als-require/lib/get-contents.js

A utility for using CommonJS require in the browser and creating bundles.

const rootPath = process.cwd()
const fs = require('fs'), { join } = require('path');
const getFullPath = require('./get-full-path')
const getNodeModules = require('./node-modules')

function getContents({ contents, fullPath }, Require, cyclicDependencies, logger, plugins) {
   const getContent = (path) => {
      if (contents[path] !== undefined) return // allready fetched
      if (!Require.contents[path]) {
         let content = fs.readFileSync(join(rootPath, path), 'utf-8')
         const children = []
         content = content.replace(/^(?!\/\/|\/\*.*\*\/).*require\(["'`](.*)["'`]\)/gm, (match, modulePath) => {
            let fullPath
            const r = new RegExp(`require\\((["'\`])${modulePath}["'\`]\\)`)
            if (modulePath.startsWith('.')) fullPath = getFullPath(modulePath, path)
            else {
               fullPath = getNodeModules(modulePath, logger)
               if (fullPath === false) return match.replace(r, '{}')
            }
            if (!cyclicDependencies && Require.contents[fullPath] && Require.contents[fullPath].children.includes(path)) {
               throw `Cyclic dependency between ${path} and ${fullPath}`
            }
            children.push(fullPath);
            return match.replace(r, (m, quoute) => `require(${quoute}${fullPath}${quoute})`)
         });
         Require.contents[path] = { content, children }
      }
      let { content, children } = Require.contents[path]
      const obj = {content,children,path}
      plugins.forEach(plugin => { plugin(obj) });
      contents[path] = obj.content
      for (let childPath of children) {
         getContent(childPath)
      }
   }

   getContent(fullPath)
}

module.exports = getContents