feat(chat): Implement /chat delete command (#2401)

packages/core/src/core/logger.test.ts

@@ -490,6 +490,68 @@ describe('Logger', () => {
     });
   });
 
+  describe('deleteCheckpoint', () => {
+    const conversation: Content[] = [
+      { role: 'user', parts: [{ text: 'Content to be deleted' }] },
+    ];
+    const tag = 'delete-me';
+    let taggedFilePath: string;
+
+    beforeEach(async () => {
+      taggedFilePath = path.join(
+        TEST_GEMINI_DIR,
+        `${CHECKPOINT_FILE_NAME.replace('.json', '')}-${tag}.json`,
+      );
+      // Create a file to be deleted
+      await fs.writeFile(taggedFilePath, JSON.stringify(conversation));
+    });
+
+    it('should delete the specified checkpoint file and return true', async () => {
+      const result = await logger.deleteCheckpoint(tag);
+      expect(result).toBe(true);
+
+      // Verify the file is actually gone
+      await expect(fs.access(taggedFilePath)).rejects.toThrow(/ENOENT/);
+    });
+
+    it('should return false if the checkpoint file does not exist', async () => {
+      const result = await logger.deleteCheckpoint('non-existent-tag');
+      expect(result).toBe(false);
+    });
+
+    it('should re-throw an error if file deletion fails for reasons other than not existing', async () => {
+      // Simulate a different error (e.g., permission denied)
+      vi.spyOn(fs, 'unlink').mockRejectedValueOnce(
+        new Error('EACCES: permission denied'),
+      );
+      const consoleErrorSpy = vi
+        .spyOn(console, 'error')
+        .mockImplementation(() => {});
+
+      await expect(logger.deleteCheckpoint(tag)).rejects.toThrow(
+        'EACCES: permission denied',
+      );
+      expect(consoleErrorSpy).toHaveBeenCalledWith(
+        `Failed to delete checkpoint file ${taggedFilePath}:`,
+        expect.any(Error),
+      );
+    });
+
+    it('should return false if logger is not initialized', async () => {
+      const uninitializedLogger = new Logger(testSessionId);
+      uninitializedLogger.close();
+      const consoleErrorSpy = vi
+        .spyOn(console, 'error')
+        .mockImplementation(() => {});
+
+      const result = await uninitializedLogger.deleteCheckpoint(tag);
+      expect(result).toBe(false);
+      expect(consoleErrorSpy).toHaveBeenCalledWith(
+        'Logger not initialized or checkpoint file path not set. Cannot delete checkpoint.',
+      );
+    });
+  });
+
   describe('close', () => {
     it('should reset logger state', async () => {
       await logger.logMessage(MessageSenderType.USER, 'A message');

packages/core/src/core/logger.ts

@@ -292,6 +292,30 @@ export class Logger {
     }
   }
 
+  async deleteCheckpoint(tag: string): Promise<boolean> {
+    if (!this.initialized || !this.geminiDir) {
+      console.error(
+        'Logger not initialized or checkpoint file path not set. Cannot delete checkpoint.',
+      );
+      return false;
+    }
+
+    const path = this._checkpointPath(tag);
+
+    try {
+      await fs.unlink(path);
+      return true;
+    } catch (error) {
+      const nodeError = error as NodeJS.ErrnoException;
+      if (nodeError.code === 'ENOENT') {
+        // File doesn't exist, which is fine.
+        return false;
+      }
+      console.error(`Failed to delete checkpoint file ${path}:`, error);
+      throw error;
+    }
+  }
+
   close(): void {
     this.initialized = false;
     this.logFilePath = undefined;