Function scanImports

packages/vite/src/node/optimizer/scan.ts:116–207

(environment: ScanEnvironment)

  /(?<!\/\/.*)(?<=^|;|\*\/)\s*import(?!\s+type)(?:[\w*{}\n\r\t, ]+from)?\s*("[^"]+"|'[^']+')\s*(?=$|;|\/\/|\/\*)/gm

export function scanImports(environment: ScanEnvironment): {
  cancel: () => Promise<void>
  result: Promise<{
    deps: Record<string, string>
    missing: Record<string, string>
  }>
} {
  const start = performance.now()
  const { config } = environment

  const scanContext = { cancelled: false }
  async function cancel() {
    scanContext.cancelled = true
  }

  async function scan() {
    const entries = await computeEntries(environment)
    if (!entries.length) {
      if (!config.optimizeDeps.entries && !config.optimizeDeps.include) {
        environment.logger.warn(
          colors.yellow(
            '(!) Could not auto-determine entry point from rolldownOptions or html files ' +
              'and there are no explicit optimizeDeps.include patterns. ' +
              'Skipping dependency pre-bundling.',
          ),
        )
      }
      return
    }
    if (scanContext.cancelled) return

    debug?.(
      `Crawling dependencies using entries: ${entries
        .map((entry) => `\n  ${colors.dim(entry)}`)
        .join('')}`,
    )
    const deps: Record<string, string> = {}
    const missing: Record<string, string> = {}

    const context = await prepareRolldownScanner(
      environment,
      entries,
      deps,
      missing,
    )
    if (scanContext.cancelled) return

    try {
      await context.build()
      return {
        // Ensure a fixed order so hashes are stable and improve logs
        deps: orderedDependencies(deps),
        missing,
      }
    } catch (e) {
      // The scanner runs in the background and may still be crawling when the
      // server is closed. In that case resolutions reject with
      // `ERR_CLOSED_SERVER` and the scan build fails.