detect-code-duplication

name	detect-code-duplication
description	Scan the GamesForMyKids codebase for repeated code patterns (game hooks, MenuScreen components, Zustand store slices, INITIAL_STATE objects, audio init) and open a GitHub issue for each meaningful duplication cluster found. Use when: detecting duplication, finding repeated code, refactoring candidates, DRY violations, extract shared logic, reduce copy-paste, open issues for code quality.
argument-hint	Optional: focus area (e.g. 'hooks', 'stores', 'menus', 'all')

Detect Code Duplication & Open GitHub Issues

When to Use

• Scanning for DRY violations before a refactoring sprint
• Periodic codebase health checks
• Before a PR that touches shared patterns
• When asked to "find duplicate code", "detect repeated patterns", "open refactoring issues"

Known Duplication Hotspots (as of April 2026)

Category	Pattern	Files affected	Priority
Game hooks	useXxxGame.ts — identical state shape + startGame + handleItemClick + audio init	app/games/*/use*Game.ts (~27 files)	High
MenuScreen components	Same emoji/title/description/score/button UI structure	app/games/*/components/*MenuScreen.tsx (~18 files)	High
Zustand store slices	createXxxSlice: StateCreator<...> = (set, get) => ({...})	app/games/*/store/slices/*Slice.ts, lib/stores/**/*Slice.ts (~16 files)	High
Store reset pattern	Every store: reset: () => set(INITIAL_STATE, false, 'ns/reset')	lib/stores/*.ts (~26 files)	Medium
INITIAL_STATE shape	{ score, level, isPlaying, showCelebration, ... } defined independently per game	app/games/*/use*Game.ts, lib/stores/*.ts (~20+ files)	Medium
Audio/speech init	initSpeechAndAudio(...) called identically in mount effect across game hooks	app/games/*/use*Game.ts	Medium

Procedure

Step 1 — Scope

If the user provided an argument, restrict the scan to that category. Otherwise scan all categories.

Step 2 — Scan Each Category

For each category run a targeted search and collect:

• Files affected (list paths)
• Duplicated lines / blocks (copy the smallest representative snippet)
• Count (how many times does this pattern appear?)
• Refactoring opportunity (what abstraction would fix it — base hook, shared component, factory, mixin?)

Use grep_search and semantic_search for broad sweeps, then read_file on representative files to verify the duplication is real.

2a. Game Hooks

grep_search: "useState.*isPlaying|useState.*showCelebration|startGame.*useCallback"
includePattern: "app/games/**/*.ts"

Confirm at least 3 files share the same state initialization shape.

2b. MenuScreen Components

file_search: "app/games/**/*MenuScreen.tsx"

Open 3 random results and compare imports, JSX shape, and prop interfaces.

2c. Zustand Slice Pattern

grep_search: "StateCreator<"
includePattern: "**/*Slice.ts"

Confirm the (set, get) => ({}) boilerplate repeats across ≥3 slices.

2d. Store Reset Pattern

grep_search: "reset: () => set(INITIAL_STATE"
includePattern: "lib/stores/*.ts"

Count occurrences.

2e. INITIAL_STATE Shape

grep_search: "const INITIAL_STATE|const INIT ="
isRegexp: true
includePattern: "**/*.ts"

List files that define nearly identical shapes.

2f. Audio Init Duplication

grep_search: "initSpeechAndAudio"

Count how many game hooks call this in an identical mount effect.

Step 3 — Evaluate Severity

Skip opening an issue if:

• Fewer than 3 files share the pattern
• The duplication is trivially small (1–2 lines) and not error-prone
• An issue for this pattern already exists (search GitHub first)

Open an issue if:

• ≥3 files share the pattern AND
• The duplication is ≥5 lines OR is a structural pattern (hook shape, component shape, store shape)

Step 4 — Search for Existing Issues

Before creating, search GitHub for duplicate issues:

Use: github-pull-request_doSearch
Query: "label:refactor OR label:code-quality <pattern-name>"

Step 5 — Open GitHub Issues

For each qualifying duplication cluster, create a GitHub issue using mcp_gitkraken_pull_request_create or github-pull-request_doSearch + mcp_gitkraken_issues_add_comment.

Issue template:

## Problem
<Pattern name> is duplicated across <N> files. Each file independently defines <description>.

## Affected Files
- `path/to/file1.ts`
- `path/to/file2.ts`
- `path/to/file3.ts`
(and N more — see grep results)

## Duplicated Pattern
\`\`\`typescript
// representative snippet (shortest form)
\`\`\`

## Proposed Solution
Extract to `<suggested path>` as a <base hook / shared component / factory function / mixin>.

Benefits: reduces maintenance surface, single source of truth for <behavior>.

## Effort estimate
- [ ] Small (< 1 day) — if pattern is pure extract with no logic change
- [ ] Medium (1–3 days) — if requires interface design + migration
- [ ] Large (> 3 days) — if touches >10 files or needs breaking change

Issue labels to apply: refactor, code-quality, tech-debt

Step 6 — Summary Report

After all issues are opened (or skipped), output a markdown table:

Pattern	Files	Issue	Action
Game hooks state shape	27	#XX	Opened
MenuScreen structure	18	#YY	Opened
...	...	...	Skipped (< 3 files)

References

• Known hotspot: game hooks — app/games/*/use*Game.ts
• Known hotspot: stores — lib/stores/*.ts
• Known hotspot: slices and app/games/*/store/slices/
• Existing shared abstractions — check here before proposing a new abstraction
• Base game hook — already exists for quiz games; check if similar exists for non-quiz games