fix(ng-dev): improve spinner experience when executed in a CI environment

ng-dev/perf/workflow/workflow.ts

@@ -1,10 +1,9 @@
 import {ChildProcess} from '../../utils/child-process.js';
-import {green} from '../../utils/logging.js';
 import {Spinner} from '../../utils/spinner.js';
 import {Workflow} from './loader.js';
 
 export async function measureWorkflow({name, workflow, prepare, cleanup}: Workflow) {
-  const spinner = new Spinner('');
+  const spinner = new Spinner();
   try {
     if (prepare) {
       spinner.update('Preparing environment for workflow execution');
@@ -32,7 +31,7 @@ export async function measureWorkflow({name, workflow, prepare, cleanup}: Workfl
 
     const results = performance.measure(name, 'start', 'end');
 
-    spinner.complete(` ${green('✓')} ${name}: ${results.duration.toFixed(2)}ms`);
+    spinner.success(`${name}: ${results.duration.toFixed(2)}ms`);
 
     return results.toJSON();
   } finally {

ng-dev/utils/spinner.ts

@@ -7,27 +7,74 @@
  */
 
 import {cursorTo, clearLine} from 'readline';
+import {green, red} from './logging.js';
 
+/** Whether execution is in a CI environment. */
+const IS_CI = process.env['CI'];
 /** ANSI escape code to hide cursor in terminal. */
 const hideCursor = '\x1b[?25l';
 /** ANSI escape code to show cursor in terminal. */
 const showCursor = '\x1b[?25h';
 
 export class Spinner {
-  /** Whether the spinner is currently running. */
-  private isRunning = true;
+  /** Whether the spinner is marked as completed. */
+  private completed = false;
   /** The id of the interval being used to trigger frame printing. */
-  private intervalId = setInterval(() => this.printFrame(), 125);
+  private intervalId = setInterval(() => this.printFrame(), IS_CI ? 2500 : 125);
   /** The characters to iterate through to create the appearance of spinning in the spinner. */
   private spinnerCharacters = ['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'];
   /** The index of the spinner character used in the frame. */
   private currentSpinnerCharacterIndex = 0;
   /** The current text of the spinner. */
-  private text: string = '';
+  private _text: string = '';
+  private set text(text: string | undefined) {
+    this._text = text || this._text;
+    this.printFrame(this.getNextSpinnerCharacter(), text);
+  }
+  private get text(): string {
+    return this._text;
+  }
+
+  constructor();
+  constructor(text: string);
+  constructor(text?: string) {
+    this.hideCursor();
+    this.text = text;
+  }
+
+  /** Updates the spinner text with the provided text. */
+  update(text: string) {
+    this.text = text;
+  }
 
-  constructor(text: string) {
-    process.stdout.write(hideCursor);
-    this.update(text);
+  /** Completes the spinner marking it as successful with a `✓`. */
+  success(text: string): void {
+    this._complete(green('✓'), text);
+  }
+
+  /** Completes the spinner marking it as failing with an `✘`. */
+  failure(text: string): void {
+    this._complete(red('✘'), text);
+  }
+
+  /** Completes the spinner. */
+  complete() {
+    this._complete('', this.text);
+  }
+
+  /**
+   * Internal implementation for completing the spinner, marking it as completed, and printing the
+   * final frame.
+   */
+  private _complete(prefix: string, text: string) {
+    if (this.completed) {
+      return;
+    }
+    clearInterval(this.intervalId);
+    this.printFrame(prefix, text);
+    process.stdout.write('\n');
+    this.showCursor();
+    this.completed = true;
   }
 
   /** Get the next spinner character. */
@@ -37,36 +84,46 @@ export class Spinner {
     return this.spinnerCharacters[this.currentSpinnerCharacterIndex];
   }
 
-  /** Print the current text for the spinner to the  */
-  private printFrame(prefix = this.getNextSpinnerCharacter(), text = this.text) {
+  /**
+   * Print the next frame either in CI mode or local terminal mode based on whether the script is run in a
+   * CI environment.
+   */
+  private printFrame(prefix = this.getNextSpinnerCharacter(), text?: string): void {
+    if (IS_CI) {
+      this.printNextCIFrame(text);
+    } else {
+      this.printNextLocalFrame(prefix, text);
+    }
+  }
+
+  /** Print the current text for the spinner to the terminal.  */
+  private printNextLocalFrame(prefix: string, text?: string) {
     cursorTo(process.stdout, 0);
-    process.stdout.write(` ${prefix} ${text}`);
+    process.stdout.write(` ${prefix} ${text || this.text}`);
     // Clear to the right of the cursor location in case the new frame is shorter than the previous.
     clearLine(process.stdout, 1);
-    cursorTo(process.stdout, 0);
   }
 
-  /** Updates the spinner text with the provided text. */
-  update(text: string) {
-    this.text = text;
-    this.printFrame(this.spinnerCharacters[this.currentSpinnerCharacterIndex]);
+  /** Print the next expected piece for the spinner to stdout for CI usage.  */
+  private printNextCIFrame(text?: string) {
+    if (text) {
+      process.stdout.write(`\n${text}.`);
+      return;
+    }
+    process.stdout.write('.');
   }
 
-  /** Completes the spinner. */
-  complete(): void;
-  complete(text: string): void;
-  complete(text?: string) {
-    if (!this.isRunning) {
-      return;
+  /** Hide the cursor in the terminal, only executed in local environments. */
+  private hideCursor() {
+    if (!IS_CI) {
+      process.stdout.write(hideCursor);
     }
-    clearInterval(this.intervalId);
-    clearLine(process.stdout, 1);
-    cursorTo(process.stdout, 0);
-    if (text) {
-      process.stdout.write(text);
-      process.stdout.write('\n');
+  }
+
+  /** Resume showing the cursor in the terminal, only executed in local environments. */
+  private showCursor() {
+    if (!IS_CI) {
+      process.stdout.write(showCursor);
     }
-    process.stdout.write(showCursor);
-    this.isRunning = false;
   }
 }