docs(testing): update testing best practices with performance rules

- document vi.hoisted + vi.mock + static import as the standard pattern
- explicitly ban vi.resetModules, vi.doMock, vi.importActual, mockAuth, setupCommonApiMocks
- document global mocks from vitest.setup.ts
- add mock pattern reference for auth, hybrid auth, and database chains
- add performance rules section covering heavy deps, jsdom vs node, real timers

Author: waleedlatif1

.claude/rules/sim-testing.md

@@ -8,51 +8,210 @@ paths:
 
 Use Vitest. Test files: `feature.ts` → `feature.test.ts`
 
+## Global Mocks (vitest.setup.ts)
+
+These modules are mocked globally — do NOT re-mock them in test files unless you need to override behavior:
+
+- `@sim/db` → `databaseMock`
+- `drizzle-orm` → `drizzleOrmMock`
+- `@sim/logger` → `loggerMock`
+- `@/stores/console/store`, `@/stores/terminal`, `@/stores/execution/store`
+- `@/blocks/registry`
+- `@trigger.dev/sdk`
+
 ## Structure
 
 ```typescript
 /**
  * @vitest-environment node
  */
-import { databaseMock, loggerMock } from '@sim/testing'
-import { describe, expect, it, vi } from 'vitest'
+import { createMockRequest } from '@sim/testing'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { mockGetSession } = vi.hoisted(() => ({
+  mockGetSession: vi.fn(),
+}))
 
-vi.mock('@sim/db', () => databaseMock)
-vi.mock('@sim/logger', () => loggerMock)
+vi.mock('@/lib/auth', () => ({
+  auth: { api: { getSession: vi.fn() } },
+  getSession: mockGetSession,
+}))
 
-import { myFunction } from '@/lib/feature'
+import { GET, POST } from '@/app/api/my-route/route'
 
-describe('myFunction', () => {
-  beforeEach(() => vi.clearAllMocks())
-  it.concurrent('isolated tests run in parallel', () => { ... })
+describe('my route', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockGetSession.mockResolvedValue({ user: { id: 'user-1' } })
+  })
+
+  it('returns data', async () => {
+    const req = createMockRequest('GET')
+    const res = await GET(req)
+    expect(res.status).toBe(200)
+  })
 })
 ```
 
-## @sim/testing Package
+## Performance Rules (Critical)
 
-Always prefer over local mocks.
+### NEVER use `vi.resetModules()` + `vi.doMock()` + `await import()`
 
-| Category | Utilities |
-|----------|-----------|
-| **Mocks** | `loggerMock`, `databaseMock`, `setupGlobalFetchMock()` |
-| **Factories** | `createSession()`, `createWorkflowRecord()`, `createBlock()`, `createExecutorContext()` |
-| **Builders** | `WorkflowBuilder`, `ExecutionContextBuilder` |
-| **Assertions** | `expectWorkflowAccessGranted()`, `expectBlockExecuted()` |
+This is the #1 cause of slow tests. It forces complete module re-evaluation per test.
+
+```typescript
+// BAD — forces module re-evaluation every test (~50-100ms each)
+beforeEach(() => {
+  vi.resetModules()
+  vi.doMock('@/lib/auth', () => ({ getSession: vi.fn() }))
+})
+it('test', async () => {
+  const { GET } = await import('./route')  // slow dynamic import
+})
+
+// GOOD — module loaded once, mocks reconfigured per test (~1ms each)
+const { mockGetSession } = vi.hoisted(() => ({
+  mockGetSession: vi.fn(),
+}))
+vi.mock('@/lib/auth', () => ({ getSession: mockGetSession }))
+import { GET } from '@/app/api/my-route/route'
+
+beforeEach(() => { vi.clearAllMocks() })
+it('test', () => {
+  mockGetSession.mockResolvedValue({ user: { id: '1' } })
+})
+```
+
+**Only exception:** Singleton modules that cache state at module scope (e.g., Redis clients, connection pools). These genuinely need `vi.resetModules()` + dynamic import to get a fresh instance per test.
+
+### NEVER use `vi.importActual()`
+
+This defeats the purpose of mocking by loading the real module and all its dependencies.
+
+```typescript
+// BAD — loads real module + all transitive deps
+vi.mock('@/lib/workspaces/utils', async () => {
+  const actual = await vi.importActual('@/lib/workspaces/utils')
+  return { ...actual, myFn: vi.fn() }
+})
+
+// GOOD — mock everything, only implement what tests need
+vi.mock('@/lib/workspaces/utils', () => ({
+  myFn: vi.fn(),
+  otherFn: vi.fn(),
+}))
+```
+
+### NEVER use `mockAuth()`, `mockConsoleLogger()`, or `setupCommonApiMocks()` from `@sim/testing`
+
+These helpers internally use `vi.doMock()` which is slow. Use direct `vi.hoisted()` + `vi.mock()` instead.
+
+### Mock heavy transitive dependencies
+
+If a module under test imports `@/blocks` (200+ files), `@/tools/registry`, or other heavy modules, mock them:
+
+```typescript
+vi.mock('@/blocks', () => ({
+  getBlock: () => null,
+  getAllBlocks: () => ({}),
+  getAllBlockTypes: () => [],
+  registry: {},
+}))
+```
+
+### Use `@vitest-environment node` unless DOM is needed
+
+Only use `@vitest-environment jsdom` if the test uses `window`, `document`, `FormData`, or other browser APIs. Node environment is significantly faster.
+
+### Avoid real timers in tests
+
+```typescript
+// BAD
+await new Promise(r => setTimeout(r, 500))
+
+// GOOD — use minimal delays or fake timers
+await new Promise(r => setTimeout(r, 1))
+// or
+vi.useFakeTimers()
+```
+
+## Mock Pattern Reference
+
+### Auth mocking (API routes)
+
+```typescript
+const { mockGetSession } = vi.hoisted(() => ({
+  mockGetSession: vi.fn(),
+}))
+
+vi.mock('@/lib/auth', () => ({
+  auth: { api: { getSession: vi.fn() } },
+  getSession: mockGetSession,
+}))
+
+// In tests:
+mockGetSession.mockResolvedValue({ user: { id: 'user-1', email: 'test@example.com' } })
+mockGetSession.mockResolvedValue(null) // unauthenticated
+```
+
+### Hybrid auth mocking
 
-## Rules
+```typescript
+const { mockCheckSessionOrInternalAuth } = vi.hoisted(() => ({
+  mockCheckSessionOrInternalAuth: vi.fn(),
+}))
 
-1. `@vitest-environment node` directive at file top
-2. `vi.mock()` calls before importing mocked modules
-3. `@sim/testing` utilities over local mocks
-4. `it.concurrent` for isolated tests (no shared mutable state)
-5. `beforeEach(() => vi.clearAllMocks())` to reset state
+vi.mock('@/lib/auth/hybrid', () => ({
+  checkSessionOrInternalAuth: mockCheckSessionOrInternalAuth,
+}))
 
-## Hoisted Mocks
+// In tests:
+mockCheckSessionOrInternalAuth.mockResolvedValue({
+  success: true, userId: 'user-1', authType: 'session',
+})
+```
 
-For mutable mock references:
+### Database chain mocking
 
 ```typescript
-const mockFn = vi.hoisted(() => vi.fn())
-vi.mock('@/lib/module', () => ({ myFunction: mockFn }))
-mockFn.mockResolvedValue({ data: 'test' })
+const { mockSelect, mockFrom, mockWhere } = vi.hoisted(() => ({
+  mockSelect: vi.fn(),
+  mockFrom: vi.fn(),
+  mockWhere: vi.fn(),
+}))
+
+vi.mock('@sim/db', () => ({
+  db: { select: mockSelect },
+}))
+
+beforeEach(() => {
+  mockSelect.mockReturnValue({ from: mockFrom })
+  mockFrom.mockReturnValue({ where: mockWhere })
+  mockWhere.mockResolvedValue([{ id: '1', name: 'test' }])
+})
 ```
+
+## @sim/testing Package
+
+Always prefer over local test data.
+
+| Category | Utilities |
+|----------|-----------|
+| **Mocks** | `loggerMock`, `databaseMock`, `drizzleOrmMock`, `setupGlobalFetchMock()` |
+| **Factories** | `createSession()`, `createWorkflowRecord()`, `createBlock()`, `createExecutionContext()` |
+| **Builders** | `WorkflowBuilder`, `ExecutionContextBuilder` |
+| **Assertions** | `expectWorkflowAccessGranted()`, `expectBlockExecuted()` |
+| **Requests** | `createMockRequest()`, `createEnvMock()` |
+
+## Rules Summary
+
+1. `@vitest-environment node` unless DOM is required
+2. `vi.hoisted()` + `vi.mock()` + static imports — never `vi.resetModules()` + `vi.doMock()` + dynamic imports
+3. `vi.mock()` calls before importing mocked modules
+4. `@sim/testing` utilities over local mocks
+5. `beforeEach(() => vi.clearAllMocks())` to reset state — no redundant `afterEach`
+6. No `vi.importActual()` — mock everything explicitly
+7. No `mockAuth()`, `mockConsoleLogger()`, `setupCommonApiMocks()` — use direct mocks
+8. Mock heavy deps (`@/blocks`, `@/tools/registry`, `@/triggers`) in tests that don't need them
+9. Use absolute imports in test files
+10. Avoid real timers — use 1ms delays or `vi.useFakeTimers()`