Function startedOnPort

playground/cli/__tests__/serve.ts:120–145

(serverProcess, port, timeout)

// helper to validate that server was started on the correct port
async function startedOnPort(serverProcess, port, timeout) {
  let checkPort
  const startedPromise = new Promise<void>((resolve, reject) => {
    checkPort = (data) => {
      const str = stripVTControlCharacters(data.toString())
      const match = str.match(
        /http:\/\/(?:localhost|127\.0\.0\.1|\[::1\]):(\d{4})/,
      )
      if (match) {
        const startedPort = parseInt(match[1], 10)
        if (startedPort === port) {
          resolve()
        } else {
          const msg = `server listens on port ${startedPort} instead of ${port}`
          reject(msg)
        }
      }
    }
    serverProcess.stdout.on('data', checkPort)
  })
  return resolvedOrTimeout(
    startedPromise,
    timeout,
    `failed to start within ${timeout}ms`,
  ).finally(() => serverProcess.stdout.off('data', checkPort))
}

// helper function that rejects with errorMessage if promise isn't settled within ms
async function resolvedOrTimeout(promise, ms, errorMessage) {