pkgs/build-support/node/import-npm-lock/hooks/canonicalize-symlinks.js

   1 #!/usr/bin/env node
   2 const fs = require("fs");
   3 const path = require("path");
   4
   5 // When installing files rewritten to the Nix store with npm
   6 // npm writes the symlinks relative to the build directory.
   7 //
   8 // This makes relocating node_modules tricky when refering to the store.
   9 // This script walks node_modules and canonicalizes symlinks.
  10
  11 async function canonicalize(storePrefix, root) {
  12   console.log(storePrefix, root)
  13   const entries = await fs.promises.readdir(root);
  14   const paths = entries.map((entry) => path.join(root, entry));
  15
  16   const stats = await Promise.all(
  17     paths.map(async (path) => {
  18       return {
  19         path: path,
  20         stat: await fs.promises.lstat(path),
  21       };
  22     })
  23   );
  24
  25   const symlinks = stats.filter((stat) => stat.stat.isSymbolicLink());
  26   const dirs = stats.filter((stat) => stat.stat.isDirectory());
  27
  28   // Canonicalize symlinks to their real path
  29   await Promise.all(
  30     symlinks.map(async (stat) => {
  31       const target = await fs.promises.realpath(stat.path);
  32       if (target.startsWith(storePrefix)) {
  33         await fs.promises.unlink(stat.path);
  34         await fs.promises.symlink(target, stat.path);
  35       }
  36     })
  37   );
  38
  39   // Recurse into directories
  40   await Promise.all(dirs.map((dir) => canonicalize(storePrefix, dir.path)));
  41 }
  42
  43 async function main() {
  44   const args = process.argv.slice(2);
  45   const storePrefix = args[0];
  46
  47   if (fs.existsSync("node_modules")) {
  48     await canonicalize(storePrefix, "node_modules");
  49   }
  50 }
  51
  52 main();