# Phase 03-03: MCP CLI Subcommand and Unit Tests - Summary

## Completed Tasks

### Task 1: Add corpus mcp serve CLI subcommand
- Added `mcp_app` Typer sub-application to `src/corpus_analyzer/cli.py`
- Added `mcp_serve` command with lazy import of the MCP server
- Verified `corpus mcp serve --help` works correctly
- Committed as `5c4d9fc`

### Task 2: Write MCP server unit tests
- Created `tests/mcp/__init__.py` - Test package initializer
- Created `tests/mcp/test_server.py` with 5 tests:
  - `test_corpus_search_returns_results_shape()` - Verifies result dict has required fields
  - `test_corpus_search_empty_results()` - Verifies empty results return correct message
  - `test_corpus_search_engine_none_raises_value_error()` - Verifies error when engine is None
  - `test_corpus_search_passes_filters_to_hybrid_search()` - Verifies filters are passed through
  - `test_server_module_does_not_write_to_stdout()` - Verifies no stdout writes (MCP-04)
- Committed as `69f5427`

### Task 3: Write Python API unit tests
- Created `tests/api/__init__.py` - Test package initializer
- Created `tests/api/test_public.py` with 6 tests:
  - `test_search_result_has_required_fields()` - Verifies SearchResult has 6 fields
  - `test_search_result_instantiation()` - Verifies SearchResult can be instantiated
  - `test_search_calls_hybrid_search_and_maps_to_dataclasses()` - Verifies search() delegates
  - `test_search_passes_filters_to_hybrid_search()` - Verifies filters are passed through
  - `test_index_calls_index_source_for_each_source()` - Verifies index() calls index_source
  - `test_find_config_walks_up_from_cwd()` - Verifies config discovery walks up from CWD
- Committed as `936f4e7`

### Task 4: Final verification
- Fixed pre-existing test that expected old docstring
- All verification checks passed:
  - `uv run pytest tests/mcp/ tests/api/ -v` - 11 tests passed
  - `uv run pytest -x -q` - 164 tests passed (no regressions)
  - `uv run mypy src/corpus_analyzer/mcp/ src/corpus_analyzer/api/ src/corpus/ src/corpus_analyzer/cli.py` - clean
  - `uv run ruff check src/corpus_analyzer/mcp/ src/corpus_analyzer/api/ src/corpus/ tests/mcp/ tests/api/` - clean
  - `uv run corpus --help` - shows `mcp` as a subcommand group

## Success Criteria Met

- `corpus mcp serve --help` works; `corpus mcp serve` would start the FastMCP stdio server ✓
- `tests/mcp/test_server.py` tests: response shape, empty results, engine-None error, filter passthrough, stdout isolation ✓
- `tests/api/test_public.py` tests: SearchResult fields, search() delegation, index() indexing, _find_config() walk-up ✓
- All Phase 3 tests pass (11/11) ✓
- No regressions in Phase 1/2 tests (164/164) ✓
- All Phase 3 requirement IDs (MCP-01 through MCP-06, API-01 through API-03) satisfied end-to-end ✓

## Commits

1. `5c4d9fc` - feat(cli): add corpus mcp serve subcommand
2. `69f5427` - test(mcp): add unit tests for corpus_search tool
3. `936f4e7` - test(api): add unit tests for search, index, and SearchResult

## Phase 03 Complete

All three plans (03-01, 03-02, 03-03) are now complete:
- MCP server with FastMCP and corpus_search tool
- Python public API with search() and index() functions
- CLI subcommand and comprehensive unit tests

Proceed to next phase as defined in the roadmap.
