refactor(@angular-devkit/schematics-cli): use custom indent logger and improve tests

Replaces `createConsoleLogger` with a custom `logging.IndentLogger`
implementation that respects custom output streams.

Also refactors tests to use standard `PassThrough` streams and
`stripVTControlCharacters` instead of custom mocks.

Author: clydin

packages/angular_devkit/schematics_cli/bin/schematics.ts

@@ -8,7 +8,6 @@
  */
 
 import { JsonValue, logging, schema } from '@angular-devkit/core';
-import { ProcessOutput, createConsoleLogger } from '@angular-devkit/core/node';
 import { UnsuccessfulWorkflowExecution, strings } from '@angular-devkit/schematics';
 import { NodeWorkflow } from '@angular-devkit/schematics/tools';
 import { existsSync } from 'node:fs';
@@ -50,8 +49,8 @@ function removeLeadingSlash(value: string): string {
 
 export interface MainOptions {
   args: string[];
-  stdout?: ProcessOutput;
-  stderr?: ProcessOutput;
+  stdout?: NodeJS.WritableStream;
+  stderr?: NodeJS.WritableStream;
 }
 
 function _listSchematics(workflow: NodeWorkflow, collectionName: string, logger: logging.Logger) {
@@ -217,21 +216,45 @@ function getPackageManagerName() {
   return 'npm';
 }
 
+function createLogger(
+  verbose: boolean,
+  stdout: NodeJS.WritableStream,
+  stderr: NodeJS.WritableStream,
+): logging.Logger {
+  const logger = new logging.IndentLogger('schematics');
+  const colorLevels: Record<string, (message: string, stream: NodeJS.WritableStream) => string> = {
+    info: (s) => s,
+    debug: (s) => s,
+    warn: (s, stream) => styleText(['bold', 'yellow'], s, { stream }),
+    error: (s, stream) => styleText(['bold', 'red'], s, { stream }),
+    fatal: (s, stream) => styleText(['bold', 'red'], s, { stream }),
+  };
+
+  logger.subscribe((entry) => {
+    if (entry.level === 'debug' && !verbose) {
+      return;
+    }
+
+    const output =
+      entry.level === 'warn' || entry.level === 'fatal' || entry.level === 'error'
+        ? stderr
+        : stdout;
+    const color = colorLevels[entry.level];
+    const message = color ? color(entry.message, output) : entry.message;
+    output.write(message + '\n');
+  });
+
+  return logger;
+}
+
 export async function main({
   args,
   stdout = process.stdout,
   stderr = process.stderr,
 }: MainOptions): Promise<0 | 1> {
   const { cliOptions, schematicOptions, _ } = parseOptions(args);
 
-  /** Create the DevKit Logger used through the CLI. */
-  const logger = createConsoleLogger(!!cliOptions.verbose, stdout, stderr, {
-    info: (s) => s,
-    debug: (s) => s,
-    warn: (s) => styleText(['bold', 'yellow'], s),
-    error: (s) => styleText(['bold', 'red'], s),
-    fatal: (s) => styleText(['bold', 'red'], s),
-  });
+  const logger = createLogger(!!cliOptions.verbose, stdout, stderr);
 
   if (cliOptions.help) {
     logger.info(getUsage());

packages/angular_devkit/schematics_cli/test/schematics_spec.ts

@@ -6,32 +6,24 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
+import { PassThrough } from 'node:stream';
+import { stripVTControlCharacters } from 'node:util';
 import { main } from '../bin/schematics';
 
-// We only care about the write method in these mocks of NodeJS.WriteStream.
-class MockWriteStream {
-  lines: string[] = [];
-  write(str: string) {
-    // Strip color control characters.
-    this.lines.push(str.replace(/[^\x20-\x7F]\[\d+m/g, ''));
-
-    return true;
-  }
-}
-
 describe('schematics-cli binary', () => {
-  let stdout: MockWriteStream, stderr: MockWriteStream;
+  let stdout: PassThrough, stderr: PassThrough;
 
   beforeEach(() => {
-    stdout = new MockWriteStream();
-    stderr = new MockWriteStream();
+    stdout = new PassThrough();
+    stderr = new PassThrough();
   });
 
   it('list-schematics works', async () => {
     const args = ['--list-schematics'];
     const res = await main({ args, stdout, stderr });
-    expect(stdout.lines).toMatch(/blank/);
-    expect(stdout.lines).toMatch(/schematic/);
+    const output = stripVTControlCharacters(stdout.read()?.toString() || '');
+    expect(output).toMatch(/blank/);
+    expect(output).toMatch(/schematic/);
     expect(res).toEqual(0);
   });
 
@@ -45,30 +37,33 @@ describe('schematics-cli binary', () => {
   it('dry-run works', async () => {
     const args = ['blank', 'foo', '--dry-run'];
     const res = await main({ args, stdout, stderr });
-    expect(stdout.lines).toMatch(/CREATE foo\/README.md/);
-    expect(stdout.lines).toMatch(/CREATE foo\/.gitignore/);
-    expect(stdout.lines).toMatch(/CREATE foo\/src\/foo\/index.ts/);
-    expect(stdout.lines).toMatch(/CREATE foo\/src\/foo\/index_spec.ts/);
-    expect(stdout.lines).toMatch(/Dry run enabled./);
+    const output = stripVTControlCharacters(stdout.read()?.toString() || '');
+    expect(output).toMatch(/CREATE foo\/README.md/);
+    expect(output).toMatch(/CREATE foo\/.gitignore/);
+    expect(output).toMatch(/CREATE foo\/src\/foo\/index.ts/);
+    expect(output).toMatch(/CREATE foo\/src\/foo\/index_spec.ts/);
+    expect(output).toMatch(/Dry run enabled./);
     expect(res).toEqual(0);
   });
 
   it('dry-run is default when debug mode', async () => {
     const args = ['blank', 'foo', '--debug'];
     const res = await main({ args, stdout, stderr });
-    expect(stdout.lines).toMatch(/Debug mode enabled./);
-    expect(stdout.lines).toMatch(/CREATE foo\/README.md/);
-    expect(stdout.lines).toMatch(/CREATE foo\/.gitignore/);
-    expect(stdout.lines).toMatch(/CREATE foo\/src\/foo\/index.ts/);
-    expect(stdout.lines).toMatch(/CREATE foo\/src\/foo\/index_spec.ts/);
-    expect(stdout.lines).toMatch(/Dry run enabled by default in debug mode./);
+    const output = stripVTControlCharacters(stdout.read()?.toString() || '');
+    expect(output).toMatch(/Debug mode enabled./);
+    expect(output).toMatch(/CREATE foo\/README.md/);
+    expect(output).toMatch(/CREATE foo\/.gitignore/);
+    expect(output).toMatch(/CREATE foo\/src\/foo\/index.ts/);
+    expect(output).toMatch(/CREATE foo\/src\/foo\/index_spec.ts/);
+    expect(output).toMatch(/Dry run enabled by default in debug mode./);
     expect(res).toEqual(0);
   });
 
   it('error when no name is provided', async () => {
     const args = ['blank'];
     const res = await main({ args, stdout, stderr });
-    expect(stderr.lines).toMatch(/Error: name option is required/);
+    const output = stripVTControlCharacters(stderr.read()?.toString() || '');
+    expect(output).toMatch(/Error: name option is required/);
     expect(res).toEqual(1);
   });
 });