Function resolvePostcssConfig

packages/vite/src/node/plugins/css.ts:1944–1993

(
  config: ResolvedConfig,
)

}

async function resolvePostcssConfig(
  config: ResolvedConfig,
): Promise<PostCSSConfigResult | null> {
  let result = postcssConfigCache.get(config)
  if (result !== undefined) {
    return await result
  }

  // inline postcss config via vite config
  const inlineOptions = config.css.postcss
  if (isObject(inlineOptions)) {
    const options = { ...inlineOptions }

    delete options.plugins
    result = {
      options,
      plugins: inlineOptions.plugins || [],
    }
  } else {
    const searchPath =
      typeof inlineOptions === 'string' ? inlineOptions : config.root
    const stopDir = searchForWorkspaceRoot(config.root)
    result = postcssrc({}, searchPath, { stopDir }).catch((e) => {
      if (!e.message.includes('No PostCSS Config found')) {
        if (e instanceof Error) {
          const { name, message, stack } = e
          e.name = 'Failed to load PostCSS config'
          e.message = `Failed to load PostCSS config (searchPath: ${searchPath}): [${name}] ${message}\n${stack}`
          e.stack = '' // add stack to message to retain stack
          throw e
        } else {
          throw new Error(`Failed to load PostCSS config: ${e}`)
        }
      }
      return null
    })
    // replace cached promise to result object when finished
    result.then(
      (resolved) => {
        postcssConfigCache.set(config, resolved)
      },
      () => {
        /* keep as rejected promise, will be handled later */
      },
    )
  }

  postcssConfigCache.set(config, result)
  return result
}

type CssUrlResolver = (
  url: string,