SubMiner/backlog/tasks/task-95 - Decompose-remaining-oversized-core-hotspots.md

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

id	title	status	assignee	created_date	updated_date	labels	dependencies	references	priority
TASK-95	Decompose remaining oversized core hotspots	Done	codex-task95-hotspots	2026-02-20 12:06	2026-02-21 03:29	architecture refactor maintainability	TASK-85	docs/plans/2026-02-21-task-95-hotspot-decomposition-plan.md	high

Description

Three core files remain materially oversized and unfinished: src/anki-integration.ts, src/config/service.ts, and src/core/services/immersion-tracker-service.ts. Complete decomposition into focused collaborators/modules with behavior preserved and regression coverage.

Action Steps

1. Capture per-file baseline LOC and key responsibilities (constructor orchestration, phase lifecycle, persistence/sync/event flow).
2. For src/anki-integration.ts: extract facade collaborators by domain (config/field resolution/media/card creation/notifications) and reduce class surface to orchestration.
3. For src/config/service.ts: split lifecycle phases into explicit modules (load, migrate, validate, warnings) and keep API stable.
4. For src/core/services/immersion-tracker-service.ts: separate state/reducer, persistence adapter, and sync/reporting orchestration.
5. Add focused tests for extracted modules and preserve existing integration-level assertions.
6. Run full build + config/core tests + file-budget checks; record before/after LOC metrics.
7. Update TASK-85 AC/DoD linkage to mark completed sub-scope with evidence.

Acceptance Criteria

• #1 src/anki-integration.ts, src/config/service.ts, and src/core/services/immersion-tracker-service.ts are each reduced with clear collaborator boundaries.
• #2 Public behavior remains unchanged (existing config/core tests pass).
• #3 New seam tests cover extracted collaborators/modules.
• #4 File-budget report reflects measurable LOC reduction on all three hotspots.

Implementation Plan

Execution plan of record: docs/plans/2026-02-21-task-95-hotspot-decomposition-plan.md

1. Capture baseline LOC and file-budget status for the 3 hotspot files.
2. Add characterization seam tests before extraction in each domain (Anki, Config, Immersion).
3. Decompose each hotspot behind stable facades by extracting focused collaborators/modules.
4. Use parallel subagents for independent hotspot workstreams; integrate safely on shared boundaries.
5. Run required gates (bun run build, bun run test:config:dist, bun run test:core:dist, bun run check:file-budgets).
6. Record before/after LOC plus ownership map; update TASK-95 AC/DoD and TASK-85 progress evidence.

Implementation Notes

Baseline LOC (before): src/anki-integration.ts 1722, src/config/service.ts 1591, src/core/services/immersion-tracker-service.ts 1470.

After LOC: src/anki-integration.ts 1315 (-407), src/config/service.ts 99 (-1492), src/core/services/immersion-tracker-service.ts 1109 (-361).

Module ownership map: Anki -> src/anki-integration/field-grouping-merge.ts; Config -> src/config/{load.ts,parse.ts,warnings.ts,resolve.ts}; Immersion -> src/core/services/immersion-tracker/{types.ts,reducer.ts,queue.ts,maintenance.ts,query.ts}.

Seam tests added: src/anki-integration.test.ts (field-grouping merge seams), src/config/config.test.ts (loader/strict reload/warning determinism seams), src/core/services/immersion-tracker-service.test.ts (queue/reducer/month-key seams).

Verification gates passed: bun run build, bun run test:config:dist (43 pass), bun run test:core:dist (204 pass, 10 skipped, 0 fail), bun run check:file-budgets (warning-mode report with all three hotspot LOC reduced).

Definition of Done

• #1 Refactor notes include before/after LOC and module ownership map for all three files.
• #2 bun run build, bun run test:config:dist, bun run test:core:dist pass.
• #3 TASK-85 progress/AC reflects this completion slice with evidence links.