feat: add proxyVarSubDir option to path extenders

Allow specifying a subdirectory of the proxy variable to add to PATH,
e.g. PNPM_HOME/bin instead of PNPM_HOME. Supports posix (bash, fish,
nushell) and windows shells.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: zkochan

os/env/path-extender-posix/path-extender-posix.spec.ts

@@ -83,6 +83,36 @@ case ":$PATH:" in
   *) export PATH="${pnpmHomeDir}:$PATH" ;;
 esac
 # pnpm end
+`)
+  })
+  it('should append to shell script with proxyVarSubDir', async () => {
+    fs.writeFileSync(configFile, '', 'utf8')
+    const report = await addDirToPosixEnvPath(pnpmHomeDir, {
+      proxyVarName: 'PNPM_HOME',
+      proxyVarSubDir: 'bin',
+      configSectionName: 'pnpm',
+    })
+    expect(report).toStrictEqual({
+      configFile: {
+        path: configFile,
+        changeType: 'appended',
+      },
+      oldSettings: '',
+      newSettings: `export PNPM_HOME="${pnpmHomeDir}"
+case ":$PATH:" in
+  *":$PNPM_HOME/bin:"*) ;;
+  *) export PATH="$PNPM_HOME/bin:$PATH" ;;
+esac`,
+    })
+    const configContent = fs.readFileSync(configFile, 'utf8')
+    expect(configContent).toEqual(`
+# pnpm
+export PNPM_HOME="${pnpmHomeDir}"
+case ":$PATH:" in
+  *":$PNPM_HOME/bin:"*) ;;
+  *) export PATH="$PNPM_HOME/bin:$PATH" ;;
+esac
+# pnpm end
 `)
   })
   it('should put the new directory to the end of the PATH', async () => {

os/env/path-extender-posix/path-extender-posix.ts

@@ -17,6 +17,7 @@ export type AddingPosition = 'start' | 'end'
 
 export interface AddDirToPosixEnvPathOpts {
   proxyVarName?: string
+  proxyVarSubDir?: string
   overwrite?: boolean
   position?: AddingPosition
   configSectionName: string
@@ -93,10 +94,11 @@ async function setupShell (
   let newSettings!: string
   const _createPathValue = createPathValue.bind(null, opts.position ?? 'start')
   if (opts.proxyVarName) {
+    const pathRef = opts.proxyVarSubDir ? `$${opts.proxyVarName}/${opts.proxyVarSubDir}` : `$${opts.proxyVarName}`
     newSettings = `export ${opts.proxyVarName}="${dir}"
 case ":$PATH:" in
-  *":$${opts.proxyVarName}:"*) ;;
-  *) export PATH="${_createPathValue(`$${opts.proxyVarName}`)}" ;;
+  *":${pathRef}:"*) ;;
+  *) export PATH="${_createPathValue(pathRef)}" ;;
 esac`
   } else {
     newSettings = `case ":$PATH:" in
@@ -141,9 +143,10 @@ async function setupFishShell (dir: string, opts: AddDirToPosixEnvPathOpts): Pro
   let newSettings!: string
   const _createPathValue = createFishPathValue.bind(null, opts.position ?? 'start')
   if (opts.proxyVarName) {
+    const pathRef = opts.proxyVarSubDir ? `$${opts.proxyVarName}/${opts.proxyVarSubDir}` : `$${opts.proxyVarName}`
     newSettings = `set -gx ${opts.proxyVarName} "${dir}"
-if not string match -q -- $${opts.proxyVarName} $PATH
-  set -gx PATH ${_createPathValue(`$${opts.proxyVarName}`)}
+if not string match -q -- ${pathRef} $PATH
+  set -gx PATH ${_createPathValue(pathRef)}
 end`
   } else {
     newSettings = `if not string match -q -- "${dir}" $PATH
@@ -167,8 +170,11 @@ async function setupNuShell (dir: string, opts: AddDirToPosixEnvPathOpts): Promi
   let newSettings!: string
   const addingCommand = (opts.position ?? "start") === "start" ? "prepend" : "append"
   if (opts.proxyVarName) {
+    const pathRef = opts.proxyVarSubDir
+      ? `($env.${opts.proxyVarName} | path join "${opts.proxyVarSubDir}")`
+      : `$env.${opts.proxyVarName}`
     newSettings = `$env.${opts.proxyVarName} = "${dir}"
-$env.PATH = ($env.PATH | split row (char esep) | ${addingCommand} $env.${opts.proxyVarName} )`
+$env.PATH = ($env.PATH | split row (char esep) | ${addingCommand} ${pathRef} )`
   } else {
     newSettings = `$env.PATH = ($env.PATH | split row (char esep) | ${addingCommand} ${dir} )`
   }

os/env/path-extender-windows/path-extender-windows.ts

@@ -23,6 +23,7 @@ export type AddingPosition = 'start' | 'end'
 
 export interface AddDirToWindowsEnvPathOpts {
   proxyVarName?: string
+  proxyVarSubDir?: string
   overwriteProxyVar?: boolean
   position?: AddingPosition
 }
@@ -69,7 +70,10 @@ async function _addDirToWindowsEnvPath (dir: string, opts: AddDirToWindowsEnvPat
       expandableString: false,
       overwrite: opts.overwriteProxyVar ?? false
     }))
-    changes.push(await addToPath(registryOutput, `%${opts.proxyVarName}%`, opts.position))
+    const pathEntry = opts.proxyVarSubDir
+      ? `%${opts.proxyVarName}%${path.sep}${opts.proxyVarSubDir}`
+      : `%${opts.proxyVarName}%`
+    changes.push(await addToPath(registryOutput, pathEntry, opts.position))
   } else {
     changes.push(await addToPath(registryOutput, addedDir, opts.position))
   }

os/env/path-extender/path-extender.ts

@@ -18,6 +18,7 @@ export async function addDirToEnvPath(dir: string, opts: AddDirToEnvPathOpts): P
     return renderWindowsReport(await addDirToWindowsEnvPath(dir, {
         position: opts.position,
         proxyVarName: opts.proxyVarName,
+        proxyVarSubDir: opts.proxyVarSubDir,
         overwriteProxyVar: opts.overwrite,
       })
     )