dbt-core-mcp: Instructions file for GitHub Copilot

dbt-core-mcp Testing Standards

Testing Architecture (2-Layer Strategy)

Layer 1: Tool-Specific Comprehensive Tests

• Purpose: Command construction, parameter validation, tool-specific business logic
• Speed Target: < 10 seconds per tool
• Pattern: Mock external dependencies, use real fixtures for parsing validation
• Coverage: All command variations, success/failure scenarios, edge cases
• File: test_tool_{tool_name}.py

Layer 2: Cross-Tool Output Parsing Tests

• Purpose: Validate parsing of dbt output structures across different scenarios
• Speed Target: < 5 seconds total
• Pattern: Real + synthetic fixtures for comprehensive edge case coverage
• Coverage: Success, failure, mixed, empty, skipped results across all tools
• File: test_output_parsing.py (shared validation logic)

Performance Requirements

MANDATORY: All tool test suites must achieve < 10 seconds execution time

Target: Fast, comprehensive testing approach

• ✅ Goal: 3-7 seconds with mock-based + fixture approach

File Organization Standards

Test File Structure

tests/
├── test_tool_{tool_name}.py          # Tool-specific: command + parsing + business logic
├── test_output_parsing.py            # Shared: cross-tool output parsing validation
└── fixtures/
    └── target/
        └── run_results.json          # Real dbt output for parsing tests

Consolidated + Shared Pattern (REQUIRED)

• ✅ Tool-Specific Tests: test_tool_{name}.py with complete tool coverage
• ✅ Shared Output Parsing: test_output_parsing.py for cross-tool validation
• Sections in Tool Tests: Command Construction → Real Fixture Parsing → Business Logic
• Shared Tests: Edge cases (failed, mixed, empty, skipped) + structure validation

Type Safety Standards

Required Type Annotations

from typing import Any, Callable, Dict, Optional
from unittest.mock import Mock

def test_function(mock_state: Mock) -> None:
    async def capture_invoke(args: Dict[str, Any], progress_callback: Optional[Callable[..., Any]] = None) -> Mock:
        # Implementation