[LNK-67] global common 코틀린 마이그레이션

.claude/agents/kotlin-migration-agent.md

@@ -14,11 +14,81 @@ Migrate Java to idiomatic Kotlin with Test-First methodology.
 
 ### 1. Pre-Migration Test
 - Analyze Java code behavior and dependencies
-- Write tests FIRST in `src/test/kotlin/{domain}/`
+- **Write ONLY essential tests** that verify critical business logic
 - Use Kotest + mockk
 - Run tests against Java code to confirm they pass
 
+**Tests to Write (HIGH value):**
+- Business logic with conditions/branching (예: 권한 검증, 상태 체크, 조건부 로직)
+- Exception scenarios (예: 존재하지 않는 엔티티 조회 시 예외, 권한 없음 예외)
+- Complex calculations or transformations
+- Transaction boundaries and side effects
+- Custom query methods with specific logic
+- Domain validation rules
+
+**Tests to SKIP (LOW value):**
+- JPA basic CRUD (findById, save, delete, findAll)
+- Simple getter/setter or DTO field mapping
+- Obvious pass-through methods (repository calls without logic)
+- Framework-provided functionality
+- Constructor assignments
+- Simple delegation patterns
+
+**Example - Service to Test:**
+```java
+public Feed getFeed(Long feedId, Long userId) {
+    Feed feed = feedRepository.findById(feedId)
+        .orElseThrow(() -> new FeedNotFoundException());
+
+    if (feed.isBlocked(userId)) {  // ← Test this
+        throw new FeedAccessDeniedException();  // ← Test this
+    }
+
+    return feed;  // ← Don't test simple return
+}
+```
+
+**Write 2-3 focused tests:**
+- "존재하지 않는 피드 조회 시 예외 발생"
+- "차단된 사용자가 조회 시 예외 발생"
+- (Optional) "정상 피드 조회 시 반환" only if complex setup is needed
+
+**Skip if code is trivial:**
+```java
+public void deleteFeed(Long feedId) {
+    feedRepository.deleteById(feedId);  // ← Skip, JPA basic method
+}
+```
+
 ### 2. Migration
+
+#### File Move and Conversion Workflow
+**Instead of deleting Java files and creating new ones, move files using `git mv` then modify the content.**
+
+**Step 1: Move file path**
+```bash
+git mv src/main/java/leets/leenk/domain/{domain}/{path}/{File}.java \
+       src/main/kotlin/leets/leenk/domain/{domain}/{path}/{File}.kt
+```
+
+**Step 2: Convert to Kotlin**
+- Read current file using Read tool
+- Modify file content from Java → Kotlin syntax using Edit tool
+- Keep business logic identical
+
+**Step 3: Run tests**
+```bash
+./gradlew test  # Run pre-written tests
+```
+
+**Benefits:**
+- `git log --stat` clearly shows file move + modifications
+- `git show` can verify actual code changes
+- `git blame` can track commit history of Java version
+
+---
+
+#### Migration Guide
 - Convert to Kotlin preserving architecture: Controller → UseCase → Domain Service → Repository
 - Apply Kotlin idioms: data class for DTOs, val over var, nullable only when needed
 - Keep Single Responsibility: `{Domain}GetService`, `{Domain}SaveService`, etc.

.claude/commands/code-review.md

@@ -0,0 +1,34 @@
+---
+description: "코드 리뷰 에이전트를 활용해 현재까지의 작업을 리뷰합니다."
+---
+
+# Code Review Command
+
+Invoke the code review agent defined in `.claude/agents/code-review-agent.md` to perform code review.
+
+## Determine Review Target
+
+1. Check staged changes with `git diff --staged`
+2. If nothing staged, check current branch commit history with `git log` and review
+
+## Rules
+
+- If agent file (`.claude/agents/code-review-agent.md`) doesn't exist, notify user and stop
+- Follow the checklist and output format defined in the agent exactly
+
+
+## Changes
+
+| Item | Reason |
+|------|--------|
+| Specify agent path | Claude needs exact file location to find it |
+| Specific git commands | Clear instructions on how to check |
+| Add "follow agent format" | Prevent ignoring agent file's output format |
+
+## Folder Structure
+
+.claude/
+├── commands/
+│   └── code-review.md      # This command file
+└── agents/
+    └── code-review-agent.md  # Agent definition (checklist, output format, etc.)

.claude/commands/kotlin-migrate.md

@@ -0,0 +1,42 @@
+---
+description: "kotlin-migration-agent를 사용해 Java 파일을 코틀린으로 마이그레이션하는 명령어입니다."
+---
+
+# Instructions
+
+You MUST use the Task tool to invoke the kotlin-migration-agent immediately.
+
+## Input Processing
+
+1. If user provides a file path:
+   - Use Read tool to verify the file exists and is a Java file
+   - Pass the absolute file path to the agent
+
+2. If user provides a directory path:
+   - Use Glob to find all `.java` files in that directory
+   - Pass the directory path to the agent
+
+3. If no path provided:
+   - Ask user to specify the Java file or directory to migrate
+
+## Agent Invocation
+
+Call the Task tool with:
+- subagent_type: "kotlin-migration-agent"
+- prompt: "Migrate [FILE_PATH or DIRECTORY_PATH] from Java to Kotlin following the Test-First methodology"
+- description: "Migrate Java to Kotlin"
+
+Example:
+```text
+Task tool:
+  subagent_type: kotlin-migration-agent
+  prompt: Migrate src/main/java/leets/leenk/domain/feed/service/FeedGetService.java from Java to Kotlin following the Test-First methodology
+  description: Migrate Java to Kotlin
+```
+
+## Important Notes
+
+- NEVER perform migration yourself - ALWAYS delegate to kotlin-migration-agent
+- Agent will handle: test writing, migration, refactoring, and ktlint verification
+- Agent follows strict order: Test → Migrate → Refactor → Verify
+- All agent output will be in Korean as per agent rules

CLAUDE.md

@@ -88,12 +88,17 @@ refactor: dto validation 수정
 ## Testing
 
 - **Kotest** + **MockK** for unit tests
+- **springmockk** for Spring bean mocking - use `@MockkBean` instead of `@MockBean`
 - **Testcontainers** for integration tests (MySQL, MongoDB)
 - Test both success and failure scenarios
-- Use `@DisplayName` for clear test descriptions
+- **Kotest Test Styles:**
+  - `StringSpec` - Simple tests with minimal boilerplate
+  - `BehaviorSpec` - BDD-style tests (Given/When/Then)
+  - `DescribeSpec` - Technical specs requiring detailed structure and readability
+- Controller tests: Use `@WebMvcTest` with `@Import` for Security config testing
 
 ## Notes
 
 - Swagger UI: `/swagger-ui.html`
 - Profiles: `local` (default), `dev`
-- Auth: OAuth2 Resource Server with JWT (Apple via Kakao)
+- Auth: OAuth2 Resource Server with JWT (Apple via Kakao)

build.gradle.kts

@@ -60,6 +60,7 @@ dependencies {
     testImplementation("org.testcontainers:mysql")
     testImplementation("org.testcontainers:mongodb")
     testImplementation("io.mockk:mockk:1.14.7")
+    testImplementation("com.ninja-squad:springmockk:4.0.2")
     testImplementation("org.jetbrains.kotlin:kotlin-test-junit5")
 
     // Kotest