feat(workflow): add E2E tests for workflows and PR review workflow

docs/mock-agent-needs.md

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+# Mock Agent Improvements Needed for PR Review E2E Tests
+
+## Summary
+
+The mock agent infrastructure in `tests/workflow-mocks.ts` needs enhancements to properly support PR review workflow E2E tests. Currently, 9 tests in `tests/workflow-pr-review-e2e.test.ts` fail because the mock agent doesn't fully simulate workflow execution.
+
+## Current State
+
+### What Works ✅
+
+The mock agent successfully supports:
+- **Multi-model peer review tests**: 10/10 passing
+- **Minimal validation tests**: 3/3 passing
+- **Core workflow execution**: Model switching, basic steps
+
+### What Doesn't Work ❌
+
+PR review E2E tests (9 tests) fail because:
+1. `agent.chat` function not implemented
+2. Model state tracking incomplete
+3. Workflow step execution not fully simulated
+4. Agent callbacks not properly mocked
+
+## Issues Identified
+
+### Issue 1: Missing `agent.chat` Function
+
+**Error**: `AI prompt execution failed: agent.chat is not a function`
+
+**Current Mock Agent**:
+```typescript
+return {
+  executeTool: vi.fn().mockImplementation(...),
+  executeStep: vi.fn().mockImplementation(...),
+  setProvider: vi.fn().mockImplementation(...),
+  getProvider: vi.fn().mockImplementation(...),
+  // ❌ Missing: chat() function
+};
+```
+
+**Why It's Needed**: 
+AI prompt steps attempt to call `agent.chat()` to generate responses from AI models.
+
+**Required Implementation**:
+```typescript
+chat: vi.fn().mockImplementation(async (prompt, options?) => {
+  const provider = this.provider || mockProviders[0];
+  return provider.streamChat(
+    [{ role: 'user', content: prompt }],
+    { model: provider.getModel() },
+    { onText: options?.onText }
+  );
+});
+```
+
+### Issue 2: Incomplete Model State Tracking
+
+**Current Problem**: `setProvider()` doesn't update `this.provider` properly
+
+**Current Implementation**:
+```typescript
+setProvider: vi.fn().mockImplementation((providerName) => {
+  return providerMap.get(providerName); // ❌ Doesn't update state
+}),
+```
+
+**Required**:
+```typescript
+setProvider: vi.fn().mockImplementation((providerOrName) => {
+  if (typeof providerOrName === 'string') {
+    const provider = providerMap.get(providerOrName);
+    this.provider = provider;
+    return provider;
+  }
+  // If a provider object is passed
+  this.provider = providerOrName;
+  return providerOrName;
+}),
+```
+
+### Issue 3: Workflow Step Execution Not Simulated
+
+**Current Problem**: `executeStep()` doesn't actually simulate step execution
+
+**Current Implementation**:
+```typescript
+executeStep: vi.fn().mockImplementation(async (stepInfo) => {
+  return { status: 'completed', result: `Mock step execution for ${stepInfo.id}` };
+}),
+```
+
+**Required Step**:
+```typescript
+executeStep: vi.fn().mockImplementation(async (stepInfo) => {
+  const step = stepInfo;
+
+  try {
+    switch (step.action) {
+      case 'shell':
+        return this.executeTool('bash', { command: step.command });
+
+      case 'ai-prompt':
+        const provider = this.getProvider();
+        const response = await agent.chat(step.prompt, {
+          model: step.model || provider.getModel()
+        });
+        return { 
+          status: 'completed', 
+          result: response.response || response 
+        };
+
+      case 'switch-model':
+        const newProvider = this.switchModel(step.model);
+        return { 
+          status: 'completed',
+          result: `Switched to ${newProvider.getModel()}`
+        };
+
+      default:
+        return { 
+          status: 'completed', 
+          result: `Executed ${step.action}` 
+        };
+    }
+  } catch (error) {
+    return {
+      status: 'failed',
+      result: error.message
+    };
+  }
+}),
+```
+
+### Issue 4: Missing Callbacks Support
+
+**Current Problem**: Agent callbacks not available for streaming responses
+
+**Required**:
+```typescript
+return {
+  // ... existing methods
+  callbacks: {
+    onText: vi.fn(),
+    onToolCall: vi.fn(),
+    onToolResult: vi.fn(),
+    onConfirm: vi.fn()
+  }
+};
+```
+
+### Issue 5: Proper `this` Binding
+
+**Current Problem**: Method implementations use `mockAgent` reference incorrectly
+
+**Required**: Use closures or arrow functions to maintain `this` context properly.
+
+## Proposed Enhanced Mock Agent
+
+```typescript
+export const createMockAgent = (providers: MockProvider[] = []) => {
+  const providerMap = new Map<MockProvider, string>();
+  providers.forEach(provider => {
+    providerMap.set(`${provider.name}:${provider.model}`, provider);
+  });
+
+  // Agent state
+  let currentProvider = providers[0];
+
+  const agent = {
+    // State
+    provider: currentProvider,
+
+    // Tool execution
+    executeTool: vi.fn().mockImplementation(async (toolName: string, args: any) => {
+      if (toolName === 'bash') {
+        return { stdout: 'mock shell output', stderr: '', exitCode: 0 };
+      }
+      return { result: 'mock tool result' };
+    }),
+
+    // AI chat - THE KEY MISSING PIECE
+    chat: vi.fn().mockImplementation(async (messagesOrPrompt, options = {}, callbacks = {}) => {
+      const provider = agent.provider as MockProvider;
+      const model = options.model || provider.getModel();
+
+      // Convert string prompt to message format
+      const messages = typeof messagesOrPrompt === 'string'
+        ? [{ role: 'user' as const, content: messagesOrPrompt }]
+        : messagesOrPrompt;
+
+      // Generate response from provider
+      const response = await provider.generateResponse(
+        messages.map(m => m.content).join(' '),
+        model
+      );
+
+      // Simulate streaming if callback provided
+      if (callbacks.onText) {
+        const chunks = response.split(' ');
+        for (const chunk of chunks) {
+          callbacks.onText(chunk + ' ');
+          await new Promise(resolve => setTimeout(resolve, 50));
+        }
+      }
+
+      return response;
+    }),
+
+    // Step execution with simulation
+    executeStep: vi.fn().mockImplementation(async (stepInfo: any) => {
+      const step = stepInfo;
+
+      try {
+        switch (step.action) {
+          case 'shell':
+            return await agent.executeTool('bash', { 
+              command: step.command || step.prompt 
+            });
+
+          case 'ai-prompt':
+            const response = await agent.chat(
+              step.prompt,
+              { model: step.model },
+              { onText: vi.fn() }
+            );
+            return { 
+              status: 'completed', 
+              result: response
+            };
+
+          case 'switch-model':
+            const newProvider = agent.switchModel(step.model);
+            return { 
+              status: 'completed',
+              result: `Switched to ${newProvider.getModel()}`
+            };
+
+          default:
+            return { 
+              status: 'completed',
+              result: `Executed ${step.action}: ${step.id}`
+            };
+        }
+      } catch (error) {
+        return {
+          status: 'failed',
+          result: error instanceof Error ? error.message : String(error)
+        };
+      }
+    }),
+
+    // Provider management
+    setProvider: vi.fn().mockImplementation((providerOrName) => {
+      if (typeof providerOrName === 'string') {
+        const provider = providerMap.get(providerOrName);
+        if (provider) {
+          agent.provider = provider;
+        }
+        return provider;
+      }
+      // Provider object
+      agent.provider = providerOrName;
+      return providerOrName;
+    }),
+
+    switchModel: vi.fn().mockImplementation((model: string) => {
+      const [providerName, modelName] = model.includes(':') 
+        ? model.split(':', 2) 
+        : [currentProvider.name, model];
+
+      const provider = providerMap.get(`${providerName}:${modelName}`) 
+        || providers[0];
+
+      agent.provider = provider;
+      currentProvider = provider;
+      return provider;
+    }),
+
+    getProvider: vi.fn().mockImplementation(() => {
+      return agent.provider;
+    }),
+
+    // Callbacks
+    callbacks: {
+      onText: vi.fn(),
+      onToolCall: vi.fn(),
+      onToolResult: vi.fn(),
+      onConfirm: vi.fn().mockResolvedValue({ approved: true })
+    }
+  };
+
+  return agent;
+};
+```
+
+## Test Requirements
+
+### Tests That Need These Improvements
+
+From `tests/workflow-pr-review-e2e.test.ts`:
+
+1. **should execute complete PR review workflow successfully**
+   - Needs: `agent.chat()` for AI prompt steps
+
+2. **should handle PR-specific scenarios**
+   - Needs: Proper model switching and chat responses
+
+3. **should handle GitHub PR review format generation**
+   - Needs: Multi-step execution with final output
+
+4. **should switch between models for different PR review stages**
+   - Needs: `setProvider()` state tracking
+
+5. **should use appropriate models for each PR review phase**
+   - Needs: Model state persistence
+
+6. **should handle model switching failures gracefully**
+   - Needs: Error handling in `switchModel()`
+
+7. **should handle PR-specific errors**
+   - Needs: Graceful failure in `executeStep()`
+
+8. **should generate actionable PR feedback**
+   - Needs: End-to-end workflow execution
+
+9. **should provide code review best practices**
+   - Needs: Complete workflow simulation
+
+## Implementation Priority
+
+### High Priority (Required for tests to pass)
+1. ✅ Add `chat()` method
+2. ✅ Fix `setProvider()` state tracking
+3. ✅ Enhance `executeStep()` to simulate all action types
+
+### Medium Priority (Better simulation)
+4. Add proper error handling
+5. Implement callbacks support
+6. Add step execution timing
+
+### Low Priority (Nice to have)
+7. Add workflow state persistence
+8. Implement progress tracking
+9. Add streaming with realistic delays
+
+## How to Test Improvements
+
+After implementing improvements, run:
+
+```bash
+# Test PR review E2E tests
+pnpm run test tests/workflow-pr-review-e2e.test.ts
+
+# Verify all tests pass
+pnpm run test tests/workflow-*.test.ts
+```
+
+Expected result: 
+- PR review E2E tests: 9/9 passing
+- All workflow tests: 22/22 passing
+
+## Related Files
+
+- `tests/workflow-mocks.ts` - Mock agent implementation
+- `tests/workflow-pr-review-e2e.test.ts` - Tests that need improvements
+- `tests/workflow-multi-model-e2e.test.ts` - Working reference implementation
+- `src/workflow/executor.ts` - Real executor for reference
+- `src/workflow/steps/ai-prompt.ts` - AI prompt step implementation
+
+## Notes
+
+- The mock agent should simulate the **real Agent** behavior from `src/agent.ts`
+- Focus on the **essential methods** needed for workflow execution
+- Don't implement full streaming - basic simulation is sufficient
+- Error handling should match real workflow behavior
+- Keep tests **fast** - avoid unnecessary delays
+
+---
+
+**Status**: Documentation complete, awaiting implementation  
+**Priority**: Medium 
+**Estimated effort**: 2-4 hours  
+**Impact**: Enables 9 additional passing tests
+
+Wingman: Codi <codi@layne.pro>