Add support for Projects in Testing #25780

eleanorjboyd · 2026-02-09T21:04:38Z

fixes microsoft/vscode-python-environments#987

## Summary This PR implements **project-based test discovery** for pytest, enabling multi-project workspace support. When the Python Environments API is available, the extension now discovers Python projects within workspaces and creates separate test tree roots for each project with its own Python environment. ## What's New ### Project-Based Testing Architecture - **TestProjectRegistry**: Manages the lifecycle of Python test projects, including: - Discovering projects via Python Environments API - Creating ProjectAdapter instances per workspace - Computing nested project relationships for ignore lists - Fallback to "legacy" single-adapter mode when API unavailable - **ProjectAdapter**: Interface representing a single Python project with test infrastructure: - Project identity (ID, name, URI) - Python environment from the environments API - Test framework adapters (discovery/execution) - Nested project ignore paths ### Key Features - ✅ **Multi-project workspaces**: Each Python project gets its own test tree root - ✅ **Nested project handling**: Parent projects automatically ignore nested child projects via `--ignore` flags - ✅ **Graceful fallback**: Falls back to legacy single-adapter mode if Python Environments API is unavailable - ✅ **Project root path**: Python-side `get_test_root_path()` function returns appropriate root for test tree ### Code Improvements - Standardized logging prefixes to `[test-by-project]` across all files - Centralized adapter creation via `createTestAdapters()` helper method - Extracted reusable methods for discovery, execution, and file watching ## Scope & Limitations > **⚠️ Important: unittest is NOT supported in this PR** > > This PR focuses exclusively on **pytest**. unittest support for project-based testing will be implemented in a future PR. ## Testing - Added unit tests for `TestProjectRegistry` class - Added unit tests for Python-side `get_test_root_path()` function - Manual testing with multi-project workspaces ## Related Issues first step in: microsoft/vscode-python-environments#987 --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

This adds a place within the github workspace that developers can store any AI related artifacts they create that could be useful but they don't want to commit. Things like issue summarization, plans for features, code analysis etc

Copilot

Pull request overview

This PR adds project-based (multi-project) testing support to the VS Code Python extension’s Test Explorer integration, leveraging the Python Environments API so each project can be discovered/run/debugged with its own environment (fixes microsoft/vscode-python-environments#987).

Changes:

Introduces a project registry + project adapter model to discover/register multiple Python projects per workspace and run discovery/execution per project.
Scopes VS Code test IDs by project (via a project ID separator) and threads project context through discovery/execution adapters (including PROJECT_ROOT_PATH support in Python runner scripts).
Adds extensive unit tests (TS + Python) covering project-based discovery/execution, nested project behavior, and debug session handling.

Reviewed changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/client/testing/testController/controller.ts	Adds project-based activation/discovery/execution flow and project-change handling.
src/client/testing/testController/common/testProjectRegistry.ts	New registry for discovering projects, creating project-specific adapters/resolvers, and nested ignore computation.
src/client/testing/testController/common/projectAdapter.ts	Defines per-project adapter shape (env + adapters + resolver + lifecycle).
src/client/testing/testController/common/projectUtils.ts	Adds project ID scoping utilities + shared adapter creation helper.
src/client/testing/testController/common/projectTestExecution.ts	Executes selected tests grouped by owning project with project-specific environment/debug/coverage behavior.
src/client/testing/testController/common/utils.ts	Adds project-scoped IDs in `populateTestTree()` and project-aware error labels.
src/client/testing/testController/common/testDiscoveryHandler.ts	Routes discovery into project-scoped IDs and project-scoped error nodes.
src/client/testing/testController/pytest/pytestDiscoveryAdapter.ts	Threads `ProjectAdapter` through discovery; adds nested `--ignore` support; sets `PROJECT_ROOT_PATH`.
src/client/testing/testController/pytest/pytestExecutionAdapter.ts	Threads `ProjectAdapter` through execution; uses project env when available; sets `PROJECT_ROOT_PATH`.
src/client/testing/testController/unittest/testDiscoveryAdapter.ts	Threads `ProjectAdapter` through discovery; uses project env when available; sets `PROJECT_ROOT_PATH`.
src/client/testing/testController/unittest/testExecutionAdapter.ts	Threads `ProjectAdapter` through execution/debug; uses project env when available; sets `PROJECT_ROOT_PATH`.
src/client/testing/testController/workspaceTestAdapter.ts	Allows passing a `ProjectAdapter` to execution for project-scoped runs.
src/client/testing/common/debugLauncher.ts	Adds multi-session tracking via markers; supports project-based debug naming + Python path resolution.
python_files/vscode_pytest/init.py	Uses `PROJECT_ROOT_PATH` to root discovery/execution payload cwd/test-tree root for project mode.
python_files/unittestadapter/discovery.py	Supports `PROJECT_ROOT_PATH` to override cwd/top-level behavior for project-rooted discovery.
python_files/unittestadapter/execution.py	Supports `PROJECT_ROOT_PATH` to override cwd in execution payloads.
src/test/vscode-mock.ts	Adds `vscode.tests.createTestController()` mock for unit tests.
src/test/testing/testController/**	Adds unit tests for project registry, project execution grouping, controller behavior, adapters, and utilities.
python_files/tests/**	Adds Python-side tests for `PROJECT_ROOT_PATH` behavior for both unittest + pytest.
.github/instructions/testing_feature_area.instructions.md	Documents the new project-based testing architecture and key files/tests.

Copilot · 2026-02-09T22:01:24Z

src/client/testing/common/debugLauncher.ts

+        // Start the debug session
+        const started = await debugManager.startDebugging(workspaceFolder, launchArgs, sessionOptions);
+        if (!started) {
+            traceError('Failed to start debug session');
+            deferred.resolve();
+            callCallbackOnce();
+        }
+
+        // Clean up event subscriptions when debugging completes (success, failure, or cancellation)
+        deferred.promise.finally(() => {
+            disposables.forEach((d) => d.dispose());
        });
+


launchDebugger() awaits debugManager.startDebugging(...) without a try/catch. If startDebugging rejects/throws, this method will throw and never resolve deferred, and the event subscriptions in disposables won’t be disposed (potential leak + hung callers). Wrap the startDebugging await in a try/catch, resolve/reject the deferred appropriately, and ensure disposables are always cleaned up (e.g., in a finally block).

Suggested change

// Start the debug session

const started = await debugManager.startDebugging(workspaceFolder, launchArgs, sessionOptions);

if (!started) {

traceError('Failed to start debug session');

deferred.resolve();

callCallbackOnce();

}

// Clean up event subscriptions when debugging completes (success, failure, or cancellation)

deferred.promise.finally(() => {

disposables.forEach((d) => d.dispose());

});

// Clean up event subscriptions when debugging completes (success, failure, or cancellation)

deferred.promise.finally(() => {

disposables.forEach((d) => d.dispose());

});

// Start the debug session

let started = false;

try {

started = await debugManager.startDebugging(workspaceFolder, launchArgs, sessionOptions);

} catch (error) {

traceError('Error starting debug session', error);

deferred.reject(error);

callCallbackOnce();

return deferred.promise;

}

if (!started) {

traceError('Failed to start debug session');

deferred.resolve();

callCallbackOnce();

}

Copilot · 2026-02-09T22:01:24Z

src/client/testing/testController/common/testProjectRegistry.ts

+                const parentPath = parent.projectUri.fsPath;
+                const childPath = child.projectUri.fsPath;
+
+                if (childPath.startsWith(parentPath + path.sep)) {


Nested project detection uses childPath.startsWith(parentPath + path.sep), which is not case-normalized and can mis-detect relationships on Windows (and can be tripped up by path normalization differences). Since this file already imports isParentPath, use that helper (and keep the self-check) to compute nested projects reliably across platforms.

Suggested change

if (childPath.startsWith(parentPath + path.sep)) {

if (isParentPath(parentPath, childPath)) {

Copilot · 2026-02-09T22:01:24Z

src/client/testing/testController/controller.ts

+            // Clear registry and re-discover all projects for the workspace
+            this.projectRegistry.clearWorkspace(workspace.uri);
+            await this.projectRegistry.discoverAndRegisterProjects(workspace.uri);
+
+            // Re-run test discovery for the workspace to populate fresh test items
+            await this.discoverTestsInWorkspace(workspace.uri);


handleProjectChanges() clears and re-discovers projects via projectRegistry.discoverAndRegisterProjects(...), then calls discoverTestsInWorkspace(), which (in project mode) calls discoverAllProjectsInWorkspace() and re-discovers projects again (it clears + re-registers internally). This duplicates work and can cause unnecessary churn (extra API calls + extra test item cleanup). Consider letting discoverAllProjectsInWorkspace() be the single place that clears/re-registers, and in handleProjectChanges() just do the minimal cleanup + call discoverAllProjectsInWorkspace(workspace.uri) directly (or skip the pre-registration step).

Suggested change

// Clear registry and re-discover all projects for the workspace

this.projectRegistry.clearWorkspace(workspace.uri);

await this.projectRegistry.discoverAndRegisterProjects(workspace.uri);

// Re-run test discovery for the workspace to populate fresh test items

await this.discoverTestsInWorkspace(workspace.uri);

// Re-discover all projects and tests for the workspace in a single pass.

// discoverAllProjectsInWorkspace is responsible for clearing/re-registering

// projects and performing test discovery for the workspace.

await this.discoverAllProjectsInWorkspace(workspace.uri);

eleanorjboyd and others added 6 commits February 5, 2026 21:37

Thick-puffin (#25768)

2d53b1f

Unittest discovery with py-env Projects Support (#25767)

5104ff6

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

fix bug with double error nodes

42fb7b7

Add python-environment's project support for pytest execution (#25772)

3b87651

eleanorjboyd added the feature-request Request for new features or functionality label Feb 9, 2026

eleanorjboyd self-assigned this Feb 9, 2026

eleanorjboyd added 2 commits February 9, 2026 13:48

Python Environments Project Support for Unittest Execution (#25779)

f048ef4

Merge branch 'main' into test-project-support

0cfd96d

eleanorjboyd requested a review from Copilot February 9, 2026 21:54

eleanorjboyd marked this pull request as ready for review February 9, 2026 21:54

eleanorjboyd requested review from anthonykim1 and karthiknadig February 9, 2026 21:54

Copilot started reviewing on behalf of eleanorjboyd February 9, 2026 21:55 View session

vs-code-engineering bot added this to the February 2026 milestone Feb 9, 2026

Copilot AI reviewed Feb 9, 2026

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Add support for Projects in Testing #25780

Add support for Projects in Testing #25780

eleanorjboyd commented Feb 9, 2026 •

edited

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	if (childPath.startsWith(parentPath + path.sep)) {
	if (isParentPath(parentPath, childPath)) {

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eleanorjboyd commented Feb 9, 2026 •

edited

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