Sportstime/.planning/phases/08-dag-system-tdd/08-02-PLAN.md

phase, type

phase	type
08-dag-system-tdd	execute

TDD for GameDAGRouter performance with large datasets and diversity coverage.

Purpose: Ensure the DAG algorithm performs well with production-scale data (10K+ games) and produces diverse route options. Output: Performance test suite validating scalability and diversity guarantees, with code fixes if tests fail.

<execution_context> ~/.claude/get-shit-done/workflows/execute-phase.md ./summary.md ~/.claude/get-shit-done/references/tdd.md </execution_context>

@.planning/PROJECT.md @.planning/ROADMAP.md @SportsTime/Planning/Engine/GameDAGRouter.swift @SportsTimeTests/GameDAGRouterTests.swift Task 1: Add performance tests with large datasets SportsTimeTests/GameDAGRouterTests.swift Add performance tests to existing GameDAGRouterTests file.

Create helper to generate large test data:

private func generateLargeDataset(
    gameCount: Int,
    stadiumCount: Int,
    daysSpan: Int
) -> (games: [Game], stadiums: [UUID: Stadium])

Write RED tests:

1. 1000 games, 50 stadiums, 30 days → completes in <2 seconds
2. 5000 games, 100 stadiums, 60 days → completes in <10 seconds
3. 10000 games, 150 stadiums, 90 days → completes in <30 seconds
4. Memory: 10K games doesn't cause memory spike (verify routes returned, not OOM)

Use Swift Testing's Clock or ContinuousClock for timing:

@Test("10K games completes in reasonable time")
func performance_10KGames_CompletesInTime() async {
    let (games, stadiums) = generateLargeDataset(gameCount: 10000, stadiumCount: 150, daysSpan: 90)
    let start = ContinuousClock.now
    let routes = GameDAGRouter.findRoutes(games: games, stadiums: stadiums, constraints: .default)
    let elapsed = start.duration(to: .now)
    #expect(routes.count > 0, "Should return routes")
    #expect(elapsed < .seconds(30), "Should complete within 30 seconds")
}

Run tests and note any performance failures. Performance tests exist and execute 4 performance tests written with timing assertions

Task 2: Fix any performance issues SportsTime/Planning/Engine/GameDAGRouter.swift If performance tests fail (timeouts), optimize GameDAGRouter:

Potential optimizations (apply only if tests fail):

1. Reduce beam width for very large inputs (dynamic scaling based on game count)
2. Early termination when enough diverse routes found
3. More aggressive diversity pruning during expansion
4. Pre-compute stadium distances instead of recalculating

Do NOT weaken test expectations. If the test says 30 seconds, the code must meet that.

Re-run tests until performance requirements met.

xcodebuild -project SportsTime.xcodeproj -scheme SportsTime -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.2' -only-testing:SportsTimeTests/GameDAGRouterTests test

All performance tests pass within time limits All 4 performance tests pass within specified time limits

Task 3: Add diversity coverage tests SportsTimeTests/GameDAGRouterTests.swift Add tests verifying the diversity selection produces varied results:

1. Game count diversity: With 50 games over 10 days, routes include 2-game, 3-game, 4-game, and 5+ game options
2. City count diversity: Routes span different numbers of cities (2, 3, 4, 5+)
3. Mileage diversity: Routes include short (<500mi), medium (500-1000mi), and long (1000+mi) options
4. Duration diversity: Routes include 2-day, 3-day, 5-day, and 7+ day options
5. Bucket coverage: At least 3 of 5 game count buckets represented in output
6. No duplicates: All returned routes have unique game combinations

Test diversity by analyzing the returned routes:

@Test("diversity includes varied game counts")
func diversity_VariedGameCounts() {
    let (games, stadiums) = generateDiverseDataset() // 50 games, 20 stadiums, 14 days
    let routes = GameDAGRouter.findRoutes(games: games, stadiums: stadiums, constraints: .default)

    let gameCounts = Set(routes.map { $0.count })
    #expect(gameCounts.count >= 3, "Should have at least 3 different route lengths")
    #expect(gameCounts.contains { $0 <= 3 }, "Should include short routes")
    #expect(gameCounts.contains { $0 >= 5 }, "Should include long routes")
}

```bash xcodebuild -project SportsTime.xcodeproj -scheme SportsTime -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.2' -only-testing:SportsTimeTests/GameDAGRouterTests test ``` All diversity tests pass 6 diversity tests pass, verifying multi-dimensional variety Task 4: Fix any diversity issues SportsTime/Planning/Engine/GameDAGRouter.swift If diversity tests fail, fix selectDiverseRoutes() logic:

Common issues:

1. Not all buckets being sampled (check pass 1-4 in selectDiverseRoutes)
2. Short routes getting pruned too early (check diversityPrune)
3. Bucket calculations wrong (check RouteProfile bucket properties)

Fix the diversity algorithm to ensure varied output. Do NOT modify test expectations.

xcodebuild -project SportsTime.xcodeproj -scheme SportsTime -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.2' -only-testing:SportsTimeTests/GameDAGRouterTests test

All tests pass All diversity tests pass, proving multi-dimensional route variety

Before declaring phase complete: - [ ] Performance tests pass for 1K, 5K, 10K game datasets - [ ] Diversity tests verify varied route lengths, cities, miles, durations - [ ] No test assertions weakened to pass - [ ] All existing GameDAGRouter edge case tests still pass - [ ] Full test suite runs successfully

<success_criteria>

• All tasks completed
• All verification checks pass
• 10+ new tests (4 performance + 6 diversity)
• GameDAGRouter handles 10K+ games efficiently
• Diversity selection produces varied results </success_criteria>

After completion, create `.planning/phases/08-dag-system-tdd/08-02-SUMMARY.md`