupId = 'my-group-2';
+  thirdGroupName: string = 'third-group-name';
+  thirdGroupButtonName: string|undefined = undefined;
 }

src/material-experimental/mdc-radio/harness/radio-harness.ts

@@ -8,7 +8,133 @@
 
 import {ComponentHarness, HarnessPredicate} from '@angular/cdk-experimental/testing';
 import {coerceBooleanProperty} from '@angular/cdk/coercion';
-import {RadioButtonHarnessFilters} from './radio-harness-filters';
+import {RadioButtonHarnessFilters, RadioGroupHarnessFilters} from './radio-harness-filters';
+
+/**
+ * Harness for interacting with a standard mat-radio-group in tests.
+ * @dynamic
+ */
+export class MatRadioGroupHarness extends ComponentHarness {
+  static hostSelector = 'mat-radio-group';
+
+  /**
+   * Gets a `HarnessPredicate` that can be used to search for a radio-group with
+   * specific attributes.
+   * @param options Options for narrowing the search:
+   *   - `id` finds a radio-group with specific id.
+   *   - `name` finds a radio-group with specific name.
+   * @return a `HarnessPredicate` configured with the given options.
+   */
+  static with(options: RadioGroupHarnessFilters = {}): HarnessPredicate<MatRadioGroupHarness> {
+    return new HarnessPredicate(MatRadioGroupHarness)
+        .addOption('id', options.id, async (harness, id) => (await harness.getId()) === id)
+        .addOption('name', options.name, async (harness, name) => {
+          // Check if there is a radio-group which has the "name" attribute set
+          // to the expected group name. It's not possible to always determine
+          // the "name" of a radio-group by reading the attribute. This is because
+          // the radio-group does not set the "name" as an element attribute if the
+          // "name" value is set through a binding.
+          if (await harness._getGroupNameFromHost() === name) {
+            return true;
+          }
+          // Check if there is a group with radio-buttons that all have the same
+          // expected name. This implies that the group has the given name. It's
+          // not possible to always determine the name of a radio-group through
+          // the attribute because there is
+          const radioNames = await harness._getNamesFromRadioButtons();
+          if (radioNames.indexOf(name) === -1) {
+            return false;
+          }
+          if (!harness._checkRadioNamesInGroupEqual(radioNames)) {
+            throw Error(
+                `The locator found a radio-group with name "${name}", but some ` +
+                `radio-button's within the group have mismatching names, which is invalid.`);
+          }
+          return true;
+        });
+  }
+
+  private _radioButtons = this.locatorForAll(MatRadioButtonHarness);
+
+  /** Gets the name of the radio-group. */
+  async getName(): Promise<string|null> {
+    const hostName = await this._getGroupNameFromHost();
+    // It's not possible to always determine the "name" of a radio-group by reading
+    // the attribute. This is because the radio-group does not set the "name" as an
+    // element attribute if the "name" value is set through a binding.
+    if (hostName !== null) {
+      return hostName;
+    }
+    // In case we couldn't determine the "name" of a radio-group by reading the
+    // "name" attribute, we try to determine the "name" of the group by going
+    // through all radio buttons.
+    const radioNames = await this._getNamesFromRadioButtons();
+    if (!radioNames.length) {
+      return null;
+    }
+    if (!this._checkRadioNamesInGroupEqual(radioNames)) {
+      throw Error('Radio buttons in radio-group have mismatching names.');
+    }
+    return radioNames[0]!;
+  }
+
+  /** Gets the id of the radio-group. */
+  async getId(): Promise<string|null> {
+    return (await this.host()).getAttribute('id');
+  }
+
+  /** Gets the selected radio-button in a radio-group. */
+  async getSelectedRadioButton(): Promise<MatRadioButtonHarness|null> {
+    for (let radioButton of await this.getRadioButtons()) {
+      if (await radioButton.isChecked()) {
+        return radioButton;
+      }
+    }
+    return null;
+  }
+
+  /** Gets the selected value of the radio-group. */
+  async getSelectedValue(): Promise<string|null> {
+    const selectedRadio = await this.getSelectedRadioButton();
+    if (!selectedRadio) {
+      return null;
+    }
+    return selectedRadio.getValue();
+  }
+
+  /** Gets all radio buttons which are part of the radio-group. */
+  async getRadioButtons(): Promise<MatRadioButtonHarness[]> {
+    return (await this._radioButtons());
+  }
+
+  private async _getGroupNameFromHost() {
+    return (await this.host()).getAttribute('name');
+  }
+
+  private async _getNamesFromRadioButtons(): Promise<string[]> {
+    const groupNames: string[] = [];
+    for (let radio of await this.getRadioButtons()) {
+      const radioName = await radio.getName();
+      if (radioName !== null) {
+        groupNames.push(radioName);
+      }
+    }
+    return groupNames;
+  }
+
+  /** Checks if the specified radio names are all equal. */
+  private _checkRadioNamesInGroupEqual(radioNames: string[]): boolean {
+    let groupName: string|null = null;
+    for (let radioName of radioNames) {
+      if (groupName === null) {
+        groupName = radioName;
+      } else if (groupName !== radioName) {
+        return false;
+      }
+    }
+    return true;
+  }
+}
 
 /**
  * Harness for interacting with a standard mat-radio-button in tests.
@@ -23,6 +149,7 @@ export class MatRadioButtonHarness extends ComponentHarness {
    * @param options Options for narrowing the search:
    *   - `label` finds a radio-button with specific label text.
    *   - `name` finds a radio-button with specific name.
+   *   - `id` finds a radio-button with specific id.
    * @return a `HarnessPredicate` configured with the given options.
    */
   static with(options: RadioButtonHarnessFilters = {}): HarnessPredicate<MatRadioButtonHarness> {
@@ -67,6 +194,17 @@ export class MatRadioButtonHarness extends ComponentHarness {
     return (await this.host()).getAttribute('id');
   }
 
+  /**
+   * Gets the value of the radio-button. The radio-button value will be
+   * converted to a string.
+   *
+   * Note that this means that radio-button's with objects as value will
+   * intentionally have the `[object Object]` as return value.
+   */
+  async getValue(): Promise<string|null> {
+    return (await this._input()).getAttribute('value');
+  }
+
   /** Gets a promise for the radio-button's label text. */
   async getLabelText(): Promise<string> {
     return (await this._textLabel()).text();
@@ -99,3 +237,5 @@ export class MatRadioButtonHarness extends ComponentHarness {
     }
   }
 }
+
+export function checkElementsInArrayEqual(array: string[]) {}