wxss-transpiler/index.js

const postcss = require('postcss')
const wxssPlugin = require('postcss-wxss')
const fs = require('fs')
const path = require('path')

const importRegx = /@import\s+(?:'(.+\.wxss)'|"(.+\.wxss)");?/g

let fileStack = []

const constructPath = function (file) {
  const lastFile = fileStack.slice(-1)[0]
  let dir
  if (lastFile) {
    dir = path.dirname(lastFile)
  } else {
    dir = process.cwd()
  }
  const fullPath = path.resolve(dir, file)

  if (fileStack.indexOf(fullPath) === -1) {
    fileStack.push(fullPath)
  } else {
    throw new Error('Circular Import')
  }
  return fullPath
}

const getContent = function (file) {
  const content = fs.readFileSync(constructPath(file))
  return content.toString().replace(importRegx, function (str, p1, p2) {
    const childPath = p1 || p2
    const res = getContent(childPath)
    fileStack.pop()
    return res
  })
}

module.exports = function (files, opts) {
  fileStack = []
  const fileList = files.slice()
  const initFile = fileList.shift()
  const cssSource = getContent(initFile)
  return postcss([wxssPlugin(opts)])
    .process(cssSource)
    .then(res => res.css)
    .catch(err => console.log('postcss err:', err))
}