add js user specified locator unit test

added a comment to the native python finder to add a test in the future

extensions/positron-python/src/test/pythonEnvironments/base/locators/lowLevel/userSpecifiedEnvLocator.unit.test.ts

@@ -0,0 +1,160 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (C) 2025 Posit Software, PBC. All rights reserved.
+ *  Licensed under the Elastic License 2.0. See LICENSE.txt for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/* eslint-disable consistent-return */
+
+import * as path from 'path';
+import * as sinon from 'sinon';
+import * as TypeMoq from 'typemoq';
+import { WorkspaceConfiguration } from 'vscode';
+import * as fs from '../../../../../client/common/platform/fs-paths';
+import * as workspaceApis from '../../../../../client/common/vscodeApis/workspaceApis';
+import { PythonEnvKind } from '../../../../../client/pythonEnvironments/base/info';
+import { getEnvs } from '../../../../../client/pythonEnvironments/base/locatorUtils';
+import { UserSpecifiedEnvironmentLocator } from '../../../../../client/pythonEnvironments/base/locators/lowLevel/userSpecifiedEnvLocator';
+import { createBasicEnv } from '../../common';
+import { TEST_LAYOUT_ROOT } from '../../../common/commonTestConstants';
+import { assertBasicEnvsEqual } from '../envTestUtils';
+import { createTypeMoq } from '../../../../mocks/helper';
+import { INTERPRETERS_INCLUDE_SETTING_KEY } from '../../../../../client/common/constants';
+import { getOSType, OSType } from '../../../../common';
+
+/**
+ * Helper class to create fake executables for the user specified environments locator.
+ */
+class UserSpecifiedEnvs {
+    /**
+     * The list of executables that have been created.
+     */
+    private _executables: string[] = [];
+
+    /**
+     * Constructor.
+     * @param root The root directory where the executables will be created
+     */
+    constructor(private readonly root: string) {}
+
+    /**
+     * Creates a fake executable at the specified path. The path can be relative to the root directory.
+     * @param interpreterPath The path to the interpreter to create, including the executable name.
+     * @returns The full path to the created executable.
+     */
+    public async create(interpreterPath: string): Promise<string> {
+        const filePath = path.isAbsolute(interpreterPath) ? interpreterPath : path.join(this.root, interpreterPath);
+
+        try {
+            await fs.createFile(filePath);
+        } catch (err) {
+            throw new Error(`Failed to create executable ${interpreterPath} at ${filePath}, Error: ${err}`);
+        }
+
+        // Add the executable to the list of created executables so that they can be cleaned up later.
+        this._executables.push(filePath);
+        return filePath;
+    }
+
+    get executables(): string[] {
+        return this._executables;
+    }
+}
+
+const customWindowsEnvs = [
+    'my\\custom\\dir\\for\\pythons\\python-main\\python.exe',
+    'another\\dir\\for\\pythons\\python.exe',
+];
+
+const customPosixEnvs = ['my/custom/dir/for/pythons/python-main/bin/python', 'another/dir/for/pythons/python'];
+
+suite('UserSpecifiedEnvironment Locator', () => {
+    const userSpecifiedEnvsRoot = path.join(TEST_LAYOUT_ROOT, 'userSpecifiedEnvs', 'envs');
+    const userSpecifiedEnvs = new UserSpecifiedEnvs(userSpecifiedEnvsRoot);
+    let locator: UserSpecifiedEnvironmentLocator;
+    let pythonConfig: TypeMoq.IMock<WorkspaceConfiguration>;
+    let getConfigurationStub: sinon.SinonStub;
+
+    // Setup before all tests
+    suiteSetup(async () => {
+        // Set up the python configuration settings mocks/stubs
+        pythonConfig = createTypeMoq<WorkspaceConfiguration>();
+        getConfigurationStub = sinon.stub(workspaceApis, 'getConfiguration');
+        getConfigurationStub.callsFake((section?: string) => {
+            if (section === 'python') {
+                return pythonConfig.object;
+            }
+            return undefined;
+        });
+
+        // Create the fake custom environments for the appropriate OS
+        if (getOSType() === OSType.Windows) {
+            await Promise.all(customWindowsEnvs.map((env) => userSpecifiedEnvs.create(env)));
+        } else {
+            await Promise.all(customPosixEnvs.map((env) => userSpecifiedEnvs.create(env)));
+        }
+    });
+
+    // Setup before each test
+    setup(async () => {
+        locator = new UserSpecifiedEnvironmentLocator();
+    });
+
+    // Teardown after each test
+    teardown(async () => {
+        await locator.dispose();
+    });
+
+    // Teardown after all tests
+    suiteTeardown(async () => {
+        // Remove the fake executables that were created
+        await fs.rmdir(userSpecifiedEnvsRoot, { recursive: true });
+
+        sinon.restore();
+    });
+
+    test('iterEnvs(): Windows', async function () {
+        // Skip this test if the OS is not Windows
+        if (getOSType() !== OSType.Windows) {
+            return this.skip();
+        }
+
+        // Configure the user setting to include custom directories
+        pythonConfig
+            .setup((p) => p.get(INTERPRETERS_INCLUDE_SETTING_KEY))
+            .returns(() => [
+                `${userSpecifiedEnvsRoot}\\my\\custom\\dir\\for\\pythons`,
+                `${userSpecifiedEnvsRoot}\\another\\dir\\for\\pythons`,
+            ]);
+
+        // These are the expected environments that should be located
+        const expectedEnvs = userSpecifiedEnvs.executables.map((e: string) => createBasicEnv(PythonEnvKind.Custom, e));
+
+        // Locate the environments and compare them to the expected environments
+        const iterator = locator.iterEnvs();
+        const actualEnvs = await getEnvs(iterator);
+        assertBasicEnvsEqual(actualEnvs, expectedEnvs);
+    });
+
+    test('iterEnvs(): Non-Windows', async function () {
+        // Skip this test on Windows
+        if (getOSType() === OSType.Windows) {
+            return this.skip();
+        }
+
+        // Configure the user setting to include custom directories
+        pythonConfig
+            .setup((p) => p.get(INTERPRETERS_INCLUDE_SETTING_KEY))
+            .returns(() => [
+                `${userSpecifiedEnvsRoot}/my/custom/dir/for/pythons`,
+                `${userSpecifiedEnvsRoot}/another/dir/for/pythons`,
+            ]);
+
+        // These are the expected environments that should be located
+        const expectedEnvs = userSpecifiedEnvs.executables.map((e: string) => createBasicEnv(PythonEnvKind.Custom, e));
+
+        // Locate the environments and compare them to the expected environments
+        const iterator = locator.iterEnvs();
+        const actualEnvs = await getEnvs(iterator);
+        assertBasicEnvsEqual(actualEnvs, expectedEnvs);
+    });
+});

extensions/positron-python/src/test/pythonEnvironments/nativePythonFinder.unit.test.ts

@@ -17,6 +17,7 @@ import * as workspaceApis from '../../client/common/vscodeApis/workspaceApis';
 
 // --- Start Positron ---
 // re-enable when Native Finder is used for discovery
+// TODO: add test for python.interpreters.include here once we switch to Native Finder
 suite.skip('Native Python Finder', () => {
     // --- Find Positron ---
     let finder: NativePythonFinder;