SubMiner/backlog/tasks/task-5 - Eliminate-type-duplication-between-renderer.ts-and-types.ts.md

id, title, status, assignee, created_date, updated_date, labels, milestone, dependencies, references, priority

id	title	status	assignee	created_date	updated_date	labels	milestone	dependencies	references	priority
TASK-5	Eliminate type duplication between renderer.ts and types.ts	Done	codex	2026-02-11 08:20	2026-02-11 17:46	refactor types renderer	Codebase Clarity & Composability		src/renderer/renderer.ts src/types.ts src/main.ts	high

Description

renderer.ts locally redefines 20+ interfaces/types that already exist in types.ts: MergedToken, SubtitleData, MpvSubtitleRenderMetrics, Keybinding, SubtitlePosition, SecondarySubMode, all Jimaku/Kiku types, RuntimeOption types, SubsyncSourceTrack, SubsyncManualPayload, etc.

This creates divergence risk — changes in types.ts don't automatically propagate to the renderer's local copies.

Additionally, DEFAULT_MPV_SUBTITLE_RENDER_METRICS and sanitizeMpvSubtitleRenderMetrics() exist only in renderer.ts despite being shared concerns (main.ts also has DEFAULT_MPV_SUBTITLE_RENDER_METRICS).

Acceptance Criteria

• #1 All shared types are imported from types.ts — no local redefinitions in renderer.ts
• #2 DEFAULT_MPV_SUBTITLE_RENDER_METRICS lives in one canonical location (types.ts or a shared module)
• #3 sanitizeMpvSubtitleRenderMetrics moved to a shared module importable by both main and renderer
• #4 TypeScript compiles cleanly with no type errors
• #5 Renderer-only types (ChordAction, KikuModalStep, KikuPreviewMode) can stay local

Implementation Plan

1. Audit src/renderer/renderer.ts, src/types.ts, and src/main.ts to identify every duplicated type and both subtitle-metrics helpers/constants.
2. Remove duplicated shared type declarations from renderer.ts and replace them with direct imports from types.ts; keep renderer-only types (ChordAction, KikuModalStep, KikuPreviewMode) local.
3. Create a single canonical home for DEFAULT_MPV_SUBTITLE_RENDER_METRICS in a shared location and update all call sites to import it from that canonical module.
4. Move sanitizeMpvSubtitleRenderMetrics to a shared module importable by both main and renderer, then switch both files to consume that shared implementation.
5. Run TypeScript compile/check, fix any fallout, and verify no local shared-type redefinitions remain in renderer.ts.
6. Update task notes and check off acceptance criteria as each item is validated.

Implementation Notes

Replaced renderer-local shared type declarations with import type from src/types.ts; only KikuModalStep, KikuPreviewMode, and ChordAction remain local in renderer.

Moved canonical MPV subtitle metrics defaults to src/core/services/mpv-render-metrics-service.ts as DEFAULT_MPV_SUBTITLE_RENDER_METRICS and switched main.ts to consume it.

Added shared sanitizeMpvSubtitleRenderMetrics export in src/core/services/mpv-render-metrics-service.ts and re-exported it from src/core/services/index.ts.

Removed renderer-local DEFAULT_MPV_SUBTITLE_RENDER_METRICS, coerceFiniteNumber, and sanitizeMpvSubtitleRenderMetrics; renderer now consumes full sanitized metrics from main via IPC and keeps nullable local state until startup metrics are loaded.

Validation: pnpm run build passed; node --test dist/core/services/mpv-render-metrics-service.test.js passed.

Final Summary

Implemented TASK-5 by eliminating duplicate shared type/model definitions from the renderer and centralizing MPV subtitle render metrics primitives.

What changed:

• src/renderer/renderer.ts
  • Removed local redefinitions of shared interfaces/types (subtitle, keybinding, Jimaku, Kiku, runtime options, subsync, render metrics).
  • Added import type usage from src/types.ts for shared contracts.
  • Kept renderer-only local types (KikuModalStep, KikuPreviewMode, ChordAction).
  • Removed renderer-local metrics default/sanitization helpers and switched invisible overlay resize behavior to rely on already-synced metrics state from main.
• src/core/services/mpv-render-metrics-service.ts
  • Added canonical DEFAULT_MPV_SUBTITLE_RENDER_METRICS export.
  • Added shared sanitizeMpvSubtitleRenderMetrics export.
• src/core/services/index.ts
  • Re-exported DEFAULT_MPV_SUBTITLE_RENDER_METRICS and sanitizeMpvSubtitleRenderMetrics.
• src/main.ts
  • Removed local default metrics constant and imported the canonical default from core services.
• src/core/services/mpv-render-metrics-service.test.ts
  • Updated base fixture to derive from canonical default metrics constant.

Why:

• Prevent type drift between renderer and shared contracts.
• Establish a single source of truth for MPV subtitle render metric defaults and sanitization utilities.

Validation:

• pnpm run build
• node --test dist/core/services/mpv-render-metrics-service.test.js

Result:

• Shared renderer types now come from types.ts.
• MPV subtitle render metrics defaults are canonicalized in one shared module.
• TypeScript compiles cleanly and relevant metrics service tests pass.