Sangeetha-Grantha

TRACK-099: Backend Compiler Warning Cleanup — Zero Warnings Target

Status: Completed

Progress Log

2026-03-17: Implemented all legacy code removals and DTO migrations to clear compiler warnings. Staged for commit.

Summary

Eliminate all 53 Kotlin compiler warnings across 9 backend files to achieve a zero-warning build. The vast majority (50/53) stem from TRACK-096 deprecated types that are still referenced by legacy scraping code. The remaining 3 are code quality issues.

Warning Inventory

By Deprecated Type (50 warnings)

Deprecated Type	Replacement	Count
`ScrapedKrithiMetadata`	`CanonicalExtractionDto`	20
`ScrapedSectionDto`	`CanonicalSectionDto`	14
`KrithiStructureParser`	Python `structure_parser.py`	7
`IWebScraper`	Remove (Python worker handles extraction)	4
`ScrapedLyricVariantDto`	`CanonicalLyricVariantDto`	3
`ScrapedTempleDetails`	`CanonicalExtractionDto` temple fields	2

Code Quality (3 warnings)

Warning	File	Line
Condition is always `true`	`ImportService.kt`	491
Condition is always `true`	`ImportService.kt`	517
Unnecessary safe call on non-null `String`	`ImportRoutes.kt`	186

By File (53 warnings)

File	Warnings	Category
`api/services/WebScrapingService.kt`	23	Legacy scraping — candidate for removal
`api/services/DeterministicWebScraper.kt`	11	Legacy scraping — candidate for removal
`api/services/LyricVariantPersistenceService.kt`	7	Active — migrate to Canonical DTOs
`api/services/ImportService.kt`	4	2 deprecated refs + 2 code quality
`api/services/scraping/StructuralVotingEngine.kt`	3	Legacy scraping — migrate to Canonical DTOs
`api/di/AppModule.kt`	2	Remove IWebScraper DI binding
`api/services/StructuralVotingProcessor.kt`	1	Migrate ScrapedSectionDto ref
`api/services/ScrapingPromptBuilder.kt`	1	Remove KrithiStructureParser import
`api/routes/ImportRoutes.kt`	1	Fix unnecessary safe call

Approach

Phase 1: Remove Dead Code (target: ~38 warnings)

Files that implement the legacy Kotlin scraping pipeline superseded by the Python extraction worker:

Delete or gut WebScrapingService.kt (23 warnings) — if no active callers remain
Delete or gut DeterministicWebScraper.kt (11 warnings) — if no active callers remain
Remove IWebScraper binding from AppModule.kt (2 warnings)
Remove KrithiStructureParser import from ScrapingPromptBuilder.kt (1 warning)
Remove KrithiStructureParser usage from LyricVariantPersistenceService.kt (1 warning — constructor call)

Phase 2: Migrate Active Code to Canonical DTOs (target: ~12 warnings)

Files that are actively used but still reference deprecated DTOs:

LyricVariantPersistenceService.kt — migrate ScrapedSectionDto → CanonicalSectionDto (6 remaining warnings)
ImportService.kt — migrate ScrapedKrithiMetadata → CanonicalExtractionDto (2 warnings)
StructuralVotingEngine.kt — migrate ScrapedSectionDto → CanonicalSectionDto (3 warnings)
StructuralVotingProcessor.kt — migrate ScrapedSectionDto → CanonicalSectionDto (1 warning)

Phase 3: Fix Code Quality (target: 3 warnings)

ImportService.kt:491,517 — remove redundant true conditions
ImportRoutes.kt:186 — remove unnecessary ?. safe call

Parallelization Strategy

Three parallel agents:

Agent 1 — Dead Code Removal: Phase 1 files (WebScrapingService, DeterministicWebScraper, AppModule, ScrapingPromptBuilder)
Agent 2 — DTO Migration: Phase 2 files (LyricVariantPersistenceService, ImportService, StructuralVotingEngine, StructuralVotingProcessor)
Agent 3 — Code Quality Fixes: Phase 3 files (ImportService, ImportRoutes)

Verification

# Must produce 0 lines of "w:" output
./gradlew :modules:backend:dal:clean :modules:backend:api:clean \
  :modules:backend:dal:compileKotlin :modules:backend:api:compileKotlin 2>&1 | grep "w:"

# All tests must pass
./gradlew :modules:backend:api:test

Dependencies

TRACK-096 (Payload Format Convergence) — this track completes the cleanup that TRACK-096 initiated by marking types as deprecated. Coordinate to avoid conflicts.

Risks

WebScrapingService and DeterministicWebScraper may still have active route callers — verify with usage analysis before deletion
DTO migration in LyricVariantPersistenceService touches critical lyric persistence logic — test thoroughly

Ref

Ref: application_documentation/02-architecture/tech-stack.md