perf: optimize logger

packages/vite/src/node/logger.ts

@@ -51,6 +51,18 @@ export interface LoggerOptions {
  customLogger?: Logger
 }
 
+// Only initialize the timeFormatter when the timestamp option is used, and
+// reuse it across all loggers
+let timeFormatter: Intl.DateTimeFormat
+function getTimeFormatter() {
+ timeFormatter ??= new Intl.DateTimeFormat(undefined, {
+ hour: 'numeric',
+ minute: 'numeric',
+ second: 'numeric',
+ })
+ return timeFormatter
+}
+
 export function createLogger(
  level: LogLevel = 'info',
  options: LoggerOptions = {},
@@ -59,53 +71,55 @@ export function createLogger(
  return options.customLogger
  }
 
- const timeFormatter = new Intl.DateTimeFormat(undefined, {
- hour: 'numeric',
- minute: 'numeric',
- second: 'numeric',
- })
  const loggedErrors = new WeakSet<Error | RollupError>()
  const { prefix = '[vite]', allowClearScreen = true } = 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) {
+ const tag =
+ type === 'info'
+ ? colors.cyan(colors.bold(prefix))
+ : type === 'warn'
+ ? colors.yellow(colors.bold(prefix))
+ : colors.red(colors.bold(prefix))
+ return `${colors.dim(
+ getTimeFormatter().format(new Date()),
+ )} ${tag} ${msg}`
+ } else {
+ return msg
+ }
+ }
+
  function output(type: LogType, msg: string, options: LogErrorOptions = {}) {
  if (thresh >= LogLevels[type]) {
  const method = type === 'info' ? 'log' : type
- const format = () => {
- if (options.timestamp) {
- const tag =
- type === 'info'
- ? colors.cyan(colors.bold(prefix))
- : type === 'warn'
- ? colors.yellow(colors.bold(prefix))
- : colors.red(colors.bold(prefix))
- return `${colors.dim(timeFormatter.format(new Date()))} ${tag} ${msg}`
- } else {
- return msg
- }
- }
+
  if (options.error) {
  loggedErrors.add(options.error)
  }
  if (canClearScreen) {
  if (type === lastType && msg === lastMsg) {
  sameCount++
  clear()
- console[method](format(), colors.yellow(`(x${sameCount + 1})`))
+ console[method](
+ format(type, msg, options),
+ colors.yellow(`(x${sameCount + 1})`),
+ )
  } else {
  sameCount = 0
  lastMsg = msg
  lastType = type
  if (options.clear) {
  clear()
  }
- console[method](format())
+ console[method](format(type, msg, options))
  }
  } else {
- console[method](format())
+ console[method](format(type, msg, options))
  }
  }
  }