feat: Implement /setup-github command (#5069)

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -31,6 +31,8 @@ import { statsCommand } from '../ui/commands/statsCommand.js';
 import { themeCommand } from '../ui/commands/themeCommand.js';
 import { toolsCommand } from '../ui/commands/toolsCommand.js';
 import { vimCommand } from '../ui/commands/vimCommand.js';
+import { setupGithubCommand } from '../ui/commands/setupGithubCommand.js';
+import { isGitHubRepository } from '../utils/gitUtils.js';
 
 /**
  * Loads the core, hard-coded slash commands that are an integral part
@@ -72,6 +74,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
       themeCommand,
       toolsCommand,
       vimCommand,
+      ...(isGitHubRepository() ? [setupGithubCommand] : []),
     ];
 
     return allDefinitions.filter((cmd): cmd is SlashCommand => cmd !== null);

packages/cli/src/ui/commands/setupGithubCommand.test.ts

@@ -0,0 +1,66 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, expect, it, afterEach, beforeEach } from 'vitest';
+import * as child_process from 'child_process';
+import { setupGithubCommand } from './setupGithubCommand.js';
+import { CommandContext, ToolActionReturn } from './types.js';
+
+vi.mock('child_process');
+
+describe('setupGithubCommand', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('returns a tool action to download github workflows and handles paths', () => {
+    const fakeRepoRoot = '/github.com/fake/repo/root';
+    vi.mocked(child_process.execSync).mockReturnValue(fakeRepoRoot);
+
+    const result = setupGithubCommand.action?.(
+      {} as CommandContext,
+      '',
+    ) as ToolActionReturn;
+
+    expect(result.type).toBe('tool');
+    expect(result.toolName).toBe('run_shell_command');
+    expect(child_process.execSync).toHaveBeenCalledWith(
+      'git rev-parse --show-toplevel',
+      {
+        encoding: 'utf-8',
+      },
+    );
+    expect(child_process.execSync).toHaveBeenCalledWith('git remote -v', {
+      encoding: 'utf-8',
+    });
+
+    const { command } = result.toolArgs;
+
+    const expectedSubstrings = [
+      `mkdir -p "${fakeRepoRoot}/.github/workflows"`,
+      `curl -fsSL -o "${fakeRepoRoot}/.github/workflows/gemini-cli.yml"`,
+      `curl -fsSL -o "${fakeRepoRoot}/.github/workflows/gemini-issue-automated-triage.yml"`,
+      `curl -fsSL -o "${fakeRepoRoot}/.github/workflows/gemini-issue-scheduled-triage.yml"`,
+      `curl -fsSL -o "${fakeRepoRoot}/.github/workflows/gemini-pr-review.yml"`,
+      'https://raw.githubusercontent.com/google-github-actions/run-gemini-cli/refs/heads/main/workflows/',
+    ];
+
+    for (const substring of expectedSubstrings) {
+      expect(command).toContain(substring);
+    }
+  });
+
+  it('throws an error if git root cannot be determined', () => {
+    vi.mocked(child_process.execSync).mockReturnValue('');
+    expect(() => {
+      setupGithubCommand.action?.({} as CommandContext, '');
+    }).toThrow('Unable to determine the Git root directory.');
+  });
+});

packages/cli/src/ui/commands/setupGithubCommand.ts

@@ -0,0 +1,60 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import path from 'path';
+import { execSync } from 'child_process';
+import { isGitHubRepository } from '../../utils/gitUtils.js';
+
+import {
+  CommandKind,
+  SlashCommand,
+  SlashCommandActionReturn,
+} from './types.js';
+
+export const setupGithubCommand: SlashCommand = {
+  name: 'setup-github',
+  description: 'Set up GitHub Actions',
+  kind: CommandKind.BUILT_IN,
+  action: (): SlashCommandActionReturn => {
+    const gitRootRepo = execSync('git rev-parse --show-toplevel', {
+      encoding: 'utf-8',
+    }).trim();
+
+    if (!isGitHubRepository()) {
+      throw new Error('Unable to determine the Git root directory.');
+    }
+
+    // TODO(#5198): pin workflow versions for release controls
+    const version = 'main';
+    const workflowBaseUrl = `https://raw.githubusercontent.com/google-github-actions/run-gemini-cli/refs/heads/${version}/workflows/`;
+
+    const workflows = [
+      'gemini-cli/gemini-cli.yml',
+      'issue-triage/gemini-issue-automated-triage.yml',
+      'issue-triage/gemini-issue-scheduled-triage.yml',
+      'pr-review/gemini-pr-review.yml',
+    ];
+
+    const command = [
+      'set -e',
+      `mkdir -p "${gitRootRepo}/.github/workflows"`,
+      ...workflows.map((workflow) => {
+        const fileName = path.basename(workflow);
+        return `curl -fsSL -o "${gitRootRepo}/.github/workflows/${fileName}" "${workflowBaseUrl}/${workflow}"`;
+      }),
+      'echo "Workflows downloaded successfully."',
+    ].join(' && ');
+    return {
+      type: 'tool',
+      toolName: 'run_shell_command',
+      toolArgs: {
+        description:
+          'Setting up GitHub Actions to triage issues and review PRs with Gemini.',
+        command,
+      },
+    };
+  },
+};

packages/cli/src/utils/gitUtils.ts

@@ -0,0 +1,26 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { execSync } from 'child_process';
+
+/**
+ * Checks if a directory is within a git repository hosted on GitHub.
+ * @returns true if the directory is in a git repository with a github.com remote, false otherwise
+ */
+export function isGitHubRepository(): boolean {
+  try {
+    const remotes = execSync('git remote -v', {
+      encoding: 'utf-8',
+    });
+
+    const pattern = /github\.com/;
+
+    return pattern.test(remotes);
+  } catch (_error) {
+    // If any filesystem error occurs, assume not a git repo
+    return false;
+  }
+}