feat: Added /copy command for copying output to clipboard with new Command Service approach (#3706)

Co-authored-by: Abhi <43648792+abhipatel12@users.noreply.github.com>
Co-authored-by: N. Taylor Mullen <ntaylormullen@google.com>

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

@@ -0,0 +1,345 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach, Mock } from 'vitest';
+import { spawn } from 'child_process';
+import { EventEmitter } from 'events';
+import {
+  isAtCommand,
+  isSlashCommand,
+  copyToClipboard,
+} from './commandUtils.js';
+
+// Mock child_process
+vi.mock('child_process');
+
+// Mock process.platform for platform-specific tests
+const mockProcess = vi.hoisted(() => ({
+  platform: 'darwin',
+}));
+
+vi.stubGlobal('process', {
+  ...process,
+  get platform() {
+    return mockProcess.platform;
+  },
+});
+
+interface MockChildProcess extends EventEmitter {
+  stdin: EventEmitter & {
+    write: Mock;
+    end: Mock;
+  };
+  stderr: EventEmitter;
+}
+
+describe('commandUtils', () => {
+  let mockSpawn: Mock;
+  let mockChild: MockChildProcess;
+
+  beforeEach(async () => {
+    vi.clearAllMocks();
+    // Dynamically import and set up spawn mock
+    const { spawn } = await import('child_process');
+    mockSpawn = spawn as Mock;
+
+    // Create mock child process with stdout/stderr emitters
+    mockChild = Object.assign(new EventEmitter(), {
+      stdin: Object.assign(new EventEmitter(), {
+        write: vi.fn(),
+        end: vi.fn(),
+      }),
+      stderr: new EventEmitter(),
+    }) as MockChildProcess;
+
+    mockSpawn.mockReturnValue(mockChild as unknown as ReturnType<typeof spawn>);
+  });
+
+  describe('isAtCommand', () => {
+    it('should return true when query starts with @', () => {
+      expect(isAtCommand('@file')).toBe(true);
+      expect(isAtCommand('@path/to/file')).toBe(true);
+      expect(isAtCommand('@')).toBe(true);
+    });
+
+    it('should return true when query contains @ preceded by whitespace', () => {
+      expect(isAtCommand('hello @file')).toBe(true);
+      expect(isAtCommand('some text @path/to/file')).toBe(true);
+      expect(isAtCommand('   @file')).toBe(true);
+    });
+
+    it('should return false when query does not start with @ and has no spaced @', () => {
+      expect(isAtCommand('file')).toBe(false);
+      expect(isAtCommand('hello')).toBe(false);
+      expect(isAtCommand('')).toBe(false);
+      expect(isAtCommand('email@domain.com')).toBe(false);
+      expect(isAtCommand('user@host')).toBe(false);
+    });
+
+    it('should return false when @ is not preceded by whitespace', () => {
+      expect(isAtCommand('hello@file')).toBe(false);
+      expect(isAtCommand('text@path')).toBe(false);
+    });
+  });
+
+  describe('isSlashCommand', () => {
+    it('should return true when query starts with /', () => {
+      expect(isSlashCommand('/help')).toBe(true);
+      expect(isSlashCommand('/memory show')).toBe(true);
+      expect(isSlashCommand('/clear')).toBe(true);
+      expect(isSlashCommand('/')).toBe(true);
+    });
+
+    it('should return false when query does not start with /', () => {
+      expect(isSlashCommand('help')).toBe(false);
+      expect(isSlashCommand('memory show')).toBe(false);
+      expect(isSlashCommand('')).toBe(false);
+      expect(isSlashCommand('path/to/file')).toBe(false);
+      expect(isSlashCommand(' /help')).toBe(false);
+    });
+  });
+
+  describe('copyToClipboard', () => {
+    describe('on macOS (darwin)', () => {
+      beforeEach(() => {
+        mockProcess.platform = 'darwin';
+      });
+
+      it('should successfully copy text to clipboard using pbcopy', async () => {
+        const testText = 'Hello, world!';
+
+        // Simulate successful execution
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard(testText);
+
+        expect(mockSpawn).toHaveBeenCalledWith('pbcopy', []);
+        expect(mockChild.stdin.write).toHaveBeenCalledWith(testText);
+        expect(mockChild.stdin.end).toHaveBeenCalled();
+      });
+
+      it('should handle pbcopy command failure', async () => {
+        const testText = 'Hello, world!';
+
+        // Simulate command failure
+        setTimeout(() => {
+          mockChild.stderr.emit('data', 'Command not found');
+          mockChild.emit('close', 1);
+        }, 0);
+
+        await expect(copyToClipboard(testText)).rejects.toThrow(
+          "'pbcopy' exited with code 1: Command not found",
+        );
+      });
+
+      it('should handle spawn error', async () => {
+        const testText = 'Hello, world!';
+
+        setTimeout(() => {
+          mockChild.emit('error', new Error('spawn error'));
+        }, 0);
+
+        await expect(copyToClipboard(testText)).rejects.toThrow('spawn error');
+      });
+
+      it('should handle stdin write error', async () => {
+        const testText = 'Hello, world!';
+
+        setTimeout(() => {
+          mockChild.stdin.emit('error', new Error('stdin error'));
+        }, 0);
+
+        await expect(copyToClipboard(testText)).rejects.toThrow('stdin error');
+      });
+    });
+
+    describe('on Windows (win32)', () => {
+      beforeEach(() => {
+        mockProcess.platform = 'win32';
+      });
+
+      it('should successfully copy text to clipboard using clip', async () => {
+        const testText = 'Hello, world!';
+
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard(testText);
+
+        expect(mockSpawn).toHaveBeenCalledWith('clip', []);
+        expect(mockChild.stdin.write).toHaveBeenCalledWith(testText);
+        expect(mockChild.stdin.end).toHaveBeenCalled();
+      });
+    });
+
+    describe('on Linux', () => {
+      beforeEach(() => {
+        mockProcess.platform = 'linux';
+      });
+
+      it('should successfully copy text to clipboard using xclip', async () => {
+        const testText = 'Hello, world!';
+
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard(testText);
+
+        expect(mockSpawn).toHaveBeenCalledWith('xclip', [
+          '-selection',
+          'clipboard',
+        ]);
+        expect(mockChild.stdin.write).toHaveBeenCalledWith(testText);
+        expect(mockChild.stdin.end).toHaveBeenCalled();
+      });
+
+      it('should fallback to xsel when xclip fails', async () => {
+        const testText = 'Hello, world!';
+        let callCount = 0;
+
+        mockSpawn.mockImplementation(() => {
+          const child = Object.assign(new EventEmitter(), {
+            stdin: Object.assign(new EventEmitter(), {
+              write: vi.fn(),
+              end: vi.fn(),
+            }),
+            stderr: new EventEmitter(),
+          }) as MockChildProcess;
+
+          setTimeout(() => {
+            if (callCount === 0) {
+              // First call (xclip) fails
+              child.stderr.emit('data', 'xclip not found');
+              child.emit('close', 1);
+              callCount++;
+            } else {
+              // Second call (xsel) succeeds
+              child.emit('close', 0);
+            }
+          }, 0);
+
+          return child as unknown as ReturnType<typeof spawn>;
+        });
+
+        await copyToClipboard(testText);
+
+        expect(mockSpawn).toHaveBeenCalledTimes(2);
+        expect(mockSpawn).toHaveBeenNthCalledWith(1, 'xclip', [
+          '-selection',
+          'clipboard',
+        ]);
+        expect(mockSpawn).toHaveBeenNthCalledWith(2, 'xsel', [
+          '--clipboard',
+          '--input',
+        ]);
+      });
+
+      it('should throw error when both xclip and xsel fail', async () => {
+        const testText = 'Hello, world!';
+        let callCount = 0;
+
+        mockSpawn.mockImplementation(() => {
+          const child = Object.assign(new EventEmitter(), {
+            stdin: Object.assign(new EventEmitter(), {
+              write: vi.fn(),
+              end: vi.fn(),
+            }),
+            stderr: new EventEmitter(),
+          });
+
+          setTimeout(() => {
+            if (callCount === 0) {
+              // First call (xclip) fails
+              child.stderr.emit('data', 'xclip command not found');
+              child.emit('close', 1);
+              callCount++;
+            } else {
+              // Second call (xsel) fails
+              child.stderr.emit('data', 'xsel command not found');
+              child.emit('close', 1);
+            }
+          }, 0);
+
+          return child as unknown as ReturnType<typeof spawn>;
+        });
+
+        await expect(copyToClipboard(testText)).rejects.toThrow(
+          /All copy commands failed/,
+        );
+
+        expect(mockSpawn).toHaveBeenCalledTimes(2);
+      });
+    });
+
+    describe('on unsupported platform', () => {
+      beforeEach(() => {
+        mockProcess.platform = 'unsupported';
+      });
+
+      it('should throw error for unsupported platform', async () => {
+        await expect(copyToClipboard('test')).rejects.toThrow(
+          'Unsupported platform: unsupported',
+        );
+      });
+    });
+
+    describe('error handling', () => {
+      beforeEach(() => {
+        mockProcess.platform = 'darwin';
+      });
+
+      it('should handle command exit without stderr', async () => {
+        const testText = 'Hello, world!';
+
+        setTimeout(() => {
+          mockChild.emit('close', 1);
+        }, 0);
+
+        await expect(copyToClipboard(testText)).rejects.toThrow(
+          "'pbcopy' exited with code 1",
+        );
+      });
+
+      it('should handle empty text', async () => {
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard('');
+
+        expect(mockChild.stdin.write).toHaveBeenCalledWith('');
+      });
+
+      it('should handle multiline text', async () => {
+        const multilineText = 'Line 1\nLine 2\nLine 3';
+
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard(multilineText);
+
+        expect(mockChild.stdin.write).toHaveBeenCalledWith(multilineText);
+      });
+
+      it('should handle special characters', async () => {
+        const specialText = 'Special chars: !@#$%^&*()_+-=[]{}|;:,.<>?';
+
+        setTimeout(() => {
+          mockChild.emit('close', 0);
+        }, 0);
+
+        await copyToClipboard(specialText);
+
+        expect(mockChild.stdin.write).toHaveBeenCalledWith(specialText);
+      });
+    });
+  });
+});

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

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import { spawn } from 'child_process';
+
 /**
  * Checks if a query string potentially represents an '@' command.
  * It triggers if the query starts with '@' or contains '@' preceded by whitespace
@@ -24,3 +26,57 @@ export const isAtCommand = (query: string): boolean =>
  * @returns True if the query looks like an '/' command, false otherwise.
  */
 export const isSlashCommand = (query: string): boolean => query.startsWith('/');
+
+//Copies a string snippet to the clipboard for different platforms
+export const copyToClipboard = async (text: string): Promise<void> => {
+  const run = (cmd: string, args: string[]) =>
+    new Promise<void>((resolve, reject) => {
+      const child = spawn(cmd, args);
+      let stderr = '';
+      child.stderr.on('data', (chunk) => (stderr += chunk.toString()));
+      child.on('error', reject);
+      child.on('close', (code) => {
+        if (code === 0) return resolve();
+        const errorMsg = stderr.trim();
+        reject(
+          new Error(
+            `'${cmd}' exited with code ${code}${errorMsg ? `: ${errorMsg}` : ''}`,
+          ),
+        );
+      });
+      child.stdin.on('error', reject);
+      child.stdin.write(text);
+      child.stdin.end();
+    });
+
+  switch (process.platform) {
+    case 'win32':
+      return run('clip', []);
+    case 'darwin':
+      return run('pbcopy', []);
+    case 'linux':
+      try {
+        await run('xclip', ['-selection', 'clipboard']);
+      } catch (primaryError) {
+        try {
+          // If xclip fails for any reason, try xsel as a fallback.
+          await run('xsel', ['--clipboard', '--input']);
+        } catch (fallbackError) {
+          const primaryMsg =
+            primaryError instanceof Error
+              ? primaryError.message
+              : String(primaryError);
+          const fallbackMsg =
+            fallbackError instanceof Error
+              ? fallbackError.message
+              : String(fallbackError);
+          throw new Error(
+            `All copy commands failed. xclip: "${primaryMsg}", xsel: "${fallbackMsg}". Please ensure xclip or xsel is installed and configured.`,
+          );
+        }
+      }
+      return;
+    default:
+      throw new Error(`Unsupported platform: ${process.platform}`);
+  }
+};