proffesor-for-testing__agentic-qe/docs/fixes/mcp-test-mocking-fix-1.md

MCP Test Mocking Fix - Part 1

Date: 2025-10-21 Status: ✅ Partial Fix - QEAgentFactory Constructor Error Resolved Remaining: Logger mock issues and test logic failures

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Problem Identified

All MCP tests (78 test cases across 2 files) were failing with:

TypeError: agents_1.QEAgentFactory is not a constructor
  at new AgentRegistry (src/mcp/services/AgentRegistry.ts:81:20)

Root Cause

In jest.setup.ts lines 85-97, there was a global mock for './src/agents' that only exported createAgent:

// BEFORE (broken)
jest.mock('./src/agents', () => ({
  createAgent: jest.fn().mockImplementation((type, config, services) => ({
    // ...mock implementation
  }))
}));

When AgentRegistry tried to import QEAgentFactory from '../../agents', Jest intercepted this with the global mock, which didn't include QEAgentFactory, making it undefined.

Solution Applied

Updated jest.setup.ts to preserve all actual exports while mocking createAgent:

// AFTER (fixed)
jest.mock('./src/agents', () => {
  const actual = jest.requireActual('./src/agents');
  return {
    ...actual, // Preserve all actual exports including QEAgentFactory
    createAgent: jest.fn().mockImplementation((type, config, services) => ({
      id: `agent-${Math.random().toString(36).substring(7)}`,
      type,
      config,
      status: 'idle',
      initialize: jest.fn().mockResolvedValue(undefined),
      assignTask: jest.fn().mockResolvedValue(undefined),
      terminate: jest.fn().mockResolvedValue(undefined),
      getStatus: jest.fn().mockReturnValue({ status: 'idle' }),
      execute: jest.fn().mockResolvedValue({ success: true })
    }))
  };
});

Results

✅ Fixed: QEAgentFactory is not a constructor error eliminated ✅ Impact: All MCP tests now load correctly without constructor errors ⚠️ Remaining Issues:

1. Logger mock not working in AgentRegistry: Cannot read properties of undefined (reading 'info')
2. Test logic failures: All tests expect result.success = true but getting false

Test Output Analysis

Before Fix:

• 25/25 tests failing with constructor error
• Tests couldn't even initialize server

After Fix:

• 0/25 constructor errors ✅
• 25/25 tests failing with logic/mock issues (different error)
• Server initializes successfully ✅

Next Steps

1. Fix logger mock in AgentRegistry to use the global mock correctly
2. Investigate why all handler methods are returning success: false
3. Add proper error handling mocks for MCP handlers
4. Update test expectations to match actual handler behavior

Files Modified

• /workspaces/agentic-qe-cf/jest.setup.ts (lines 85-102)

Lessons Learned

1. Global mocks affect all imports: When using jest.mock() in setup files, it applies to ALL test files
2. Preserve actual exports: Use jest.requireActual() to preserve real exports while mocking specific functions
3. Spread operator for safety: ...actual ensures all exports are available even if we don't know what they are

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Session: Release 1.2.0 Test Fixes - Part 2 Author: Claude Code Next Task: Fix logger mock and handler test logic