fusion/coverage-report/gaps.md

Coverage Gap Analysis

Generated: 2026-04-01 Task: FN-689

Files Without Any Tests

Source files that have no corresponding test file (checked both co-located *.test.ts and __tests__/*.test.ts patterns).

Core Package (@fusion/core)

File	Lines	Category	Priority	Notes
agent-store.ts	597	Business Logic	High ✅	Agent state management store — covered by FN-704 (62 tests in agent-store.test.ts)
automation.ts	143	Types/Constants	Low	Pure type definitions and constant mappings — tested indirectly via automation-store.test.ts
mission-types.ts	253	Types/Constants	Low	Type definitions for missions — tested indirectly via mission-store.test.ts
types.ts	1228	Types/Constants	Low	Core type definitions — no runtime logic to test
index.ts	148	Barrel/Re-export	Low	Re-export barrel — no logic

Engine Package (@fusion/engine)

File	Lines	Category	Priority	Notes
ipc/ipc-host.ts	279	Infrastructure	High	IPC host for child process communication — critical for multi-project
ipc/ipc-worker.ts	325	Infrastructure	High	IPC worker for child process communication — critical for multi-project
runtimes/child-process-worker.ts	174	Infrastructure	Medium	Child process entry point — pairs with IPC worker
pi.ts	109	Integration	Medium	Pi integration utilities — external service integration
github.ts	37	Integration	Low	GitHub utility (small helper file)
index.ts	17	Barrel/Re-export	Low	Re-export barrel — no logic

CLI Package (@gsxdsm/fusion)

File	Lines	Category	Priority	Notes
bin.ts	786	Entry Point	High	Main CLI entry point with command registration — critical but integration-heavy
commands/backup.ts	131	Command	Medium	Backup CLI command — moderately important
commands/settings-export.ts	74	Command	Medium	Settings export command
commands/settings-import.ts	128	Command	Medium	Settings import command
runtime/native-patch.ts	223	Runtime	Medium	Native module patching — platform-specific logic

Dashboard Package (@fusion/dashboard)

Components Without Tests

File	Lines	Category	Priority	Notes
TaskChangesTab.tsx	199	UI Component	High	Task file changes display — user-facing feature
ProjectDetectionResults.tsx	253	UI Component	Medium	Project detection results display
SetupProjectForm.tsx	225	UI Component	Medium	Project setup form
SetupWizardModal.tsx	217	UI Component	Medium	First-run wizard modal
ProjectHealthBadge.tsx	106	UI Component	Medium	Project health status badge
FileBrowser.tsx	113	UI Component	Medium	File browser component
ProjectGridSkeleton.tsx	80	UI Component	Low	Loading skeleton — minimal logic
TaskCardBadge.tsx	69	UI Component	Low	Badge display component
WorktreeGroup.tsx	59	UI Component	Low	Worktree grouping component
StepTypeBadge.tsx	25	UI Component	Low	Simple badge — trivial
ToastContainer.tsx	18	UI Component	Low	Toast notifications container — trivial

Hooks Without Tests

File	Lines	Category	Priority	Notes
useProjectHealth.ts	143	Hook	High	Project health polling hook — multi-project feature
useFileEditor.ts	120	Hook	Medium	File editor hook (variants useProjectFileEditor/useWorkspaceFileEditor are tested)
useFileBrowser.ts	84	Hook	Medium	File browser hook (variants useProjectFileBrowser/useWorkspaceFileBrowser are tested)

Utils Without Tests

File	Lines	Category	Priority	Notes
projectDetection.ts	146	Utility	Medium	Project auto-detection logic

Server-Side (src/) Without Tests

File	Lines	Category	Priority	Notes
mission-routes.ts	1137	API Routes	High	Mission API route handlers — large untested file
terminal.ts	347	Service	High	Terminal service — complex functionality
subtask-breakdown.ts	331	Service	High	AI subtask breakdown service — user-facing feature
sse.ts	51	Service	Medium	Server-Sent Events utility
index.ts	5	Barrel/Re-export	Low	Re-export barrel

Entry Points (Not Testable)

File	Lines	Notes
app/main.tsx	10	React DOM entry point — bootstrap code
src/test-request.ts	95	Test utility, not production code

Summary by Priority

Priority	Count	Total Lines
High	10	4,143
Medium	15	2,693
Low	12	1,726

High-priority untested files represent the most critical coverage gaps:

1. dashboard/src/mission-routes.ts (1,137 lines) — Entire mission API surface untested
2. cli/src/bin.ts (786 lines) — CLI entry point with all command registration
3. core/src/agent-store.ts (597 lines) — Agent state management with zero coverage
4. dashboard/src/terminal.ts (347 lines) — Terminal service
5. dashboard/src/subtask-breakdown.ts (331 lines) — Subtask AI breakdown
6. engine/src/ipc/ipc-worker.ts (325 lines) — IPC worker
7. engine/src/ipc/ipc-host.ts (279 lines) — IPC host
8. dashboard/app/components/TaskChangesTab.tsx (199 lines) — File changes UI
9. dashboard/app/hooks/useProjectHealth.ts (143 lines) — Health polling hook
10. Engine tests cannot run with coverage due to OOM (pre-existing issue)

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Low Coverage Areas

Files that have tests but with coverage below thresholds: line coverage < 50%, function coverage < 50%, or branch coverage < 40%.

Note: Engine package numbers are from a partial coverage run (5 of 27 test files) due to OOM. Many engine files show 0% because their tests didn't run in the subset, not because of genuinely low coverage.

Package-Level Summary

Package	Files	Line Coverage	Function Coverage	Branch Coverage	Notes
core	21	80.6%	91.3%	84.4%	Good overall; agent-store.ts is the main gap
engine	30	6.0% ⚠️	77.8%	83.4%	Severely undercounted due to OOM — only 5/27 test files ran
cli	14	36.2%	44.3%	67.7%	Many commands lack tests; 8 of 18 test files failed
dashboard	108	70.2%	68.9%	84.6%	Good hooks/components; server-side routes need work

Core Package — Low Coverage Files

File	Lines %	Functions %	Branches %	Priority	Notes
gh-cli.ts	26.5%	20%	100%	Medium	GitHub CLI integration — 4 of 5 functions uncovered
ai-summarize.ts	59.5%	90.9%	81.8%	Low	Most logic covered, AI integration paths missing

The core package has strong overall coverage (80.6% lines). The main gap is agent-store.ts (0% — completely untested) and gh-cli.ts (26.5% — mostly untested integration code).

CLI Package — Low Coverage Files

File	Lines %	Functions %	Branches %	Priority	Notes
commands/task.ts	17.1%	40%	45.2%	High	Largest command file with most CLI functionality
project-resolver.ts	28.3%	33.3%	80.3%	High	Project resolution logic — critical for multi-project
commands/dashboard.ts	30.0%	9.1%	47.6%	Medium	Dashboard launch/management commands
extension.ts	56.3%	44.8%	70.7%	Medium	Pi extension — many tools have low function coverage
commands/project.ts	48.3%	50%	40.9%	Medium	Project management commands
project-context.ts	56.4%	60%	76.2%	Low	Project context resolution
commands/mission.ts	52.2%	55.6%	66.0%	Low	Mission CLI commands

Key finding: The commands/task.ts file (1,486 lines) has only 17% line coverage despite being the primary user-facing CLI surface. Many task subcommands are completely untested.

Dashboard Package — Low Coverage Files

Server-Side (API routes and services)

File	Lines %	Functions %	Branches %	Priority	Notes
server.ts	28.7%	40%	43.8%	High	Main server setup — much initialization untested
mission-routes.ts	37.0%	57.1%	84.9%	High	Mission API routes — large file, partial coverage
terminal.ts	36.6%	11.1%	100%	High	Terminal service — 8 of 9 functions untested
planning.ts	42.1%	63.3%	84.2%	Medium	AI planning service
routes.ts	47.1%	74.1%	92.7%	Medium	Main route handlers — many endpoints lack tests
subtask-breakdown.ts	50.6%	47.4%	50%	Medium	AI subtask service

Frontend Components

File	Lines %	Functions %	Branches %	Priority	Notes
NewTaskModal.tsx	47.1%	12.9%	56.6%	High	Complex modal with many untested interactions
SettingsModal.tsx	63.2%	39.7%	81.9%	Medium	Large settings modal — many sections untested
PlanningModeModal.tsx	82.0%	46.7%	80.7%	Low	Planning modal — some functions untested
SetupWizardModal.tsx	66.9%	25%	12.5%	Medium	Wizard modal — very low branch coverage
TaskCardBadge.tsx	38%	50%	100%	Low	Badge component — small file
WorktreeGroup.tsx	12.5%	0%	100%	Low	Worktree grouping — small file

Frontend Hooks

File	Lines %	Functions %	Branches %	Priority	Notes
useProjectHealth.ts	37.2%	100%	62.5%	Medium	Health hook — has function calls but low execution
useActivityLog.ts	74.4%	100%	92.3%	Low	Activity log hook

Engine Package — Known Coverage Data

⚠️ The engine package cannot run all tests with coverage enabled due to a pre-existing OOM issue. Tests consistently crash with "heap limit Allocation failed" even with --max-old-space-size=8192. The following is based on a partial run of 5 test files.

Files with confirmed good coverage (from partial run):

• concurrency.ts — 100% lines, 100% functions, 100% branches
• logger.ts — 100% lines, 100% functions, 100% branches
• agent-heartbeat.ts — 93.6% lines, 100% functions, 91.7% branches
• notifier.ts — 96.5% lines, 92.9% functions, 87.5% branches
• worktree-names.ts — 85.2% lines, 66.7% functions, 90.9% branches

Files that have tests but couldn't be measured (OOM prevented coverage collection):

• executor.ts (1,885 lines) — Core task executor
• merger.ts (1,275 lines) — Git merge logic
• scheduler.ts (611 lines) — Task scheduler
• triage.ts (1,205 lines) — Task specification
• reviewer.ts (344 lines) — Code/spec reviewer
• cron-runner.ts (407 lines) — Cron schedule runner
• worktree-pool.ts (215 lines) — Git worktree pool
• stuck-task-detector.ts (223 lines) — Stuck task detection
• pr-monitor.ts (298 lines) — PR monitoring
• pr-comment-handler.ts (190 lines) — PR comment handling

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Pre-Existing Test Failures

The following test failures were observed during coverage collection and are not caused by this task's changes:

Core Package (4 failures)

1. db-migrate.test.ts — 3 failures in legacy migration tests:

   • "migrates task.json files to tasks table" — expected undefined to be defined
   • "skips invalid task.json files" — expected undefined to be defined
   • "preserves all task fields through migration" — Cannot read properties of undefined
   • Root cause: Likely database schema drift — db.prepare().get() returns undefined

2. store.test.ts — 1 failure:

   • "adds log entry for the action" — comment log entry assertion fails
   • Root cause: addComment implementation may have changed log format

CLI Package (8 test files failed, 111 test failures)

• Multiple failures in task.test.ts, project.test.ts, dashboard.test.ts due to project resolution / TaskStore initialization errors
• Root cause: Tests depend on runtime initialization that may require additional mocking

Dashboard Package (select failures)

• Some component tests had intermittent failures related to mock setup
• SSE and websocket tests have timing-sensitive assertions

Engine Package

• All tests OOM when run together (with or without coverage)
• Individual test files pass when run in isolation
• Root cause: Memory leak in test infrastructure or test cleanup — pre-existing issue

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Top 10 Priority Files Needing Coverage Improvement

Ranked by combination of file size, criticality, and current coverage:

Rank	Package	File	Lines	Current Coverage	Why Critical
1	dashboard	src/mission-routes.ts	1,137	37% lines	Entire mission API — user-facing
2	cli	commands/task.ts	1,486	17% lines	Primary CLI interface — most used commands
3	core	agent-store.ts	597	0% lines	Agent state management — zero tests
4	dashboard	src/terminal.ts	347	37% lines	Terminal service — 8/9 functions untested
5	dashboard	src/server.ts	559	29% lines	Server initialization — critical path
6	engine	ipc/ipc-host.ts	279	0% (no test)	IPC host — multi-project critical
7	engine	ipc/ipc-worker.ts	325	0% (no test)	IPC worker — multi-project critical
8	cli	project-resolver.ts	915	28% lines	Project resolution — multi-project
9	dashboard	src/subtask-breakdown.ts	331	51% lines	AI subtask feature
10	dashboard	NewTaskModal.tsx	954	47% lines, 13% funcs	Complex modal — many untested paths