From 355fefb10979bd3a6bacd20fb5d0b8efd7011ece Mon Sep 17 00:00:00 2001
From: amishabenramani <amishabenramani@gmail.com>
Date: Sat, 26 Sep 2026 00:05:09 +0200
Subject: [PATCH] fix: repair PNPM_HOME registry type

---
 .../path-extender-windows.spec.ts             | 52 +++++++++++++++++--
 .../path-extender-windows.ts                  | 22 +++++---
 2 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/os/env/path-extender-windows/path-extender-windows.spec.ts b/os/env/path-extender-windows/path-extender-windows.spec.ts
index 0d9763f..af30d6a 100644
--- a/os/env/path-extender-windows/path-extender-windows.spec.ts
+++ b/os/env/path-extender-windows/path-extender-windows.spec.ts
@@ -325,7 +325,7 @@ HKEY_CURRENT_USER\\Environment
   expect(report).toStrictEqual([
     {
       variable: 'PNPM_HOME',
-      action: 'skipped',
+      action: 'updated',
       oldValue: pnpmHomeDirNormalized,
       newValue: pnpmHomeDirNormalized,
     },
@@ -337,9 +337,53 @@ HKEY_CURRENT_USER\\Environment
     },
   ])
   expect(execa).toHaveBeenNthCalledWith(3, 'reg', ['query', regKey], { windowsHide: false })
-  expect(execa).toHaveBeenNthCalledWith(4, 'reg', ['add', regKey, '/v', 'Path', '/t', 'REG_EXPAND_SZ', '/d', `%PNPM_HOME%;${currentPathInRegistry}`, '/f'], { windowsHide: false })
-  expect(execa).toHaveBeenNthCalledWith(5, 'setx', ['REFRESH_ENV_VARS', '1'], { windowsHide: false })
-  expect(execa).toHaveBeenNthCalledWith(6, 'reg', ['delete' ,regKey, '/v', 'REFRESH_ENV_VARS', '/f'], { windowsHide: false })
+  expect(execa).toHaveBeenNthCalledWith(4, 'reg', ['add', regKey, '/v', 'PNPM_HOME', '/t', 'REG_SZ', '/d', pnpmHomeDirNormalized, '/f'], { windowsHide: false })
+  expect(execa).toHaveBeenNthCalledWith(5, 'reg', ['add', regKey, '/v', 'Path', '/t', 'REG_EXPAND_SZ', '/d', `%PNPM_HOME%;${currentPathInRegistry}`, '/f'], { windowsHide: false })
+  expect(execa).toHaveBeenNthCalledWith(6, 'setx', ['REFRESH_ENV_VARS', '1'], { windowsHide: false })
+  expect(execa).toHaveBeenNthCalledWith(7, 'reg', ['delete' ,regKey, '/v', 'REFRESH_ENV_VARS', '/f'], { windowsHide: false })
+})
+
+test('PNPM_HOME with the correct registry type is left unchanged', async () => {
+  const pnpmHomeDir = tempDir(false)
+  const pnpmHomeDirNormalized = path.normalize(pnpmHomeDir)
+  const currentPathInRegistry = '%PNPM_HOME%;C:\Windows'
+  execa['mockResolvedValueOnce']({
+    failed: false,
+    stdout: 'Active code page: 437',
+  }).mockResolvedValueOnce({
+    failed: false,
+    stdout: '',
+  }).mockResolvedValueOnce({
+    failed: false,
+    stdout: '\nHKEY_CURRENT_USER\\Environment\n    PNPM_HOME    REG_SZ    ' + pnpmHomeDirNormalized + '\n    Path    REG_EXPAND_SZ    ' + currentPathInRegistry + '\n',
+  }).mockResolvedValueOnce({
+    failed: false,
+    stdout: '',
+  }).mockResolvedValueOnce({
+    failed: false,
+    stdout: '',
+  }).mockResolvedValueOnce({
+    failed: false,
+    stdout: '',
+  })
+
+  const report = await addDirToWindowsEnvPath(pnpmHomeDir, { proxyVarName: 'PNPM_HOME' })
+
+  expect(report).toStrictEqual([
+    {
+      variable: 'PNPM_HOME',
+      action: 'skipped',
+      oldValue: pnpmHomeDirNormalized,
+      newValue: pnpmHomeDirNormalized,
+    },
+    {
+      variable: 'Path',
+      action: 'skipped',
+      oldValue: currentPathInRegistry,
+      newValue: currentPathInRegistry,
+    },
+  ])
+  expect(execa).not.toHaveBeenCalledWith('reg', expect.arrayContaining(['add']), { windowsHide: false })
 })
 
 test('setup throws an error if PNPM_HOME is already set to a different directory', async () => {
diff --git a/os/env/path-extender-windows/path-extender-windows.ts b/os/env/path-extender-windows/path-extender-windows.ts
index af761bd..c222378 100644
--- a/os/env/path-extender-windows/path-extender-windows.ts
+++ b/os/env/path-extender-windows/path-extender-windows.ts
@@ -90,16 +90,19 @@ async function updateEnvVariable (
     overwrite: boolean
   }
 ): Promise<EnvVariableChange> {
-  const currentValue = await getEnvValueFromRegistry(registryOutput, name)
+  const current = await getEnvValueFromRegistryWithType(registryOutput, name)
+  const currentValue = current?.data
   if (currentValue && !opts.overwrite) {
     if (currentValue !== value) {
       throw new BadEnvVariableError({ envName: name, currentValue, wantedValue: value })
     }
-    return { variable: name, action: 'skipped', oldValue: currentValue, newValue: value }
-  } else {
-    await setEnvVarInRegistry(name, value, { expandableString: opts.expandableString })
-    return { variable: name, action: 'updated', oldValue: currentValue as string, newValue: value }
+    const wantedType = opts.expandableString ? 'REG_EXPAND_SZ' : 'REG_SZ'
+    if (current.type === wantedType) {
+      return { variable: name, action: 'skipped', oldValue: currentValue, newValue: value }
+    }
   }
+  await setEnvVarInRegistry(name, value, { expandableString: opts.expandableString })
+  return { variable: name, action: 'updated', oldValue: currentValue as string, newValue: value }
 }
 
 async function addToPath (registryOutput: string, addedDir: string, position: AddingPosition = 'start'): Promise<EnvVariableChange> {
@@ -136,9 +139,16 @@ async function getRegistryOutput (): Promise<string> {
 }
 
 async function getEnvValueFromRegistry (registryOutput: string, envVarName: string): Promise<string | undefined> {
+  return (await getEnvValueFromRegistryWithType(registryOutput, envVarName))?.data
+}
+
+async function getEnvValueFromRegistryWithType (
+  registryOutput: string,
+  envVarName: string
+): Promise<IEnvironmentValueMatch['groups'] | undefined> {
   const regexp = new RegExp(`^ {4}(?<name>${envVarName}) {4}(?<type>\\w+) {4}(?<data>.*)$`, 'gim')
   const match = Array.from(matchAll(registryOutput, regexp))[0] as IEnvironmentValueMatch
-  return match?.groups.data
+  return match?.groups
 }
 
 async function setEnvVarInRegistry (