Function lessProcessor

packages/vite/src/node/plugins/css.ts:2925–2984

(
  maxWorkers: number | undefined,
)

}

const lessProcessor = (
  maxWorkers: number | undefined,
): StylePreprocessor<LessStylePreprocessorInternalOptions> => {
  let worker: ReturnType<typeof makeLessWorker> | undefined

  return {
    close() {
      worker?.stop()
    },
    async process(environment, source, root, options, resolvers) {
      const lessPath = loadPreprocessorPath(PreprocessLang.less, root)
      worker ??= makeLessWorker(environment, resolvers, maxWorkers)

      const { content, map: additionalMap } = await getSource(
        source,
        options.filename,
        options.additionalData,
        options.enableSourcemap,
      )

      let result: Less.RenderOutput | undefined
      const optionsWithoutAdditionalData = {
        ...options,
        additionalData: undefined,
      }
      try {
        result = await worker.run(
          pathToFileURL(lessPath).href,
          content,
          optionsWithoutAdditionalData,
        )
      } catch (e) {
        const error = e as Less.RenderError
        // normalize error info
        const normalizedError: RollupError = new Error(
          `[less] ${error.message || error.type}`,
        ) as RollupError
        normalizedError.loc = {
          file: error.filename || options.filename,
          line: error.line,
          column: error.column,
        }
        return { code: '', error: normalizedError, deps: [] }
      }

      const map: ExistingRawSourceMap | undefined =
        result.map && JSON.parse(result.map)
      if (map) {
        delete map.sourcesContent
      }

      return {
        code: result.css.toString(),
        map,
        additionalMap,
        deps: result.imports,
      }
    },