index.js

const core = require("@actions/core");
const github = require("@actions/github");
const { Octokit } = require("@octokit/action");
const exec = require("@actions/exec");

const { spawnSync } = require("child_process");

(async () => {
  try {
    const prettierCommand = core.getInput("prettier_command");

    const pullRequestNumber = github.context.payload.issue.number;
    const commentBody = github.context.payload.comment.body;

    // /p とか /pre とか /prettier とか /pretier (つづりミス) などにマッチ
    const commandRegexp = new RegExp("^/p(ret?t?i?e?r?)?$");

    if (!commentBody || !commandRegexp.test(commentBody.trim())) {
      console.log("skip.");
      return;
    }

    const octokit = new Octokit();

    const owner = github.context.repo.owner;
    const repo = github.context.repo.repo;

    octokit.reactions.createForIssueComment({
      owner,
      repo,
      comment_id: github.context.payload.comment.id,
      content: "+1",
    });

    const { data } = await octokit.pulls.get({
      owner,
      repo,
      pull_number: pullRequestNumber,
    });

    const branch = data.head.ref;

    await exec.exec(`git fetch origin ${branch} --depth 1`);
    await exec.exec(`git switch ${branch}`);

    // todo: paginate
    const { data: fileList } = await octokit.pulls.listFiles({
      owner,
      repo,
      pull_number: pullRequestNumber,
    });

    const files = fileList.map((s) => s.filename);
    console.log("target files:", files);

    // todo: inputs.glob

    const command = `${prettierCommand} ${files.join(" ")}`;
    console.log("run command:", command);

    // actions/exec のほうが良いかも
    const { status, error, stdout, stderr } = spawnSync(command, {
      shell: true,
    });

    // 処理できなかったファイルとかあると止まる
    // if (status !== 0 || status !== 1) {
    //   if (error) {
    //     throw error
    //   }
    // }

    if (error) {
      console.error(error);
    }

    const cmdOutput = stdout.toString();
    console.log(cmdOutput);

    // create PR comment
    const body = `prettier executed. (exit with status ${status})\n\n${cmdOutput}`;

    await octokit.pulls.createReview({
      owner,
      repo,
      pull_number: pullRequestNumber,
      body: body,
      event: "COMMENT",
    });

    if (stderr) {
      console.log("stderr", stderr);
    }

    if (error) {
      const body = `error: ${error}`;
      await octokit.pulls.createReview({
        owner,
        repo,
        pull_number: pullRequestNumber,
        body: body,
        event: "COMMENT",
      });
    }
  } catch (error) {
    core.setFailed(error.message);
  }
})();