fix: root -g should not fail

`pnpm root -g` should not fail if the pnpm process has no access
to the global bin directory.

close #2700
PR #2704

.changeset/eight-penguins-hunt.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/cli-utils": minor
+"@pnpm/config": minor
+---
+
+A new option added that allows to resolve the global bin directory from directories to which there is no write access.

.changeset/orange-clocks-pretend.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/global-bin-dir": minor
+---
+
+Add a new optional argument. When the argument is `false`, a global bin directory is returned even if the process has no write access to it.

packages/cli-utils/src/getConfig.ts

@@ -5,12 +5,14 @@ export default async function (
   cliOptions: CliOptions,
   opts: {
     excludeReporter: boolean,
+    globalDirShouldAllowWrite?: boolean,
     rcOptionsTypes: Record<string, unknown>,
     workspaceDir: string | undefined,
   }
 ) {
   const { config, warnings } = await getConfig({
     cliOptions,
+    globalDirShouldAllowWrite: opts.globalDirShouldAllowWrite,
     packageManager,
     rcOptionsTypes: opts.rcOptionsTypes,
     workspaceDir: opts.workspaceDir,

packages/config/src/index.ts

@@ -91,6 +91,7 @@ export type CliOptions = Record<string, unknown> & { dir?: string }
 
 export default async (
   opts: {
+    globalDirShouldAllowWrite?: boolean,
     cliOptions: CliOptions,
     packageManager: {
       name: string,
@@ -229,7 +230,7 @@ export default async (
         process.platform === 'win32'
           ? cliOptions.dir : path.resolve(cliOptions.dir, 'bin')
       )
-      : globalBinDir([pnpmConfig.npmGlobalBinDir])
+      : globalBinDir([pnpmConfig.npmGlobalBinDir], { shouldAllowWrite: opts.globalDirShouldAllowWrite === true })
     pnpmConfig.allowNew = true
     pnpmConfig.ignoreCurrentPrefs = true
     pnpmConfig.saveProd = true

packages/global-bin-dir/src/index.ts

@@ -4,7 +4,10 @@ import fs = require('fs')
 import path = require('path')
 import PATH = require('path-name')
 
-export default function (knownCandidates: string[] = []) {
+export default function (
+  knownCandidates: string[] = [],
+  { shouldAllowWrite = true }: { shouldAllowWrite?: boolean } = {}
+) {
   if (!process.env[PATH]) {
     throw new PnpmError('NO_PATH_ENV',
       `Couldn't find a global directory for executables because the "${PATH}" environment variable is not set.`)
@@ -14,13 +17,17 @@ export default function (knownCandidates: string[] = []) {
   return pickBestGlobalBinDir(dirs, [
     ...knownCandidates,
     nodeBinDir,
-  ])
+  ], shouldAllowWrite)
 }
 
 const areDirsEqual = (dir1: string, dir2: string) =>
   path.relative(dir1, dir2) === ''
 
-function pickBestGlobalBinDir (dirs: string[], knownCandidates: string[]) {
+function pickBestGlobalBinDir (
+  dirs: string[],
+  knownCandidates: string[],
+  shouldAllowWrite: boolean
+) {
   const noWriteAccessDirs = [] as string[]
   for (const dir of dirs) {
     const lowCaseDir = dir.toLowerCase()
@@ -41,10 +48,13 @@ function pickBestGlobalBinDir (dirs: string[], knownCandidates: string[]) {
       hint: `There should be a node, nodejs, npm, or pnpm directory in the "${PATH}" environment variable`,
     })
   }
-  throw new PnpmError('GLOBAL_BIN_DIR_PERMISSION', 'No write access to the found global executable directories', {
-    hint: `The found directories:
-${noWriteAccessDirs.join('\n')}`,
-  })
+  if (shouldAllowWrite) {
+    throw new PnpmError('GLOBAL_BIN_DIR_PERMISSION', 'No write access to the found global executable directories', {
+      hint: `The found directories:
+  ${noWriteAccessDirs.join('\n')}`,
+    })
+  }
+  return noWriteAccessDirs[0]
 }
 
 const NODE_RELATED_COMMANDS = new Set(['pnpm', 'npm', 'node'])

packages/global-bin-dir/test/index.ts

@@ -100,6 +100,12 @@ test('when the process has no write access to any of the suitable directories, t
   t.end()
 })
 
+test('when the process has no write access to any of the suitable directories, but opts.shouldAllowWrite is false, return the first match', (t) => {
+  canWriteToDir = (dir) => dir === otherDir
+  t.equal(globalBinDir([], { shouldAllowWrite: false }), nodeGlobalBin)
+  t.end()
+})
+
 test('throw an exception if non of the directories in the PATH are suitable', (t) => {
   const pathEnv = process.env[FAKE_PATH]
   process.env[FAKE_PATH] = [otherDir].join(path.delimiter)

packages/pnpm/src/main.ts

@@ -78,8 +78,12 @@ export default async function run (inputArgv: string[]) {
     argv: { remain: string[], cooked: string[], original: string[] },
   }
   try {
+    // When we just want to print the location of the global bin directory,
+    // we don't need the write permission to it. Related issue: #2700
+    const globalDirShouldAllowWrite = cmd === 'root'
     config = await getConfig(cliOptions, {
       excludeReporter: false,
+      globalDirShouldAllowWrite,
       rcOptionsTypes: getRCOptionsTypes(cmd),
       workspaceDir,
     }) as typeof config