test: add an experimental Webpack 5 E2E test

Author: clydin

tests/legacy-cli/e2e/tests/misc/webpack-5.ts

@@ -0,0 +1,33 @@
+import { rimraf } from '../../utils/fs';
+import { killAllProcesses, ng, silentYarn } from '../../utils/process';
+import { ngServe, updateJsonFile } from '../../utils/project';
+
+export default async function() {
+  // Setup project for yarn usage
+  await rimraf('node_modules');
+  await updateJsonFile('package.json', (json) => {
+    json.resolutions = { webpack: '5.0.0-beta.30' };
+  });
+  await silentYarn();
+  await silentYarn('webdriver-update');
+
+  // Ensure webpack 5 is used
+  const { stdout } = await silentYarn('list', '--pattern', 'webpack');
+  if (!/\swebpack@5/.test(stdout)) {
+    throw new Error('Expected Webpack 5 to be installed.');
+  }
+  if (/\swebpack@4/.test(stdout)) {
+    throw new Error('Expected Webpack 4 to not be installed.');
+  }
+
+  // Execute the CLI with Webpack 5
+  await ng('test', '--watch=false');
+  await ng('build');
+  await ng('build', '--prod');
+  await ng('e2e');
+  try {
+    await ngServe();
+  } finally {
+    killAllProcesses();
+  }
+}