Pkg Root

1#!/usr/bin/env node
2// Prints the install directory of a package — the folder holding its
3// package.json — resolved from the current working directory.
4//
5//   node pkg-root.cjs @wix/patterns
6//
7// Takes the package name as an argument and knows nothing about any particular
8// package, so it stays correct as the packages it is pointed at change.
9//
10// Three steps, because one is not enough in the repos this runs in:
11//   1. Activate Yarn PnP if a .pnp.cjs exists at or above cwd. A bare
12//      require.resolve throws in a Yarn Berry project even when the package is
13//      installed, and in a monorepo the .pnp.cjs sits at the repo root rather
14//      than beside the project being built.
15//   2. require.resolve, which handles npm, pnpm and workspace layouts.
16//   3. Failing that, walk up looking for node_modules/<pkg> directly, which
17//      covers a partially-installed tree where resolution fails but the files
18//      are on disk.
19const fs = require('fs');
20const path = require('path');
21
22const pkg = process.argv[2];
23if (!pkg) {
24  console.error('usage: pkg-root.cjs <package-name>');
25  process.exit(2);
26}
27
28function activatePnp() {
29  let dir = process.cwd();
30  for (;;) {
31    const pnp = path.join(dir, '.pnp.cjs');
32    if (fs.existsSync(pnp)) {
33      try {
34        require(pnp).setup();
35      } catch {
36        // An unusable .pnp.cjs is not fatal: the plain resolve below may still
37        // succeed against a node_modules tree.
38      }
39      return;
40    }
41    const parent = path.dirname(dir);
42    if (parent === dir) return;
43    dir = parent;
44  }
45}
46
47activatePnp();
48
49try {
50  console.log(
51    path.dirname(
52      require.resolve(`${pkg}/package.json`, { paths: [process.cwd()] }),
53    ),
54  );
55  process.exit(0);
56} catch {
57  // fall through to the directory walk
58}
59
60let dir = process.cwd();
61for (;;) {
62  const candidate = path.join(dir, 'node_modules', ...pkg.split('/'));
63  if (fs.existsSync(path.join(candidate, 'package.json'))) {
64    console.log(candidate);
65    process.exit(0);
66  }
67  const parent = path.dirname(dir);
68  if (parent === dir) {
69    console.error(`${pkg} not found from ${process.cwd()}`);
70    process.exit(1);
71  }
72  dir = parent;
73}