analyze-packages.js

const fs = require("fs")
const path = require("path")
const parser = require("@babel/parser")
const traverse = require("@babel/traverse").default
const glob = require("glob")

// Function to get all JS/TS files in the project
function getProjectFiles(projectRoot) {
  return glob.sync("**/*.{js,jsx,ts,tsx}", {
    cwd: projectRoot,
    ignore: ["node_modules/**", ".next/**", "out/**", "build/**", "dist/**"],
  })
}

// Function to parse package.json and get dependencies
function getDependencies(projectRoot) {
  const packageJson = JSON.parse(fs.readFileSync(path.join(projectRoot, "package.json"), "utf8"))
  return {
    ...packageJson.dependencies,
    ...packageJson.devDependencies,
  }
}

// Function to get all exports from a package
function getPackageExports(packageName) {
  try {
    const packagePath = require.resolve(packageName)
    const pkg = require(packagePath)
    return Object.keys(pkg)
  } catch (error) {
    console.warn(`Could not analyze exports for package: ${packageName}`)
    return []
  }
}

// Function to analyze imports in a file
function analyzeFileImports(filePath, projectRoot) {
  const content = fs.readFileSync(path.join(projectRoot, filePath), "utf8")
  const imports = new Set()

  try {
    const ast = parser.parse(content, {
      sourceType: "module",
      plugins: ["jsx", "typescript", "decorators-legacy"],
    })

    traverse(ast, {
      ImportDeclaration(path) {
        const source = path.node.source.value
        if (!source.startsWith(".") && !source.startsWith("/")) {
          const packageName = source.split("/")[0]
          path.node.specifiers.forEach((specifier) => {
            if (specifier.type === "ImportSpecifier") {
              imports.add(`${packageName}:${specifier.imported.name}`)
            }
          })
        }
      },
    })
  } catch (error) {
    console.warn(`Error parsing file ${filePath}:`, error.message)
  }

  return imports
}

// Main function to analyze the project
async function analyzeProject(projectRoot) {
  const files = getProjectFiles(projectRoot)
  const dependencies = getDependencies(projectRoot)
  const packageImports = new Map()
  const unusedExports = new Map()

  // Initialize package exports
  for (const pkg of Object.keys(dependencies)) {
    const exports = getPackageExports(pkg)
    if (exports.length > 0) {
      unusedExports.set(pkg, new Set(exports))
    }
  }

  // Analyze each file
  for (const file of files) {
    const imports = analyzeFileImports(file, projectRoot)

    for (const imp of imports) {
      const [pkg, exportName] = imp.split(":")
      if (unusedExports.has(pkg)) {
        unusedExports.get(pkg).delete(exportName)
      }

      if (!packageImports.has(pkg)) {
        packageImports.set(pkg, new Set())
      }
      packageImports.get(pkg).add(exportName)
    }
  }

  // Find packages with unused exports
  const packagesWithUnusedExports = []
  for (const [pkg, unused] of unusedExports) {
    if (unused.size > 0) {
      packagesWithUnusedExports.push({
        package: pkg,
        unusedCount: unused.size,
        totalExports: getPackageExports(pkg).length,
        unusedExports: Array.from(unused),
      })
    }
  }

  return packagesWithUnusedExports
}

// Run the analysis
const projectRoot = process.cwd()
analyzeProject(projectRoot)
  .then((results) => {
    console.log("\nPackages with unused exports:")
    console.log("============================")

    const optimizePackageImports = results
      .filter((pkg) => pkg.unusedCount > 5) // Threshold for significant unused exports
      .map((pkg) => pkg.package)

    results.forEach((pkg) => {
      console.log(`\n${pkg.package}:`)
      console.log(`- ${pkg.unusedCount} unused exports out of ${pkg.totalExports} total exports`)
      console.log(
        "- Unused exports:",
        pkg.unusedExports.slice(0, 5).join(", ") +
          (pkg.unusedExports.length > 5 ? ` and ${pkg.unusedExports.length - 5} more...` : ""),
      )
    })

    console.log("\nRecommended optimizePackageImports configuration:")
    console.log("=============================================")
    console.log("Add this to your next.config.js:")
    console.log("optimizePackageImports: [")
    optimizePackageImports.forEach((pkg) => console.log(`  '${pkg}',`))
    console.log("]")
  })
  .catch((error) => {
    console.error("Error analyzing project:", error)
  })