Function createLogger

packages/vite/src/node/logger.ts:68–166

(
  level: LogLevel = 'info',
  options: LoggerOptions = {},
)

}

export function createLogger(
  level: LogLevel = 'info',
  options: LoggerOptions = {},
): Logger {
  if (options.customLogger) {
    return options.customLogger
  }

  const loggedErrors = new WeakSet<Error | RollupError>()
  const {
    prefix = '[vite]',
    allowClearScreen = true,
    console = globalThis.console,
  } = options
  const thresh = LogLevels[level]
  const canClearScreen =
    allowClearScreen && process.stdout.isTTY && !process.env.CI
  const clear = canClearScreen ? clearScreen : () => {}

  function format(type: LogType, msg: string, options: LogErrorOptions = {}) {
    if (options.timestamp) {
      let tag = ''
      if (type === 'info') {
        tag = colors.cyan(colors.bold(prefix))
      } else if (type === 'warn') {
        tag = colors.yellow(colors.bold(prefix))
      } else {
        tag = colors.red(colors.bold(prefix))
      }
      const environment = options.environment ? options.environment + ' ' : ''
      return `${colors.dim(getTimeFormatter().format(new Date()))} ${tag} ${environment}${msg}`
    } else {
      return msg
    }
  }

  function output(type: LogType, msg: string, options: LogErrorOptions = {}) {
    if (thresh >= LogLevels[type]) {
      const method = type === 'info' ? 'log' : type

      if (options.error) {
        loggedErrors.add(options.error)
      }
      if (canClearScreen) {
        if (type === lastType && msg === lastMsg) {
          sameCount++
          clear()
          console[method](
            format(type, msg, options),
            colors.yellow(`(x${sameCount + 1})`),
          )
        } else {
          sameCount = 0
          lastMsg = msg
          lastType = type
          if (options.clear) {
            clear()
          }