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

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,
+      },
+    };
+  },
+};