feat(material-experimental): add progress bar test harness skeleton (#16619)

* feat(material-experimental): add progress bar test harness skeleton

* use number coercion

Author: andrewseguin

.github/CODEOWNERS

@@ -94,6 +94,7 @@
 /src/material-experimental/mdc-chips/**            @mmalerba
 /src/material-experimental/mdc-helpers/**          @mmalerba
 /src/material-experimental/mdc-menu/**             @crisbeto
+/src/material-experimental/mdc-progress-bar/**     @andrewseguin
 # Note to implementer: please repossess
 /src/material-experimental/mdc-radio/**            @mmalerba
 /src/material-experimental/mdc-slide-toggle/**     @crisbeto

src/material-experimental/mdc-progress-bar/BUILD.bazel

@@ -0,0 +1,30 @@
+package(default_visibility = ["//visibility:public"])
+
+load("//tools:defaults.bzl", "ng_test_library", "ts_library")
+
+ts_library(
+    name = "harness",
+    srcs = glob(
+        ["harness/**/*.ts"],
+        exclude = ["**/*.spec.ts"],
+    ),
+    deps = [
+        "//src/cdk-experimental/testing",
+        "//src/cdk/coercion",
+    ],
+)
+
+ng_test_library(
+    name = "progress_bar_tests_lib",
+    srcs = glob(
+        ["**/*.spec.ts"],
+    ),
+    deps = [
+        ":harness",
+        "//src/cdk-experimental/testing",
+        "//src/cdk-experimental/testing/testbed",
+        "//src/cdk/coercion",
+        "//src/cdk/testing",
+        "//src/material/progress-bar",
+    ],
+)

src/material-experimental/mdc-progress-bar/harness/progress-bar-harness.spec.ts

@@ -0,0 +1,60 @@
+import {HarnessLoader} from '@angular/cdk-experimental/testing';
+import {TestbedHarnessEnvironment} from '@angular/cdk-experimental/testing/testbed';
+import {Component} from '@angular/core';
+import {ComponentFixture, TestBed} from '@angular/core/testing';
+import {MatProgressBarModule} from '@angular/material/progress-bar';
+
+import {MatProgressBarHarness} from './progress-bar-harness';
+
+let fixture: ComponentFixture<ProgressBarHarnessTest>;
+let loader: HarnessLoader;
+let progressBarHarness: typeof MatProgressBarHarness;
+
+describe('MatProgressBarHarness', () => {
+  beforeEach(async () => {
+    await TestBed
+        .configureTestingModule({
+          imports: [MatProgressBarModule],
+          declarations: [ProgressBarHarnessTest],
+        })
+        .compileComponents();
+
+    fixture = TestBed.createComponent(ProgressBarHarnessTest);
+    fixture.detectChanges();
+    loader = TestbedHarnessEnvironment.loader(fixture);
+    progressBarHarness = MatProgressBarHarness;
+  });
+
+  runTests();
+});
+
+function runTests() {
+  it('should load all progress bar harnesses', async () => {
+    const progressBars = await loader.getAllHarnesses(progressBarHarness);
+    expect(progressBars.length).toBe(2);
+  });
+
+  it('should get the value', async () => {
+    fixture.componentInstance.value = 50;
+    const [determinate, indeterminate] = await loader.getAllHarnesses(progressBarHarness);
+    expect(await determinate.getValue()).toBe(50);
+    expect(await indeterminate.getValue()).toBe(null);
+  });
+
+  it('should get the mode', async () => {
+    const [determinate, indeterminate] = await loader.getAllHarnesses(progressBarHarness);
+    expect(await determinate.getMode()).toBe('determinate');
+    expect(await indeterminate.getMode()).toBe('indeterminate');
+  });
+}
+
+// TODO: Add and test progress bars with modes `buffer` and `query`.
+@Component({
+  template: `
+    <mat-progress-bar mode="determinate" [value]="value"></mat-progress-bar>
+    <mat-progress-bar mode="indeterminate"></mat-progress-bar>
+  `
+})
+class ProgressBarHarnessTest {
+  value: number;
+}

src/material-experimental/mdc-progress-bar/harness/progress-bar-harness.ts

@@ -0,0 +1,30 @@
+/**
+ * @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} from '@angular/cdk-experimental/testing';
+import {coerceNumberProperty} from '@angular/cdk/coercion';
+
+/**
+ * Harness for interacting with a standard mat-progress-bar in tests.
+ * @dynamic
+ */
+export class MatProgressBarHarness extends ComponentHarness {
+  static hostSelector = 'mat-progress-bar';
+
+  /** Gets a promise for the progress bar's value. */
+  async getValue(): Promise<number|null> {
+    const host = await this.host();
+    const ariaValue = await host.getAttribute('aria-valuenow');
+    return ariaValue ? coerceNumberProperty(ariaValue) : null;
+  }
+
+  /** Gets a promise for the progress bar's mode. */
+  async getMode(): Promise<string|null> {
+    return (await this.host()).getAttribute('mode');
+  }
+}