StarPunk/docs/design/v1.5.0/2025-12-17-phase-1-implementation-report.md

Phase 1 Implementation Report: Timestamp-Based Slugs

Date: 2025-12-17 Developer: StarPunk Fullstack Developer Agent Phase: v1.5.0 Phase 1 - Timestamp-Based Slugs Status: ✅ Complete

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Summary

Implemented timestamp-based slug generation per ADR-062, replacing the content-based slug algorithm with a simpler, privacy-preserving timestamp format. All tests pass (892 total).

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Changes Implemented

1. New Function: generate_timestamp_slug()

File: /home/phil/Projects/starpunk/starpunk/slug_utils.py

Created new function that generates slugs in YYYYMMDDHHMMSS format with sequential collision handling:

def generate_timestamp_slug(
    created_at: datetime = None,
    existing_slugs: Set[str] = None
) -> str:
    """Generate a timestamp-based slug with collision handling.

    Per ADR-062: Default format is YYYYMMDDHHMMSS with sequential
    suffix (-1, -2, etc.) for collisions.
    """

Key Features:

• Base format: 20251216143052 (14 characters)
• First collision: 20251216143052-1
• Second collision: 20251216143052-2
• Defaults to UTC now if no timestamp provided
• Handles empty existing_slugs set gracefully

2. Updated Note Creation

File: /home/phil/Projects/starpunk/starpunk/notes.py (lines 228-231)

Before:

else:
    # Generate base slug from content
    base_slug = generate_slug(content, created_at)

    # Make unique if collision
    slug = make_slug_unique(base_slug, existing_slugs)

    # Validate final slug (defensive check)
    if not validate_slug(slug):
        raise InvalidNoteDataError("slug", slug, f"Generated slug is invalid: {slug}")

After:

else:
    # Generate timestamp-based slug (ADR-062)
    from starpunk.slug_utils import generate_timestamp_slug
    slug = generate_timestamp_slug(created_at, existing_slugs)

Simplification: Removed 8 lines of code, including:

• Content-based slug generation call
• Separate uniqueness check
• Defensive validation check (timestamp slugs are valid by construction)

3. Updated Tests

Added: tests/test_timestamp_slugs.py

New comprehensive test file with 18 tests covering:

• Basic timestamp format validation
• Collision handling with sequential suffixes
• Edge cases (midnight, end of day, leap year, single-digit padding)
• Integration with note creation
• Custom slug compatibility verification

Updated: tests/test_custom_slugs.py

• Added TIMESTAMP_SLUG_PATTERN constant for validation
• Updated test_create_note_without_custom_slug to use pattern matching
• Updated test_empty_slug_uses_auto_generation to verify timestamp format
• Updated test_whitespace_only_slug_uses_auto_generation to accept both old and new timestamp formats

Note: Whitespace custom slugs go through sanitize_slug() which uses the older YYYYMMDD-HHMMSS format. This is acceptable as it only affects invalid custom slugs, not default generation.

Updated: tests/test_notes.py

• Updated test_create_generates_unique_slug to test timestamp collision handling with fixed timestamps

4. Preserved Legacy Code

File: /home/phil/Projects/starpunk/starpunk/utils.py

The old generate_slug() function remains unchanged for backward compatibility and potential future use. This follows the architect's guidance in the response document.

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Testing Results

Test Summary

892 passed, 1 warning in ~6 minutes

Test Count Change:

• Previous: 874 tests
• New: 892 tests (+18 from new test_timestamp_slugs.py file)

Key Tests Verified

1. Timestamp Format:

   • ✅ Format matches YYYYMMDDHHMMSS exactly
   • ✅ No hyphen between date and time components
   • ✅ 14 characters total

2. Collision Handling:

   • ✅ Base slug gets no suffix: 20251216143052
   • ✅ First collision gets -1: 20251216143052-1
   • ✅ Second collision gets -2: 20251216143052-2
   • ✅ Sequential suffixes work up to 10+

3. Edge Cases:

   • ✅ Midnight timestamp: 20250101000000
   • ✅ End of day: 20251231235959
   • ✅ Leap year: 20240229123045
   • ✅ Single-digit padding: 20250105090503

4. Integration:

   • ✅ Creating note without custom slug generates timestamp
   • ✅ Multiple notes at same second get sequential suffixes
   • ✅ Custom slugs via mp-slug still work unchanged
   • ✅ Web UI custom slug field still works

5. Compatibility:

   • ✅ No collision with reserved slugs (timestamp = numeric, reserved = alphabetic)
   • ✅ Existing notes unaffected (no migration needed)

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Acceptance Criteria

Per docs/projectplan/v1.5.0/RELEASE.md Phase 1:

• ✅ Default slugs use YYYYMMDDHHMMSS format
• ✅ Collision handling uses -1, -2 suffix (sequential)
• ✅ Custom slugs via mp-slug work unchanged
• ✅ Custom slugs via web UI work unchanged
• ✅ Existing notes unaffected
• ✅ ADR-062 referenced in code comments (in function docstring)

All acceptance criteria met.

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Code Quality

Lines of Code Impact

• Added: 47 lines (new function + docstring)
• Removed: 8 lines (simplified note creation logic)
• Net: +39 lines in production code
• Tests: +200 lines (comprehensive new test file)

Complexity Reduction

• Removed content extraction logic
• Removed word normalization
• Removed multiple fallback paths
• Removed defensive validation check
• Simplified collision handling (sequential vs random)

Maintainability

• Single responsibility: timestamp generation
• Clear, predictable behavior
• No edge cases for content (unicode, short text, special chars)
• Easier to debug (no randomness in collision handling)

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Privacy & Security

Privacy Improvements

• ✅ Note content no longer visible in URLs
• ✅ Timestamps reveal only creation time, not content
• ✅ No accidental information leakage through slugs

Security Considerations

• ✅ Timestamp slugs cannot collide with reserved slugs (different character sets)
• ✅ Sequential suffixes are deterministic but not a security concern
• ✅ No user-controlled input in default slug generation

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Performance

Generation Speed

• Before: Extract words → normalize → check uniqueness → add random suffix
• After: Format timestamp → check uniqueness → add sequential suffix

Improvement: Timestamp formatting is O(1) vs content parsing which is O(n) where n = content length.

Database Queries

• No change (uniqueness check still requires one query)

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Documentation References

All implementation decisions based on:

• docs/decisions/ADR-062-timestamp-based-slug-format.md
• docs/design/v1.5.0/2025-12-16-architect-responses.md
• docs/projectplan/v1.5.0/RELEASE.md

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Known Limitations

Two Timestamp Formats in System

The system now has two timestamp formats:

1. Default slugs: YYYYMMDDHHMMSS (ADR-062, no hyphen)
2. Custom slug fallback: YYYYMMDD-HHMMSS (old format, with hyphen)

This occurs when:

• User provides custom slug that fails normalization (e.g., emoji, whitespace)
• System falls back to timestamp via sanitize_slug()

Impact: Minimal. Both formats are valid, sortable, and private. The difference only affects edge cases of invalid custom slugs.

Future Consideration: Could unify formats in v1.6.0 by updating sanitize_slug() to use new format.

No Reserved Slug Check for Timestamp Slugs

Per architect's decision (Q4 in responses), timestamp slugs skip reserved slug validation because:

• Timestamp slugs are purely numeric
• Reserved slugs are alphabetic
• Collision is impossible by construction

This is a simplification, not a limitation.

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Migration Notes

Existing Data

• No database migration required
• Existing notes keep their content-based slugs
• All existing URLs remain valid
• Old and new slug formats coexist naturally

Rollback Plan

If rollback is needed:

1. Revert changes to notes.py (restore old logic)
2. Remove generate_timestamp_slug() function
3. Remove test_timestamp_slugs.py file
4. Restore old test assertions

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Next Steps

Per task instructions:

1. ✅ Create this implementation report
2. ⏳ Commit changes (pending)
3. ⏳ Report back to architect for review
4. ⏸️ Do NOT proceed to Phase 2 until review complete

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Files Changed

Production Code

1. /home/phil/Projects/starpunk/starpunk/slug_utils.py - Added generate_timestamp_slug()
2. /home/phil/Projects/starpunk/starpunk/notes.py - Updated default slug generation

Tests

1. /home/phil/Projects/starpunk/tests/test_timestamp_slugs.py - New file (18 tests)
2. /home/phil/Projects/starpunk/tests/test_custom_slugs.py - Updated 4 tests
3. /home/phil/Projects/starpunk/tests/test_notes.py - Updated 1 test

Documentation

1. /home/phil/Projects/starpunk/docs/design/v1.5.0/2025-12-17-phase-1-implementation-report.md - This file

Total files modified: 6

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Developer Notes

What Went Well

• Clear specifications in ADR-062 and architect responses
• Sequential suffix logic is simpler than random suffix
• Pattern matching in tests makes assertions flexible
• Implementation was straightforward with no surprises

Challenges Encountered

1. Test import error: Used starpunk.db instead of starpunk.database (fixed)
2. Two timestamp formats: Discovered old format in sanitize_slug() (documented)
3. Test runtime: Full suite takes ~6 minutes (acceptable for CI)

Code Review Points

• Verify timestamp format consistency is acceptable
• Confirm sequential suffix behavior meets requirements
• Check if generate_slug() in utils.py should be deprecated
• Consider future unification of timestamp formats

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Implementation Status: ✅ Ready for Architect Review