Fix Windows path calculation in pyenvUtils for environment grouping

On Windows, pyenv-win is at ~/.pyenv/pyenv-win/bin/pyenv.bat, so we
need to go up 3 directory levels (not 2) to reach the pyenv root
directory (~/.pyenv). This fixes environment grouping (PYENV_VERSIONS
vs PYENV_ENVIRONMENTS) which was broken because versionsPath and
envsPaths were calculated from the wrong parent directory.

Co-authored-by: karthiknadig <3840081+karthiknadig@users.noreply.github.com>

Author: Copilot

package-lock.json

@@ -23,6 +23,18 @@ import {
 } from '../common/nativePythonFinder';
 import { shortVersion, sortEnvironments } from '../common/utils';
 
+/**
+ * Returns the pyenv root directory from the pyenv executable path.
+ * On Windows, pyenv-win is at `~/.pyenv/pyenv-win/bin/pyenv.bat` (3 levels up).
+ * On POSIX, pyenv is at `~/.pyenv/bin/pyenv` (2 levels up).
+ */
+export function getPyenvDir(pyenv: string): string {
+    if (isWindows()) {
+        return path.dirname(path.dirname(path.dirname(pyenv)));
+    }
+    return path.dirname(path.dirname(pyenv));
+}
+
 async function findPyenv(): Promise<string | undefined> {
     try {
         return await which('pyenv');
@@ -174,8 +186,9 @@ function nativeToPythonEnv(
         return undefined;
     }
 
-    const versionsPath = normalizePath(path.join(path.dirname(path.dirname(pyenv)), 'versions'));
-    const envsPaths = normalizePath(path.join(path.dirname(versionsPath), 'envs'));
+    const pyenvDir = getPyenvDir(pyenv);
+    const versionsPath = normalizePath(path.join(pyenvDir, 'versions'));
+    const envsPaths = normalizePath(path.join(pyenvDir, 'envs'));
     let group = undefined;
     const normPrefix = normalizePath(info.prefix);
     if (normPrefix.startsWith(versionsPath)) {

src/managers/pyenv/pyenvUtils.ts

@@ -0,0 +1,33 @@
+import assert from 'node:assert';
+import * as path from 'path';
+import * as sinon from 'sinon';
+import * as platformUtils from '../../../common/utils/platformUtils';
+import { getPyenvDir } from '../../../managers/pyenv/pyenvUtils';
+
+suite('pyenvUtils - getPyenvDir', () => {
+    let isWindowsStub: sinon.SinonStub;
+
+    setup(() => {
+        isWindowsStub = sinon.stub(platformUtils, 'isWindows');
+    });
+
+    teardown(() => {
+        sinon.restore();
+    });
+
+    test('should go up 2 levels on POSIX (bin/pyenv -> pyenv root)', () => {
+        isWindowsStub.returns(false);
+        // e.g. /home/user/.pyenv/bin/pyenv
+        const pyenvBin = path.join('home', 'user', '.pyenv', 'bin', 'pyenv');
+        const result = getPyenvDir(pyenvBin);
+        assert.strictEqual(result, path.join('home', 'user', '.pyenv'));
+    });
+
+    test('should go up 3 levels on Windows (pyenv-win/bin/pyenv.bat -> pyenv root)', () => {
+        isWindowsStub.returns(true);
+        // e.g. C:\Users\user\.pyenv\pyenv-win\bin\pyenv.bat
+        const pyenvBin = path.join('C:', 'Users', 'user', '.pyenv', 'pyenv-win', 'bin', 'pyenv.bat');
+        const result = getPyenvDir(pyenvBin);
+        assert.strictEqual(result, path.join('C:', 'Users', 'user', '.pyenv'));
+    });
+});