Merge branch 'main' into copilot/fix-3b6de93e-8dce-49f5-8cd1-5f79d0da7ad8

Author: eleanorjboyd

.github/instructions/testing-workflow.instructions.md

@@ -603,3 +603,4 @@ If that returns 0, re-check compilation path mapping.
 -   Always recompile TypeScript after making import/export changes before running tests, as stubs won't work if they're applied to old compiled JavaScript that doesn't have the updated imports (2)
 -   Create proxy abstraction functions for Node.js APIs like `cp.spawn` to enable clean testing - use function overloads to preserve Node.js's intelligent typing while making the functions mockable (1)
 -   When a targeted test run yields 0 tests, first verify the compiled JS exists under `out/test` (rootDir is `src`); absence almost always means the test file sits outside `src` or compilation hasn't run yet (1)
+-   When unit tests fail with VS Code API errors like `TypeError: X is not a constructor` or `Cannot read properties of undefined (reading 'Y')`, check if VS Code APIs are properly mocked in `/src/test/unittests.ts` - add missing Task-related APIs (`Task`, `TaskScope`, `ShellExecution`, `TaskRevealKind`, `TaskPanelKind`) and namespace mocks (`tasks`) following the existing pattern of `mockedVSCode.X = vscodeMocks.vscMockExtHostedTypes.X` (1)