tailwindcss/src/lib/getModuleDependencies.js

import fs from 'fs'
import path from 'path'
import resolve from 'resolve'
import detective from 'detective'

function createModule(file) {
  const source = fs.readFileSync(file, 'utf-8')
  const requires = detective(source)

  return { file, requires }
}

export default function getModuleDependencies(entryFile) {
  const rootModule = createModule(entryFile)
  const modules = [rootModule]

  // Iterate over the modules, even when new
  // ones are being added
  for (const mdl of modules) {
    mdl.requires.forEach(dep => {
      try {
        const basedir = path.dirname(mdl.file)
        const depPath = resolve.sync(dep, { basedir })
        const depModule = createModule(depPath)

        modules.push(depModule)
      } catch (_err) {
        // eslint-disable-next-line no-empty
      }
    })
  }

  return modules
}