feat: add tests and helper for using run.executable for interpreter not activatedRun

Author: eleanorjboyd

.github/copilot-instructions.md

@@ -0,0 +1,5 @@
+# Copilot Instructions for vscode-python-debugger
+
+## Learnings
+
+-   Always use `run.executable` (the actual Python binary path) instead of `activatedRun.executable` for interpreter identification in `getInterpreterDetails`, `getSettingsPythonPath`, and `getExecutableCommand`. `activatedRun.executable` may be a wrapper command (e.g. `pixi run python`) set by environment managers like pixi or conda, which breaks the debugger if used as a replacement for the binary. (1)

src/test/unittest/adapter/factory.unit.test.ts

@@ -32,6 +32,7 @@ import * as telemetryReporter from '../../../extension/telemetry/reporter';
 import * as vscodeApi from '../../../extension/common/vscodeapi';
 import { DebugConfigStrings } from '../../../extension/common/utils/localize';
 import { PythonEnvironment } from '../../../extension/envExtApi';
+import { buildPythonEnvironmentWithActivatedRun } from '../common/helpers';
 
 use(chaiAsPromised);
 
@@ -340,4 +341,27 @@ suite('Debugging - Adapter Factory', () => {
 
         assert.deepStrictEqual(descriptor, debugExecutable);
     });
+
+    test('Use run.executable rather than activatedRun.executable for interpreter identification', async () => {
+        // Simulates environment managers like pixi/conda that set activatedRun to a wrapper
+        // command (e.g. "pixi run python") while run.executable is the actual Python binary.
+        const actualPythonPath = 'path/to/actual/python3';
+        const wrapperCommand = 'pixi';
+        const interpreterWithWrapper = buildPythonEnvironmentWithActivatedRun(
+            actualPythonPath,
+            wrapperCommand,
+            '3.10.0',
+            ['run', 'python'],
+        );
+        const session = createSession({});
+        // The debug adapter should use the actual Python binary, not the wrapper
+        const debugExecutable = new DebugAdapterExecutable(interpreterWithWrapper.execInfo.run.executable, [
+            debugAdapterPath,
+        ]);
+        getInterpreterDetailsStub.resolves({ path: [interpreterWithWrapper.execInfo.run.executable] });
+        resolveEnvironmentStub.resolves(interpreterWithWrapper);
+        const descriptor = await factory.createDebugAdapterDescriptor(session, nodeExecutable);
+
+        assert.deepStrictEqual(descriptor, debugExecutable);
+    });
 });

src/test/unittest/common/helpers.ts

@@ -28,3 +28,45 @@ export function buildPythonEnvironment(execPath: string, version: string, sysPre
         sysPrefix,
     } as PythonEnvironment;
 }
+
+/**
+ * Helper to build a PythonEnvironment where activatedRun differs from run.
+ * This simulates environment managers like pixi or conda that set activatedRun
+ * to a wrapper command (e.g. 'pixi run python') while run.executable points to
+ * the actual Python binary.
+ *
+ * @param execPath string - path to the actual python executable (run.executable)
+ * @param activatedRunExecutable string - path/command for the wrapper (activatedRun.executable)
+ * @param version string - python version string (e.g. '3.9.0')
+ * @param activatedRunArgs string[] - optional args for activatedRun
+ */
+export function buildPythonEnvironmentWithActivatedRun(
+    execPath: string,
+    activatedRunExecutable: string,
+    version: string,
+    activatedRunArgs: string[] = [],
+): PythonEnvironment {
+    const execUri = Uri.file(execPath);
+    return {
+        envId: {
+            id: execUri.fsPath,
+            managerId: 'Venv',
+        },
+        name: `Python ${version}`,
+        displayName: `Python ${version}`,
+        displayPath: execUri.fsPath,
+        version: version,
+        environmentPath: execUri,
+        execInfo: {
+            run: {
+                executable: execUri.fsPath,
+                args: [],
+            },
+            activatedRun: {
+                executable: activatedRunExecutable,
+                args: activatedRunArgs,
+            },
+        },
+        sysPrefix: '',
+    } as PythonEnvironment;
+}

src/test/unittest/common/pythonTrue.unit.test.ts

@@ -9,7 +9,7 @@ import { Uri, Disposable, Extension, extensions } from 'vscode';
 import * as path from 'path';
 import * as pythonApi from '../../../extension/common/python';
 import * as utilities from '../../../extension/common/utilities';
-import { buildPythonEnvironment } from './helpers';
+import { buildPythonEnvironment, buildPythonEnvironmentWithActivatedRun } from './helpers';
 
 // Platform-specific path constants using path.join so tests assert using native separators.
 // Leading root '/' preserved; on Windows this yields a leading backslash (e.g. '\\usr\\bin').
@@ -166,6 +166,24 @@ suite('Python API Tests- useEnvironmentsExtension:true', () => {
 
             expect(result).to.be.undefined;
         });
+
+        test('Should use run.executable instead of activatedRun.executable when they differ', async () => {
+            // Simulates environment managers like pixi/conda that set activatedRun to a wrapper command
+            const actualPythonPath = PYTHON_PATH;
+            const wrapperCommand = path.join('/', 'usr', 'local', 'bin', 'pixi');
+            const mockPythonEnv = buildPythonEnvironmentWithActivatedRun(actualPythonPath, wrapperCommand, '3.9.0', [
+                'run',
+                'python',
+            ]);
+            (mockEnvsExtension as any).exports = mockPythonEnvApi;
+            mockPythonEnvApi.getEnvironment.resolves(mockPythonEnv);
+            mockPythonEnvApi.resolveEnvironment.resolves(mockPythonEnv);
+
+            const result = await pythonApi.getSettingsPythonPath();
+
+            // Should return the actual Python binary path, not the wrapper command
+            expect(result).to.deep.equal([actualPythonPath]);
+        });
     });
 
     suite('getEnvironmentVariables', () => {
@@ -374,6 +392,26 @@ suite('Python API Tests- useEnvironmentsExtension:true', () => {
 
             expect(result.path).to.be.undefined;
         });
+
+        test('Should use run.executable instead of activatedRun.executable when they differ', async () => {
+            // Simulates environment managers like pixi/conda that set activatedRun to a wrapper command
+            const actualPythonPath = PYTHON_PATH;
+            const wrapperCommand = path.join('/', 'usr', 'local', 'bin', 'pixi');
+            const mockEnv = buildPythonEnvironmentWithActivatedRun(actualPythonPath, wrapperCommand, '3.9.0', [
+                'run',
+                'python',
+            ]);
+
+            (mockEnvsExtension as any).exports = mockPythonEnvApi;
+            mockPythonEnvApi.getEnvironment.returns({ environmentPath: Uri.file(actualPythonPath) });
+            mockPythonEnvApi.resolveEnvironment.resolves(mockEnv);
+
+            const result = await pythonApi.getInterpreterDetails();
+
+            // Should return the actual Python binary path, not the wrapper command
+            expect(result.path).to.deep.equal([actualPythonPath]);
+            expect(result.resource).to.be.undefined;
+        });
     });
 
     suite('onDidChangePythonInterpreter event', () => {