feat: add Rewind Confirmation dialog and Rewind Viewer component (#15717)

packages/cli/src/ui/utils/formatters.test.ts

@@ -4,8 +4,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect } from 'vitest';
-import { formatDuration, formatMemoryUsage } from './formatters.js';
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import {
+  formatDuration,
+  formatMemoryUsage,
+  formatTimeAgo,
+  stripReferenceContent,
+} from './formatters.js';
 
 describe('formatters', () => {
   describe('formatMemoryUsage', () => {
@@ -69,4 +74,93 @@ describe('formatters', () => {
       expect(formatDuration(-100)).toBe('0s');
     });
   });
+
+  describe('formatTimeAgo', () => {
+    const NOW = new Date('2025-01-01T12:00:00Z');
+
+    beforeEach(() => {
+      vi.useFakeTimers();
+      vi.setSystemTime(NOW);
+    });
+
+    afterEach(() => {
+      vi.useRealTimers();
+    });
+
+    it('should return "just now" for dates less than a minute ago', () => {
+      const past = new Date(NOW.getTime() - 30 * 1000);
+      expect(formatTimeAgo(past)).toBe('just now');
+    });
+
+    it('should return minutes ago', () => {
+      const past = new Date(NOW.getTime() - 5 * 60 * 1000);
+      expect(formatTimeAgo(past)).toBe('5m ago');
+    });
+
+    it('should return hours ago', () => {
+      const past = new Date(NOW.getTime() - 3 * 60 * 60 * 1000);
+      expect(formatTimeAgo(past)).toBe('3h ago');
+    });
+
+    it('should return days ago', () => {
+      const past = new Date(NOW.getTime() - 2 * 24 * 60 * 60 * 1000);
+      expect(formatTimeAgo(past)).toBe('48h ago');
+    });
+
+    it('should handle string dates', () => {
+      const past = '2025-01-01T11:00:00Z'; // 1 hour ago
+      expect(formatTimeAgo(past)).toBe('1h ago');
+    });
+
+    it('should handle number timestamps', () => {
+      const past = NOW.getTime() - 10 * 60 * 1000; // 10 minutes ago
+      expect(formatTimeAgo(past)).toBe('10m ago');
+    });
+    it('should handle invalid timestamps', () => {
+      const past = 'hello';
+      expect(formatTimeAgo(past)).toBe('invalid date');
+    });
+  });
+
+  describe('stripReferenceContent', () => {
+    it('should return the original text if no markers are present', () => {
+      const text = 'Hello world';
+      expect(stripReferenceContent(text)).toBe(text);
+    });
+
+    it('should strip content between markers', () => {
+      const text =
+        'Prompt @file.txt\n--- Content from referenced files ---\nFile content here\n--- End of content ---';
+      expect(stripReferenceContent(text)).toBe('Prompt @file.txt');
+    });
+
+    it('should strip content and keep text after the markers', () => {
+      const text =
+        'Before\n--- Content from referenced files ---\nMiddle\n--- End of content ---\nAfter';
+      expect(stripReferenceContent(text)).toBe('Before\nAfter');
+    });
+
+    it('should handle missing end marker gracefully', () => {
+      const text = 'Before\n--- Content from referenced files ---\nMiddle';
+      expect(stripReferenceContent(text)).toBe(text);
+    });
+
+    it('should handle end marker before start marker gracefully', () => {
+      const text =
+        '--- End of content ---\n--- Content from referenced files ---';
+      expect(stripReferenceContent(text)).toBe(text);
+    });
+
+    it('should strip even if markers are on the same line (though unlikely)', () => {
+      const text =
+        'A--- Content from referenced files ---B--- End of content ---C';
+      expect(stripReferenceContent(text)).toBe('AC');
+    });
+
+    it('should strip multiple blocks correctly and preserve text in between', () => {
+      const text =
+        'Start\n--- Content from referenced files ---\nBlock1\n--- End of content ---\nMiddle\n--- Content from referenced files ---\nBlock2\n--- End of content ---\nEnd';
+      expect(stripReferenceContent(text)).toBe('Start\nMiddle\nEnd');
+    });
+  });
 });

packages/cli/src/ui/utils/formatters.ts

@@ -61,3 +61,37 @@ export const formatDuration = (milliseconds: number): string => {
 
   return parts.join(' ');
 };
+
+export const formatTimeAgo = (date: string | number | Date): string => {
+  const past = new Date(date);
+  if (isNaN(past.getTime())) {
+    return 'invalid date';
+  }
+
+  const now = new Date();
+  const diffMs = now.getTime() - past.getTime();
+  if (diffMs < 60000) {
+    return 'just now';
+  }
+  return `${formatDuration(diffMs)} ago`;
+};
+
+const REFERENCE_CONTENT_START = '--- Content from referenced files ---';
+const REFERENCE_CONTENT_END = '--- End of content ---';
+
+/**
+ * Removes content bounded by reference content markers from the given text.
+ * The markers are "--- Content from referenced files ---" and "--- End of content ---".
+ *
+ * @param text The input text containing potential reference blocks.
+ * @returns The text with reference blocks removed and trimmed.
+ */
+export function stripReferenceContent(text: string): string {
+  // Match optional newline, the start marker, content (non-greedy), and the end marker
+  const pattern = new RegExp(
+    `\\n?${REFERENCE_CONTENT_START}[\\s\\S]*?${REFERENCE_CONTENT_END}`,
+    'g',
+  );
+
+  return text.replace(pattern, '').trim();
+}