feat: add walk up dir lookup to satisfy local bins

Currently @npmcli/run-script already supports this walk up lookup logic
that allows any nested folder to use a bin that is located inside a
node_modules/.bin folder higher in the directory tree.

This commit adds the same logic from:
https://github.com/npm/run-script/blob/47a4d539fb07220e7215cc0e482683b76407ef9b/lib/set-path.js#L24-L28
to libnpmexec so that users may use a binary from a dependency of a
nested workspace in the context of that workspaces' folder.

Fixes: npm/cli#2826

README.md

@@ -31,7 +31,7 @@ await libexec({
   - `call`: An alternative command to run when using `packages` option **String**, defaults to empty string.
   - `cache`: The path location to where the npm cache folder is placed **String**
   - `color`: Output should use color? **Boolean**, defaults to `false`
-  - `localBin`: Location to the `node_modules/.bin` folder of the local project **String**, defaults to empty string.
+  - `localBin`: Location to the `node_modules/.bin` folder of the local project **String** to start scanning for bin files, defaults to `./node_modules/.bin`. **libexec** will walk up the directory structure looking for `node_modules/.bin` folders in parent folders that might satisfy the current `arg` and will use that bin if found.
   - `locationMsg`: Overrides "at location" message when entering interactive mode **String**
   - `log`: Sets an optional logger **Object**, defaults to `proc-log` module usage.
   - `globalBin`: Location to the global space bin folder, same as: `$(npm bin -g)` **String**, defaults to empty string.

lib/file-exists.js

@@ -0,0 +1,26 @@
+const { dirname, resolve } = require('path')
+const { promisify } = require('util')
+const stat = promisify(require('fs').stat)
+
+const fileExists = (file) => stat(file)
+  .then((stat) => stat.isFile())
+  .catch(() => false)
+
+const localFileExists = async (dir, binName) => {
+  const binDir = resolve(dir, 'node_modules', '.bin')
+
+  // return localBin if existing file is found
+  if (await fileExists(resolve(binDir, binName)))
+    return binDir
+
+  // no more dirs left to walk up, file just does not exist
+  if (dir === dirname(dir))
+    return false
+
+  return localFileExists(dirname(dir), binName)
+}
+
+module.exports = {
+  fileExists,
+  localFileExists,
+}

lib/index.js

@@ -1,7 +1,6 @@
-const { delimiter, resolve } = require('path')
+const { delimiter, dirname, resolve } = require('path')
 const { promisify } = require('util')
 const read = promisify(require('read'))
-const stat = promisify(require('fs').stat)
 
 const Arborist = require('@npmcli/arborist')
 const ciDetect = require('@npmcli/ci-detect')
@@ -12,15 +11,12 @@ const pacote = require('pacote')
 const readPackageJson = require('read-package-json-fast')
 
 const cacheInstallDir = require('./cache-install-dir.js')
+const { fileExists, localFileExists } = require('./file-exists.js')
 const getBinFromManifest = require('./get-bin-from-manifest.js')
 const manifestMissing = require('./manifest-missing.js')
 const noTTY = require('./no-tty.js')
 const runScript = require('./run-script.js')
 
-const fileExists = (file) => stat(file)
-  .then((stat) => stat.isFile())
-  .catch(() => false)
-
 /* istanbul ignore next */
 const PATH = (
   process.env.PATH || process.env.Path || process.env.path
@@ -31,7 +27,7 @@ const exec = async (opts) => {
     args = [],
     call = '',
     color = false,
-    localBin = '',
+    localBin = resolve('./node_modules/.bin'),
     locationMsg = undefined,
     globalBin = '',
     output,
@@ -72,8 +68,10 @@ const exec = async (opts) => {
   // the behavior of treating the single argument as a package name
   if (needPackageCommandSwap) {
     let binExists = false
-    if (await fileExists(`${localBin}/${args[0]}`)) {
-      pathArr.unshift(localBin)
+    const dir = dirname(dirname(localBin))
+    const localBinPath = await localFileExists(dir, args[0])
+    if (localBinPath) {
+      pathArr.unshift(localBinPath)
       binExists = true
     } else if (await fileExists(`${globalBin}/${args[0]}`)) {
       pathArr.unshift(globalBin)

test/index.js

@@ -515,3 +515,77 @@ t.test('sane defaults', async t => {
   t.ok(fs.statSync(resolve(workdir, 'index.js')).isFile(),
     'ran create-index pkg')
 })
+
+t.only('workspaces', async t => {
+  const pkg = {
+    name: '@ruyadorno/create-index',
+    version: '2.0.0',
+    bin: {
+      'create-index': './index.js',
+    },
+  }
+  const path = t.testdir({
+    cache: {},
+    node_modules: {
+      '.bin': {},
+      '@ruyadorno': {
+        'create-index': {
+          'package.json': JSON.stringify(pkg),
+          'index.js': `#!/usr/bin/env node
+  require('fs').writeFileSync('resfile', 'LOCAL PKG')`,
+        },
+      },
+      a: t.fixture('symlink', '../a'),
+    },
+    'package.json': JSON.stringify({
+      name: 'project',
+      workspaces: ['a'],
+    }),
+    a: {
+      'package.json': JSON.stringify({
+        name: 'a',
+        version: '1.0.0',
+        dependencies: {
+          '@ruyadorno/create-index': '^2.0.0',
+        },
+      }),
+    }
+  })
+  const runPath = path
+  const cache = resolve(path, 'cache')
+
+  const executable =
+    resolve(path, 'node_modules/@ruyadorno/create-index/index.js')
+  fs.chmodSync(executable, 0o775)
+
+  await binLinks({
+    path: resolve(path, 'node_modules/@ruyadorno/create-index'),
+    pkg,
+  })
+
+  // runs at the project level
+  await libexec({
+    ...baseOpts,
+    args: ['create-index'],
+    localBin: resolve(path, 'node_modules/.bin'),
+    cache,
+    path,
+    runPath,
+  })
+
+  const res = fs.readFileSync(resolve(path, 'resfile')).toString()
+  t.equal(res, 'LOCAL PKG', 'should run existing bin from project level')
+
+  // runs at the child workspace level
+  await libexec({
+    ...baseOpts,
+    args: ['create-index'],
+    cache,
+    localBin: resolve(path, 'a/node_modules/.bin'),
+    path: resolve(path, 'a'),
+    runPath: resolve(path, 'a'),
+  })
+
+  const wRes = fs.readFileSync(resolve(path, 'a/resfile')).toString()
+  t.equal(wRes, 'LOCAL PKG', 'should run existing bin from workspace level')
+})