Build a feature from an issue with an AI agent

import { readFile } from 'node:fs/promises';

const repository = process.env.GITHUB_REPOSITORY;
const token = process.env.GITHUB_TOKEN;

if (!repository || !token) {
  console.error(
    'GITHUB_REPOSITORY or GITHUB_TOKEN is not set. Add both to the preview environment of the EAS project.'
  );
  process.exit(1);
}

async function request(method, path, body) {
  const response = await fetch(`https://api.github.com${path}`, {
    method,
    headers: {
      accept: 'application/vnd.github+json',
      authorization: `Bearer ${token}`,
      'content-type': 'application/json',
      'x-github-api-version': '2022-11-28',
    },
    body: body ? JSON.stringify(body) : undefined,
  });
  if (!response.ok) {
    throw new Error(
      `GitHub returned ${response.status} for ${method} ${path}: ${await response.text()}\nCheck that GITHUB_TOKEN can read and write contents, issues, and pull requests in ${repository}.`
    );
  }
  return response.json();
}

const repo = `/repos/${repository}`;
const [command, ...args] = process.argv.slice(2);

switch (command) {
  case 'issue': {
    const issue = await request('GET', `${repo}/issues/${args[0]}`);
    const comments = await request('GET', `${repo}/issues/${args[0]}/comments?per_page=50`);
    console.log(
      JSON.stringify(
        {
          title: issue.title,
          body: issue.body,
          comments: comments
            .filter(comment =>
              ['OWNER', 'MEMBER', 'COLLABORATOR'].includes(comment.author_association)
            )
            .map(comment => comment.body),
        },
        null,
        2
      )
    );
    break;
  }
  case 'comment': {
    await request('POST', `${repo}/issues/${args[0]}/comments`, {
      body: await readFile(args[1], 'utf8'),
    });
    break;
  }
  case 'open-pull-request': {
    const [branch, title, bodyFile] = args;
    const owner = repository.split('/')[0];
    const open = await request('GET', `${repo}/pulls?state=open&head=${owner}:${branch}`);
    if (open.length > 0) {
      console.log(open[0].html_url);
      break;
    }
    const { default_branch: base } = await request('GET', repo);
    const pullRequest = await request('POST', `${repo}/pulls`, {
      head: branch,
      base,
      title,
      body: await readFile(bodyFile, 'utf8'),
    });
    console.log(pullRequest.html_url);
    break;
  }
  case 'author-email': {
    const user = await request('GET', '/user');
    console.log(`${user.id}+${user.login}@users.noreply.github.com`);
    break;
  }
  default:
    console.error(
      `Unknown command "${command}". Use issue, comment, open-pull-request, or author-email.`
    );
    process.exit(1);
}

#!/usr/bin/env bash
set -euo pipefail

: "${ISSUE_NUMBER:?No issue number. Pass -F issue_number=<number>.}"
: "${GITHUB_TOKEN:?GITHUB_TOKEN is not set. Add it to the preview environment.}"
: "${GITHUB_REPOSITORY:?GITHUB_REPOSITORY is not set. Add it to the preview environment.}"

PROJECT_DIR=$(pwd)
REPO_DIR=$(git rev-parse --show-toplevel)
APP_PATH=$(git rev-parse --show-prefix)
WORK_DIR=/tmp/agent-change
APP_DIR="$WORK_DIR/$APP_PATH"
BRANCH="agent/issue-$ISSUE_NUMBER"
GITHUB_HELPER="$PROJECT_DIR/.eas/agents/github.mjs"
PUSH_URL="https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git"

git clone --depth 1 "$PUSH_URL" "$WORK_DIR"
git -C "$WORK_DIR" remote set-url origin "https://github.com/${GITHUB_REPOSITORY}.git"
ln -s "$REPO_DIR/node_modules" "$WORK_DIR/node_modules"
printf 'node_modules\nagent-output/\n' >> "$WORK_DIR/.git/info/exclude"
mkdir -p "$APP_DIR/agent-output"

{
  cat .eas/agents/make-change.md
  printf '\n## Issue #%s\n\n' "$ISSUE_NUMBER"
  node "$GITHUB_HELPER" issue "$ISSUE_NUMBER"
} > "$APP_DIR/agent-output/prompt.md"

cd "$APP_DIR"
env -u EXPO_TOKEN -u EXPO_TOKEN_SIMULATOR -u GITHUB_TOKEN \
  timeout 20m bash .eas/agents/run-agent.sh agent-output/prompt.md change || true

if [ -n "$(git -C "$WORK_DIR" status --porcelain -- "${APP_PATH}.eas" .github)" ]; then
  echo "The agent changed files in .eas or .github. The job does not open a pull request." >&2
  exit 1
fi

if [ -z "$(git status --porcelain)" ]; then
  {
    printf '## Issue to PR\n\nThe agent did not change any file.\n\n'
    cat agent-output/summary.md 2> /dev/null || true
  } > /tmp/comment.md
  node "$GITHUB_HELPER" comment "$ISSUE_NUMBER" /tmp/comment.md
  exit 1
fi

TITLE=$(head -n 1 agent-output/summary.md 2> /dev/null || true)
TITLE=${TITLE:-"Change for issue #$ISSUE_NUMBER"}
{
  tail -n +2 agent-output/summary.md 2> /dev/null || true
  printf '\n\nCloses #%s\n' "$ISSUE_NUMBER"
} > /tmp/pull-request.md

AUTHOR_EMAIL=$(node "$GITHUB_HELPER" author-email)
git checkout -b "$BRANCH"
git add -A
git -c user.name="EAS agent" -c user.email="$AUTHOR_EMAIL" commit -m "$TITLE"
git push --force "$PUSH_URL" "HEAD:refs/heads/$BRANCH"
PR_URL=$(node "$GITHUB_HELPER" open-pull-request "$BRANCH" "$TITLE" /tmp/pull-request.md)

printf '## Issue to PR\n\nThe agent opened %s.\n' "$PR_URL" > /tmp/comment.md
node "$GITHUB_HELPER" comment "$ISSUE_NUMBER" /tmp/comment.md

You make one change in this Expo project. The issue at the end of this prompt describes the change.

1. Read the issue and its comments.
2. Make the smallest change that does what the issue asks. Use the style of the code around the change.
3. Do not add dependencies. Do not change files in .eas, .github, or node_modules.
4. If the project has a tsconfig.json file, run `npx tsc --noEmit`. Fix each error that your change causes. Do not fix errors that were there before your change.
5. Write the file agent-output/summary.md. Line 1 is a pull request title. Then describe the change in two to five sentences. Tell what a user sees, because Agentic CI tests that.

If you cannot make the change, do not change any file. Then write line 1 of agent-output/summary.md as "No change: <reason>".

name: Issue to PR

on:
  workflow_dispatch:
    inputs:
      issue_number:
        description: The number of the issue that the agent works on
        type: string
        required: true

jobs:
  change:
    environment: preview
    env:
      ISSUE_NUMBER: ${{ inputs.issue_number }}
    steps:
      - uses: eas/checkout
      - uses: eas/install_node_modules
      - name: Make the change and open a pull request
        run: bash .eas/agents/make-change.sh
      - uses: eas/upload_artifact
        if: ${{ always() }}
        with:
          type: other
          name: issue-to-pr-log
          path: /tmp/agent-change/agent-output/**/*

name: Start the agent

on:
  issues:
    types: [labeled]

jobs:
  start:
    if: github.event.label.name == 'agent'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v5
      - uses: actions/setup-node@v5
        with:
          node-version: 22
      - run: npm ci
      - run: npx --yes eas-cli@latest workflow:run .eas/workflows/issue-to-pr.yml --ref ${{ github.sha }} -F issue_number=${{ github.event.issue.number }} --non-interactive
        env:
          EXPO_TOKEN: ${{ secrets.EXPO_TOKEN }}