Using AVA snapshots to check command output files

test-types.js

// `yarn add globby` in `endo`
// Put this file in `endo/packages/captp/test/test-types.js`
//
// `cd packages/captp` and run `yarn test test/test-types.js`
// `yarn test -u test/test-types.js` to update the snapshots
//
// Snapshots are kept in test/snapshots/*
import test from 'ava';
import fs from 'node:fs';
import { spawn } from 'node:child_process';
import path from 'node:path';
import { globby } from 'globby';

const pspawn = (cmd, args, { logFile, ...opts } = {}) =>
  new Promise(resolve => {
    const proc = spawn(cmd, args, opts);
    if (logFile) {
      proc.stdout.on('data', data => fs.appendFileSync(logFile, data));
      proc.stderr.on('data', data => fs.appendFileSync(logFile, data));
    }
    proc.on('close', code => resolve(code));
  });

const annoType = async (...args) => {
  let tmpdir;
  try {
    tmpdir = await fs.promises.mkdtemp('anno-type-');
    const logFile = path.join(tmpdir, 'anno-type.log');
    await fs.promises.writeFile(`${logFile}.js`, `// timestamp: ${Date.now()}\n`); // REMOVE
    const code = await pspawn(
      '/bin/echo', // 'yarn'
      ['anno-type', '-abc', `--output=${tmpdir}`, ...args],
      { logFile, cwd: process.cwd(), stdio: ['ignore', 'pipe', 'pipe'] }
    );
    if (code !== 0) {
      throw Error(`anno-type exited with code ${code}`);
    }
  } catch (e) {
    // Keep the temporary directory around for debugging.
    console.error(`Error executing with output in ${tmpdir}:`, e);
    throw e;
  }
  return tmpdir;
};

const compareGlob = async (t, dir, patterns, desc) => {
  const d = desc ? txt => `${txt}: ${desc}` : txt => txt;
  const files = await globby(patterns.map(pat => path.posix.join(dir, pat)));
  const relents = files.sort().map(f => [f, path.posix.relative(dir, f)]);
  t.snapshot(relents.map(([_k, v]) => v), d(`output filenames`));
  for (const [file, relfile] of relents) {
    const buf = await fs.promises.readFile(file);
    const content = buf.toString('utf-8');
    t.snapshot(content, d(`content of ${relfile}`));
  }
};

test('check something', async t => {
  const tmpDir = await annoType('foo', 'bar');
  await compareGlob(t, tmpDir, ['**/*.js'], `foo and bar`);
  await fs.promises.rm(tmpDir, { recursive: true });
});