refactor(material/schematics): move some general scss migration testing logic to separate file

Author: amysorto

src/material/schematics/ng-generate/mdc-migration/BUILD.bazel

@@ -16,6 +16,7 @@ ts_library(
     deps = [
         "//src/cdk/schematics",
         "@npm//@angular-devkit/schematics",
+        "@npm//@bazel/runfiles",
         "@npm//@types/node",
         "@npm//postcss",
         "@npm//postcss-scss",
@@ -56,7 +57,6 @@ ts_library(
         "//src/cdk/schematics/testing",
         "@npm//@angular-devkit/core",
         "@npm//@angular-devkit/schematics",
-        "@npm//@bazel/runfiles",
         "@npm//@types/jasmine",
         "@npm//@types/node",
     ],

src/material/schematics/ng-generate/mdc-migration/rules/components/button/button-styles.spec.ts

@@ -1,32 +1,22 @@
 import {createTestApp, patchDevkitTreeToExposeTypeScript} from '@angular/cdk/schematics/testing';
 import {SchematicTestRunner, UnitTestTree} from '@angular-devkit/schematics/testing';
-import {Schema} from '../../../schema';
-import {runfiles} from '@bazel/runfiles';
+import {createNewTestRunner, migrateComponent, THEME_FILE} from '../util';
 
 describe('button styles', () => {
   let runner: SchematicTestRunner;
   let cliAppTree: UnitTestTree;
-  const tsconfig = '/projects/material/tsconfig.app.json';
-  const themeFile = '/projects/material/src/theme.scss';
 
   async function runMigrationTest(oldFileContent: string, newFileContent: string) {
-    cliAppTree.create(themeFile, oldFileContent);
-    const tree = await migrate({tsconfig, components: ['button']});
-    expect(tree.readContent(themeFile)).toBe(newFileContent);
+    cliAppTree.create(THEME_FILE, oldFileContent);
+    const tree = await migrateComponent('button', runner, cliAppTree);
+    expect(tree.readContent(THEME_FILE)).toBe(newFileContent);
   }
 
   beforeEach(async () => {
-    runner = new SchematicTestRunner(
-      '@angular/material',
-      runfiles.resolveWorkspaceRelative('src/material/schematics/collection.json'),
-    );
+    runner = createNewTestRunner();
     cliAppTree = patchDevkitTreeToExposeTypeScript(await createTestApp(runner));
   });
 
-  async function migrate(options: Schema): Promise<UnitTestTree> {
-    return await runner.runSchematicAsync('mdcMigration', options, cliAppTree).toPromise();
-  }
-
   describe('mixin migrations', () => {
     it('should replace the old theme with the new ones', async () => {
       await runMigrationTest(

src/material/schematics/ng-generate/mdc-migration/rules/components/util.ts

@@ -0,0 +1,31 @@
+/**
+ * @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 {SchematicTestRunner, UnitTestTree} from '@angular-devkit/schematics/testing';
+import {runfiles} from '@bazel/runfiles';
+
+const TS_CONFIG = '/projects/material/tsconfig.app.json';
+
+export const THEME_FILE = '/projects/material/src/theme.scss';
+
+export function createNewTestRunner(): SchematicTestRunner {
+  return new SchematicTestRunner(
+    '@angular/material',
+    runfiles.resolveWorkspaceRelative('src/material/schematics/collection.json'),
+  );
+}
+
+export async function migrateComponent(
+  component: string,
+  runner: SchematicTestRunner,
+  tree: UnitTestTree,
+): Promise<UnitTestTree> {
+  return await runner
+    .runSchematicAsync('mdcMigration', {TS_CONFIG, components: [component]}, tree)
+    .toPromise();
+}