fix: ignore global prefix if --prefix is used (#5291)

When `--prefix` is used, both the local and global prefix values are set
to be identical. This is functionally broken because their directory
structures are inherently different (for instance, in posix the tree is
in `lib/node_modules` in the global prefix).

This commit makes npm exec ignore the global folders if it detects both
local and global prefix are identical.

lib/commands/exec.js

@@ -34,6 +34,7 @@ class Exec extends BaseCommand {
 
     const args = [..._args]
     const call = this.npm.config.get('call')
+    let globalPath
     const {
       flatOptions,
       localBin,
@@ -44,6 +45,12 @@ class Exec extends BaseCommand {
     const scriptShell = this.npm.config.get('script-shell') || undefined
     const packages = this.npm.config.get('package')
     const yes = this.npm.config.get('yes')
+    // --prefix sets both of these to the same thing, meaning the global prefix
+    // is invalid (i.e. no lib/node_modules).  This is not a trivial thing to
+    // untangle and fix so we work around it here.
+    if (this.npm.localPrefix !== this.npm.globalPrefix) {
+      globalPath = path.resolve(globalDir, '..')
+    }
 
     if (call && _args.length) {
       throw this.usageError()
@@ -59,7 +66,7 @@ class Exec extends BaseCommand {
       localBin,
       locationMsg,
       globalBin,
-      globalPath: path.resolve(globalDir, '..'),
+      globalPath,
       output,
       packages,
       path: localPrefix,

test/lib/commands/exec.js

@@ -28,6 +28,7 @@ t.test('registry package', async t => {
 
   const { npm } = await loadMockNpm(t, {
     config: {
+      audit: false,
       yes: true,
     },
     prefixDir: {
@@ -43,7 +44,46 @@ t.test('registry package', async t => {
   })
 
   await registry.package({
-    times: 2,
+    manifest,
+    tarballs: {
+      '1.0.0': path.join(npm.prefix, 'npm-exec-test'),
+    } })
+
+  await npm.exec('exec', ['@npmcli/npx-test'])
+  const exists = await fs.stat(path.join(npm.prefix, 'npm-exec-test-success'))
+  t.ok(exists.isFile(), 'bin ran, creating file')
+})
+
+t.test('--prefix', async t => {
+  const registry = new MockRegistry({
+    tap: t,
+    registry: 'https://registry.npmjs.org/',
+  })
+
+  const manifest = registry.manifest({ name: '@npmcli/npx-test' })
+  manifest.versions['1.0.0'].bin = { 'npx-test': 'index.js' }
+
+  const { npm } = await loadMockNpm(t, {
+    config: {
+      audit: false,
+      yes: true,
+    },
+    prefixDir: {
+      'npm-exec-test': {
+        'package.json': JSON.stringify(manifest),
+        'index.js': `#!/usr/bin/env node
+  require('fs').writeFileSync('npm-exec-test-success', '')`,
+      },
+    },
+    globals: ({ prefix }) => ({
+      'process.cwd': () => prefix,
+    }),
+  })
+
+  // This is what `--prefix` does
+  npm.globalPrefix = npm.localPrefix
+
+  await registry.package({
     manifest,
     tarballs: {
       '1.0.0': path.join(npm.prefix, 'npm-exec-test'),
@@ -65,6 +105,7 @@ t.test('workspaces', async t => {
 
   const { npm } = await loadMockNpm(t, {
     config: {
+      audit: false,
       yes: true,
       workspace: ['workspace-a'],
     },

workspaces/libnpmexec/lib/index.js

@@ -82,7 +82,7 @@ const exec = async (opts) => {
     localBin = resolve('./node_modules/.bin'),
     locationMsg = undefined,
     globalBin = '',
-    globalPath = '',
+    globalPath,
     output,
     // dereference values because we manipulate it later
     packages: [...packages] = [],
@@ -120,7 +120,7 @@ const exec = async (opts) => {
     if (localBinPath) {
       binPaths.push(localBinPath)
       return await run()
-    } else if (await fileExists(`${globalBin}/${args[0]}`)) {
+    } else if (globalPath && await fileExists(`${globalBin}/${args[0]}`)) {
       binPaths.push(globalBin)
       return await run()
     }
@@ -155,7 +155,7 @@ const exec = async (opts) => {
 
     args[0] = getBinFromManifest(commandManifest)
 
-    if (needInstall.length > 0) {
+    if (needInstall.length > 0 && globalPath) {
       // See if the package is installed globally, and run the translated bin
       const globalArb = new Arborist({ ...flatOptions, path: globalPath, global: true })
       const globalTree = await globalArb.loadActual()

workspaces/libnpmexec/test/index.js

@@ -517,6 +517,7 @@ t.test('global space pkg', async t => {
     },
   })
   const globalBin = resolve(path, 'global/node_modules/.bin')
+  const globalPath = resolve(path, 'global')
   const runPath = path
 
   const executable = resolve(path, 'global/node_modules/a')
@@ -531,6 +532,7 @@ t.test('global space pkg', async t => {
     ...baseOpts,
     args: ['a', 'resfile'],
     globalBin,
+    globalPath,
     path,
     runPath,
   })
@@ -588,12 +590,13 @@ t.test('run from registry - no local packages', async t => {
   const testdir = t.testdir({
     cache: {},
     npxCache: {},
+    global: {
+      lib: {},
+      bin: {},
+    },
     work: {},
   })
   const path = resolve(testdir, 'work')
-  const runPath = path
-  const cache = resolve(testdir, 'cache')
-  const npxCache = resolve(testdir, 'npxCache')
 
   t.throws(
     () => fs.statSync(resolve(path, 'index.js')),
@@ -604,10 +607,11 @@ t.test('run from registry - no local packages', async t => {
   await libexec({
     ...baseOpts,
     args: ['@ruyadorno/create-index'],
-    cache,
-    npxCache,
+    cache: resolve(testdir, 'cache'),
+    globalPath: resolve(testdir, 'global'),
+    npxCache: resolve(testdir, 'npxCache'),
     path,
-    runPath,
+    runPath: path,
   })
 
   t.ok(fs.statSync(resolve(path, 'index.js')).isFile(), 'ran create pkg')