# Design: compose-test-sync

## Technical Approach

Fix 3 failing tests by replacing calls to removed/changed compose.py APIs with their current equivalents. Each fix is surgical — only the broken import or call signature changes, no test logic rewrites.

## File Changes

| File | Action | Description |
|------|--------|-------------|
| `tests/test_section_builder.py` | Modify | Replace `root_to_midi` with `NOTE_TO_MIDI` dict lookup |
| `tests/test_render_cli.py` | Modify | Remove obsolete `DrumLoopAnalyzer` patch, retain `SampleSelector` if still needed |
| `tests/test_compose_integration.py` | Modify | Remove `analysis` arg, use section name `"chorus"` instead of `"verse"` |

## Fix Details

### Fix 1: `test_root_to_midi` (test_section_builder.py:121)

**Problem**: Test imports `root_to_midi` which no longer exists in compose.py.
**Fix**: Replace the import and the two assertions.

```python
# Before
from scripts.compose import root_to_midi
assert root_to_midi("A", 4) == 69
assert root_to_midi("C", 4) == 60

# After
from scripts.compose import NOTE_TO_MIDI
assert NOTE_TO_MIDI["A"] + (4 + 1) * 12 == 69
assert NOTE_TO_MIDI["C"] + (4 + 1) * 12 == 60
```

`NOTE_TO_MIDI` is at compose.py:37 and maps `{"A": 69, "C": 60, ...}`. The formula `NOTE_TO_MIDI[root] + (octave + 1) * 12` reconstructs the old `root_to_midi` behavior.

---

### Fix 2: `test_melody_uses_pentatonic` (test_compose_integration.py:200)

**Problem 1**: `build_melody_track` no longer accepts `analysis` as 5th arg.
**Problem 2**: `build_lead_track` (called inside `build_melody_track`) skips any section not named `"chorus"`, `"chorus2"`, or `"final"`. Test passes `"verse"` → zero clips generated.

**Fix**: Remove `analysis` arg from call, change section name to `"chorus"`.

```python
# Before
sections = [SectionDef(name="verse", bars=4, energy=1.0)]
offsets = [0.0]
track = build_melody_track(sections, offsets, "A", True, seed=42)

# After
sections = [SectionDef(name="chorus", bars=4, energy=1.0)]
offsets = [0.0]
track = build_melody_track(sections, offsets, "A", True, seed=42)
```

Note: `analysis = _fake_analysis()` at line 204 becomes unused — leave it in place (no harm) or remove if preferred.

---

### Fix 3: `test_main_without_render_produces_rpp` (test_render_cli.py:44)

**Problem**: Test patches `scripts.compose.DrumLoopAnalyzer` which no longer exists in compose.py.
**Fix**: Remove `patch("scripts.compose.DrumLoopAnalyzer")` from both the mock setup and the with statement.

```python
# Before
with patch("scripts.compose.SampleSelector") as mock_cls, \
     patch("scripts.compose.DrumLoopAnalyzer") as mock_a_cls:

# After
with patch("scripts.compose.SampleSelector") as mock_cls:
```

Lines 48-55 (fake `DrumLoopAnalysis` object) and lines 68-70 (mock analyzer setup) should be removed since `fake_analysis` and `mock_a` are no longer used.

Verify `SampleSelector` patch is still functional — if `SampleSelector` was also removed, remove that patch too and simplify the mock block.

## Verification Strategy

1. Run `pytest tests/ -q` — expect 90/90 pass
2. Run each fixed test individually to confirm:
   - `pytest tests/test_section_builder.py::TestHelpers::test_root_to_midi -v`
   - `pytest tests/test_compose_integration.py::TestComposeIntegration::test_melody_uses_pentatonic -v`
   - `pytest tests/test_render_cli.py::TestComposeNoRender::test_main_without_render_produces_rpp -v`
3. Confirm no compose.py files modified: `git diff --name-only scripts/`

## Open Questions

- **SampleSelector still used?**: Verify `SampleSelector` is still imported/patched in compose.py before leaving that patch in place. If also removed, strip it.
- **None**: All three fixes are clear from the proposal and code inspection.