Detects unused files in Next.js

detect-unused

// grab all the files in src/

import { glob } from 'glob'
import { basename, extname } from 'node:path'

function getName(a: string) {
  return basename(a, extname(a))
}

function isSameFileName(fpA, fpB) {
  if (fpA === fpB) return false // same file
  const fileNameA = getName(fpA)
  const fileNameB = getName(fpB)

  if (fileNameA === fileNameB) {
    // if it's "index.ts" or "index.js" then it's not a conflict, check the folder above also
    if (fileNameA === 'index.ts' || fileNameA === 'index.js') {
      const folderA = fpA.split('/').slice(0, -1).join('/')
      const folderB = fpB.split('/').slice(0, -1).join('/')
      return folderA === folderB
    }
    return true
  }
}
const fileContents = {}
function findFileName(file: string, filePaths: string[]) {
  for (const otherFilePath of filePaths) {
    if (file === otherFilePath) continue
    if (fileContents[otherFilePath].includes(file.replace(/^(app|components|lib|hooks)\//, '@/'))) {
      return true
    }
    const fileName = file.split('/').pop()
    if (fileContents[otherFilePath].includes(fileName)) {
      return true
    }
    // without extension
    const fileNameWithoutExtension = fileName.split('.')[0]
    if (fileContents[otherFilePath].includes(fileNameWithoutExtension)) {
      return true
    }
  }
  return false
}

async function checkUnusedDependencies(filePaths: string[]) {
  // for all our files, check if they are imported in any other file
  // if not, then it's an unused dependency

  const unusedDependencies = []
  // filenames
  for (const filePath of filePaths) {
    const isFound = findFileName(filePath, filePaths)
    if (!isFound) {
      unusedDependencies.push(filePath)
    }
  }

  if (unusedDependencies.length > 0) {
    console.log('Found unused dependencies:')
  }
  for (const unusedDependency of unusedDependencies) {
    console.log(unusedDependency)
  }
  if (unusedDependencies.length > 0) {
    process.exit(1)
  }
}

async function main() {
  const filePaths = await glob([
    '{app,components,lib,hooks}/**/*.{ts,tsx,vue,js,json}',
    '*.html'
  ], {
    ignore: ['**/node_modules/**', '**/*.d.ts'],
  })

  for (const filePath of filePaths) {
    const foo = Bun.file(filePath)
    fileContents[filePath] = await foo.text()
  }

  checkUnusedDependencies(filePaths)

  console.log('👍')
}

main()