Function withEnv

test/mailboxStore.test.js:15–24

(name, value, fn)

}

function withEnv(name, value, fn) {
  const saved = process.env[name];
  process.env[name] = value;
  try {
    return fn();
  } finally {
    if (saved === undefined) delete process.env[name];
    else process.env[name] = saved;
  }
}

function withFixedNow(now, fn) {
  const originalNow = Date.now;