SubMiner/backlog/tasks/task-94 - Reduce-main.ts-to-thin-composition-root.md

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

id	title	status	assignee	created_date	updated_date	labels	dependencies	priority
TASK-94	Reduce main.ts to thin composition root	Done		2026-02-20 12:06	2026-02-21 04:12	architecture refactor maintainability	TASK-71 TASK-85	high

Description

src/main.ts still contains heavy deps-builder orchestration and high import concentration. Complete the composition-root refactor so main.ts owns boot wiring only and domain assembly moves behind registry/domain composer modules.

Action Steps

1. Baseline current main.ts fan-in (check:main-fanin, check:file-budgets, wc -l src/main.ts).
2. Introduce domain composer modules for repeated build-handler clusters (startup, overlay, jellyfin, anilist, ipc/shortcuts).
3. Move createBuild*MainDepsHandler call clusters out of main.ts into domain composer modules with narrow typed inputs.
4. Replace inline assembly in main.ts with single-call composer invocations per domain.
5. Add/adjust unit tests for new composer modules to lock shape and wiring.
6. Tighten check:main-fanin thresholds after refactor to prevent regression.
7. Re-run full config/core test gates and update TASK-71 progress.

Progress Notes

• 2026-02-21 baseline: src/main.ts = 3129 LOC; check:main-fanin = 105 import lines / 9 unique runtime paths.
• 2026-02-21 extraction slice: added composer modules src/main/runtime/composers/jellyfin-remote-composer.ts and src/main/runtime/composers/anilist-setup-composer.ts; moved corresponding createBuild*MainDepsHandler orchestration out of main.ts.
• 2026-02-21 tests: added focused composer shape tests at src/main/runtime/composers/jellyfin-remote-composer.test.ts and src/main/runtime/composers/anilist-setup-composer.test.ts.
• 2026-02-21 guardrail tighten: scripts/check-main-runtime-fanin.ts defaults tightened to import lines <= 110 and unique runtime paths <= 11.
• 2026-02-21 post-slice metrics: src/main.ts = 3042 LOC; check:main-fanin --strict = 103 import lines / 11 unique runtime paths.
• Remaining gap: startup/overlay/ipc/shortcuts composer extraction still required to fully meet thin composition-root target.

Acceptance Criteria

• #1 src/main.ts is composition-focused (boot/runtime wiring only; no broad deps-builder clusters).
• #2 Runtime import paths in src/main.ts stay domain-registry oriented (no relapse to per-leaf runtime imports).
• #3 check:main-fanin passes under updated threshold.
• #4 bun run test:core:dist passes with no CLI/IPC behavior regressions.

Implementation Plan

1. Extract IPC composition from src/main.ts into src/main/runtime/composers/ipc-runtime-composer.ts with focused tests (handler deps build, runtime handler creation, registration wiring).
2. Rewire src/main.ts IPC command and IPC registration blocks to consume the IPC composer while preserving existing helper wrappers and behavior.
3. Extract shortcuts composition from src/main.ts into src/main/runtime/composers/shortcuts-runtime-composer.ts with focused tests (global shortcuts runtime, numeric sessions, overlay shortcuts lifecycle).
4. Rewire src/main.ts shortcut runtime block to consume shortcuts composer while preserving downstream callsites.
5. Run targeted composer tests + check:main-fanin + test:core:dist; update TASK-94 notes with before/after metrics and finalize AC/status if all green.

Implementation Notes

2026-02-21: finished extraction pass by moving IPC command/registration, shortcuts runtime wiring, startup lifecycle wiring, and app-ready startup composition from src/main.ts into dedicated composer modules under src/main/runtime/composers/*.

Metrics: src/main.ts reduced from 3043 LOC to 2955 LOC in this pass; check:main-fanin import lines improved from 99 to 90 while remaining under enforced threshold.

Final Summary

Completed TASK-94 composition-root finish pass by extracting remaining large assembly clusters from src/main.ts into dedicated composer modules: IPC runtime (ipc-runtime-composer), shortcuts runtime (shortcuts-runtime-composer), startup lifecycle (startup-lifecycle-composer), and app-ready bootstrap (app-ready-composer). Main process behavior was preserved while reducing direct deps-builder orchestration in main.ts and keeping runtime wiring through domain/composer boundaries.

Added focused composer tests for each new module and reran project gates. Verification run: bun run build, bun test src/main/runtime/composers/ipc-runtime-composer.test.ts, bun test src/main/runtime/composers/shortcuts-runtime-composer.test.ts, bun test src/main/runtime/composers/startup-lifecycle-composer.test.ts, bun test src/main/runtime/composers/app-ready-composer.test.ts, bun run check:main-fanin, and bun run test:core:dist (all passing).

Definition of Done

• #1 src/main.ts LOC and fan-in metrics improve from pre-task baseline and are recorded in task notes.
• #2 New composer modules are covered by focused tests.
• #3 TASK-71 and TASK-85 progress notes reflect completed slice and remaining gap.