StarPunk/docs/design/v1.0.0/custom-slug-bug-implementation.md

# Custom Slug Bug Fix - Implementation Report

**Date**: 2025-11-25
**Developer**: StarPunk Developer Subagent
**Branch**: bugfix/custom-slug-extraction
**Status**: Complete - Ready for Testing

## Executive Summary

Successfully fixed the custom slug extraction bug in the Micropub handler. Custom slugs specified via `mp-slug` parameter are now correctly extracted and used when creating notes.

## Problem Statement

Custom slugs specified via the `mp-slug` property in Micropub requests were being completely ignored. The system was falling back to auto-generated slugs even when a custom slug was provided by the client (e.g., Quill).

**Root Cause**: `mp-slug` was being extracted from normalized properties after it had already been filtered out by `normalize_properties()` which removes all `mp-*` parameters.

## Implementation Details

### Files Modified

1. **starpunk/micropub.py** (lines 290-307)
   - Moved `mp-slug` extraction to BEFORE property normalization
   - Added support for both form-encoded and JSON request formats
   - Added clear comments explaining the timing requirement

2. **tests/test_micropub.py** (added lines 191-246)
   - Added `test_micropub_create_with_custom_slug_form()` - tests form-encoded requests
   - Added `test_micropub_create_with_custom_slug_json()` - tests JSON requests
   - Both tests verify the custom slug is actually used in the created note

### Code Changes

#### Before (Broken)
```python
# Normalize and extract properties
try:
    properties = normalize_properties(data)  # mp-slug gets filtered here!
    content = extract_content(properties)
    title = extract_title(properties)
    tags = extract_tags(properties)
    published_date = extract_published_date(properties)

    # Extract custom slug if provided (Micropub extension)
    custom_slug = None
    if 'mp-slug' in properties:  # BUG: mp-slug not in properties!
        slug_values = properties.get('mp-slug', [])
        if slug_values and len(slug_values) > 0:
            custom_slug = slug_values[0]
```

#### After (Fixed)
```python
# Extract mp-slug BEFORE normalizing properties (it's not a property!)
# mp-slug is a Micropub server extension parameter that gets filtered during normalization
custom_slug = None
if isinstance(data, dict) and 'mp-slug' in data:
    # Handle both form-encoded (list) and JSON (could be string or list)
    slug_value = data.get('mp-slug')
    if isinstance(slug_value, list) and slug_value:
        custom_slug = slug_value[0]
    elif isinstance(slug_value, str):
        custom_slug = slug_value

# Normalize and extract properties
try:
    properties = normalize_properties(data)
    content = extract_content(properties)
    title = extract_title(properties)
    tags = extract_tags(properties)
    published_date = extract_published_date(properties)
```

### Why This Fix Works

1. **Extracts before filtering**: Gets `mp-slug` from raw request data before `normalize_properties()` filters it out
2. **Handles both formats**:
   - Form-encoded: `mp-slug` is a list `["slug-value"]`
   - JSON: `mp-slug` can be string `"slug-value"` or list `["slug-value"]`
3. **Preserves existing flow**: The `custom_slug` variable was already being passed to `create_note()` correctly
4. **Architecturally correct**: Treats `mp-slug` as a server parameter (not a property), which aligns with Micropub spec

## Test Results

### Micropub Test Suite
All 13 Micropub tests passed:
```
tests/test_micropub.py::test_micropub_no_token PASSED
tests/test_micropub.py::test_micropub_invalid_token PASSED
tests/test_micropub.py::test_micropub_insufficient_scope PASSED
tests/test_micropub.py::test_micropub_create_note_form PASSED
tests/test_micropub.py::test_micropub_create_note_json PASSED
tests/test_micropub.py::test_micropub_create_with_name PASSED
tests/test_micropub.py::test_micropub_create_with_categories PASSED
tests/test_micropub.py::test_micropub_create_with_custom_slug_form PASSED  # NEW
tests/test_micropub.py::test_micropub_create_with_custom_slug_json PASSED  # NEW
tests/test_micropub.py::test_micropub_query_config PASSED
tests/test_micropub.py::test_micropub_query_source PASSED
tests/test_micropub.py::test_micropub_missing_content PASSED
tests/test_micropub.py::test_micropub_unsupported_action PASSED
```

### New Test Coverage

**Test 1: Form-encoded with custom slug**
- Request: `POST /micropub` with `content=...&mp-slug=my-custom-slug`
- Verifies: Location header ends with `/notes/my-custom-slug`
- Verifies: Note exists in database with correct slug

**Test 2: JSON with custom slug**
- Request: `POST /micropub` with JSON body including `"mp-slug": "json-custom-slug"`
- Verifies: Location header ends with `/notes/json-custom-slug`
- Verifies: Note exists in database with correct slug

### Regression Testing

All existing Micropub tests continue to pass, confirming:
- Authentication still works correctly
- Scope checking still works correctly
- Auto-generated slugs still work when no `mp-slug` provided
- Content extraction still works correctly
- Title and category handling still works correctly

## Validation Against Requirements

Per the architect's bug report (`docs/reports/custom-slug-bug-diagnosis.md`):

- [x] Extract `mp-slug` from raw request data
- [x] Extract BEFORE calling `normalize_properties()`
- [x] Handle both form-encoded (list) and JSON (string or list) formats
- [x] Pass `custom_slug` to `create_note()`
- [x] Add tests for both request formats
- [x] Ensure existing tests still pass

## Architecture Compliance

The fix maintains architectural correctness:

1. **Separation of Concerns**: `mp-slug` is correctly treated as a server extension parameter, not a Micropub property
2. **Existing Validation Pipeline**: The slug still goes through all validation in `create_note()`:
   - Reserved slug checking
   - Uniqueness checking with suffix generation if needed
   - Sanitization
3. **No Breaking Changes**: All existing functionality preserved
4. **Micropub Spec Compliance**: Aligns with how `mp-*` extensions should be handled

## Deployment Notes

### What to Test in Production

1. **Create note with custom slug via Quill**:
   - Use Quill client to create a note
   - Specify a custom slug in the slug field
   - Verify the created note uses your specified slug

2. **Create note without custom slug**:
   - Create a note without specifying a slug
   - Verify auto-generation still works

3. **Reserved slug handling**:
   - Try to create a note with slug "api" or "admin"
   - Should be rejected with validation error

4. **Duplicate slug handling**:
   - Create a note with slug "test-slug"
   - Try to create another with the same slug
   - Should get "test-slug-xxxx" with random suffix

### Known Issues

None. The fix is clean and complete.

### Version Impact

This fix will be included in **v1.1.0-rc.2** (or next release).

## Git Information

**Branch**: `bugfix/custom-slug-extraction`
**Commit**: 894e5e3
**Commit Message**: "fix: Extract mp-slug before property normalization"

**Files Changed**:
- `starpunk/micropub.py` (69 insertions, 8 deletions)
- `tests/test_micropub.py` (added 2 comprehensive tests)

## Next Steps

1. Merge `bugfix/custom-slug-extraction` into `main`
2. Deploy to production
3. Test with Quill client in production environment
4. Update CHANGELOG.md with fix details
5. Close any related issue tickets

## References

- **Bug Diagnosis**: `/home/phil/Projects/starpunk/docs/reports/custom-slug-bug-diagnosis.md`
- **Micropub Spec**: https://www.w3.org/TR/micropub/
- **Related ADR**: ADR-029 (Micropub Property Mapping)

## Conclusion

The custom slug feature is now fully functional. The bug was a simple timing issue in the extraction logic - trying to get `mp-slug` after it had been filtered out. The fix is clean, well-tested, and maintains all existing functionality while enabling the custom slug feature as originally designed.

The implementation follows the architect's design exactly and adds comprehensive test coverage for future regression prevention.