Merge pull request #309 from cookiee339/feat/kotlin-ecosystem

feat(kotlin): add Kotlin/Ktor/Exposed ecosystem
2026-03-30 13:43:26 +08:00 · 2026-03-13 00:01:06 -07:00
parent 3010f75297 99d443b16e
commit 4de5da2f8f
14 changed files with 3905 additions and 0 deletions
--- a/commands/kotlin-build.md
+++ b/commands/kotlin-build.md
@@ -0,0 +1,174 @@
+---
+description: Fix Kotlin/Gradle build errors, compiler warnings, and dependency issues incrementally. Invokes the kotlin-build-resolver agent for minimal, surgical fixes.
+---
+
+# Kotlin Build and Fix
+
+This command invokes the **kotlin-build-resolver** agent to incrementally fix Kotlin build errors with minimal changes.
+
+## What This Command Does
+
+1. **Run Diagnostics**: Execute `./gradlew build`, `detekt`, `ktlintCheck`
+2. **Parse Errors**: Group by file and sort by severity
+3. **Fix Incrementally**: One error at a time
+4. **Verify Each Fix**: Re-run build after each change
+5. **Report Summary**: Show what was fixed and what remains
+
+## When to Use
+
+Use `/kotlin-build` when:
+- `./gradlew build` fails with errors
+- Kotlin compiler reports errors
+- `./gradlew detekt` reports violations
+- Gradle dependency resolution fails
+- After pulling changes that break the build
+
+## Diagnostic Commands Run
+
+```bash
+# Primary build check
+./gradlew build 2>&1
+
+# Static analysis
+./gradlew detekt 2>&1 || echo "detekt not configured"
+./gradlew ktlintCheck 2>&1 || echo "ktlint not configured"
+
+# Dependency issues
+./gradlew dependencies --configuration runtimeClasspath 2>&1 | head -100
+
+# Optional deep refresh when caches or dependency metadata are suspect
+./gradlew build --refresh-dependencies
+```
+
+## Example Session
+
+````text
+User: /kotlin-build
+
+Agent:
+# Kotlin Build Resolution
+
+## Initial Diagnostics
+
+```bash
+$ ./gradlew build
+e: src/main/kotlin/com/example/service/UserService.kt:25:15 Unresolved reference: UserRepository
+e: src/main/kotlin/com/example/routes/UserRoutes.kt:42:9 Type mismatch: inferred type is String but Int was expected
+e: src/main/kotlin/com/example/routes/UserRoutes.kt:58:5 'when' expression must be exhaustive
+```
+
+Errors found: 3
+
+## Fix 1: Unresolved Reference
+
+File: src/main/kotlin/com/example/service/UserService.kt:25
+Error: Unresolved reference: UserRepository
+Cause: Missing import
+
+```kotlin
+// Added import
+import com.example.repository.UserRepository
+```
+
+```bash
+$ ./gradlew build
+# 2 errors remaining
+```
+
+## Fix 2: Type Mismatch
+
+File: src/main/kotlin/com/example/routes/UserRoutes.kt:42
+Error: Type mismatch: inferred type is String but Int was expected
+
+```kotlin
+// Changed
+val count = call.parameters["count"]
+// To
+val count = call.parameters["count"]?.toIntOrNull()
+    ?: return@get call.respond(HttpStatusCode.BadRequest, "Invalid count")
+```
+
+```bash
+$ ./gradlew build
+# 1 error remaining
+```
+
+## Fix 3: Non-Exhaustive When
+
+File: src/main/kotlin/com/example/routes/UserRoutes.kt:58
+Error: 'when' expression must be exhaustive
+
+```kotlin
+// Added missing branch
+when (user.role) {
+    Role.ADMIN -> handleAdmin(user)
+    Role.USER -> handleUser(user)
+    Role.MODERATOR -> handleModerator(user) // Added
+}
+```
+
+```bash
+$ ./gradlew build
+# Build successful!
+```
+
+## Final Verification
+
+```bash
+$ ./gradlew detekt
+# No issues
+
+$ ./gradlew test
+# All tests passed
+```
+
+## Summary
+
+| Metric | Count |
+|--------|-------|
+| Build errors fixed | 3 |
+| Detekt issues fixed | 0 |
+| Files modified | 2 |
+| Remaining issues | 0 |
+
+Build Status: ✅ SUCCESS
+````
+
+## Common Errors Fixed
+
+| Error | Typical Fix |
+|-------|-------------|
+| `Unresolved reference: X` | Add import or dependency |
+| `Type mismatch` | Fix type conversion or assignment |
+| `'when' must be exhaustive` | Add missing sealed class branches |
+| `Suspend function can only be called from coroutine` | Add `suspend` modifier |
+| `Smart cast impossible` | Use local `val` or `let` |
+| `None of the following candidates is applicable` | Fix argument types |
+| `Could not resolve dependency` | Fix version or add repository |
+
+## Fix Strategy
+
+1. **Build errors first** - Code must compile
+2. **Detekt violations second** - Fix code quality issues
+3. **ktlint warnings third** - Fix formatting
+4. **One fix at a time** - Verify each change
+5. **Minimal changes** - Don't refactor, just fix
+
+## Stop Conditions
+
+The agent will stop and report if:
+- Same error persists after 3 attempts
+- Fix introduces more errors
+- Requires architectural changes
+- Missing external dependencies
+
+## Related Commands
+
+- `/kotlin-test` - Run tests after build succeeds
+- `/kotlin-review` - Review code quality
+- `/verify` - Full verification loop
+
+## Related
+
+- Agent: `agents/kotlin-build-resolver.md`
+- Skill: `skills/kotlin-patterns/`
--- a/commands/kotlin-review.md
+++ b/commands/kotlin-review.md
@@ -0,0 +1,140 @@
+---
+description: Comprehensive Kotlin code review for idiomatic patterns, null safety, coroutine safety, and security. Invokes the kotlin-reviewer agent.
+---
+
+# Kotlin Code Review
+
+This command invokes the **kotlin-reviewer** agent for comprehensive Kotlin-specific code review.
+
+## What This Command Does
+
+1. **Identify Kotlin Changes**: Find modified `.kt` and `.kts` files via `git diff`
+2. **Run Build & Static Analysis**: Execute `./gradlew build`, `detekt`, `ktlintCheck`
+3. **Security Scan**: Check for SQL injection, command injection, hardcoded secrets
+4. **Null Safety Review**: Analyze `!!` usage, platform type handling, unsafe casts
+5. **Coroutine Review**: Check structured concurrency, dispatcher usage, cancellation
+6. **Generate Report**: Categorize issues by severity
+
+## When to Use
+
+Use `/kotlin-review` when:
+- After writing or modifying Kotlin code
+- Before committing Kotlin changes
+- Reviewing pull requests with Kotlin code
+- Onboarding to a new Kotlin codebase
+- Learning idiomatic Kotlin patterns
+
+## Review Categories
+
+### CRITICAL (Must Fix)
+- SQL/Command injection vulnerabilities
+- Force-unwrap `!!` without justification
+- Platform type null safety violations
+- GlobalScope usage (structured concurrency violation)
+- Hardcoded credentials
+- Unsafe deserialization
+
+### HIGH (Should Fix)
+- Mutable state where immutable suffices
+- Blocking calls inside coroutine context
+- Missing cancellation checks in long loops
+- Non-exhaustive `when` on sealed types
+- Large functions (>50 lines)
+- Deep nesting (>4 levels)
+
+### MEDIUM (Consider)
+- Non-idiomatic Kotlin (Java-style patterns)
+- Missing trailing commas
+- Scope function misuse or nesting
+- Missing sequence for large collection chains
+- Redundant explicit types
+
+## Automated Checks Run
+
+```bash
+# Build check
+./gradlew build
+
+# Static analysis
+./gradlew detekt
+
+# Formatting check
+./gradlew ktlintCheck
+
+# Tests
+./gradlew test
+```
+
+## Example Usage
+
+````text
+User: /kotlin-review
+
+Agent:
+# Kotlin Code Review Report
+
+## Files Reviewed
+- src/main/kotlin/com/example/service/UserService.kt (modified)
+- src/main/kotlin/com/example/routes/UserRoutes.kt (modified)
+
+## Static Analysis Results
+✓ Build: Successful
+✓ detekt: No issues
+⚠ ktlint: 2 formatting warnings
+
+## Issues Found
+
+[CRITICAL] Force-Unwrap Null Safety
+File: src/main/kotlin/com/example/service/UserService.kt:28
+Issue: Using !! on nullable repository result
+```kotlin
+val user = repository.findById(id)!!  // NPE risk
+```
+Fix: Use safe call with error handling
+```kotlin
+val user = repository.findById(id)
+    ?: throw UserNotFoundException("User $id not found")
+```
+
+[HIGH] GlobalScope Usage
+File: src/main/kotlin/com/example/routes/UserRoutes.kt:45
+Issue: Using GlobalScope breaks structured concurrency
+```kotlin
+GlobalScope.launch {
+    notificationService.sendWelcome(user)
+}
+```
+Fix: Use the call's coroutine scope
+```kotlin
+launch {
+    notificationService.sendWelcome(user)
+}
+```
+
+## Summary
+- CRITICAL: 1
+- HIGH: 1
+- MEDIUM: 0
+
+Recommendation: ❌ Block merge until CRITICAL issue is fixed
+````
+
+## Approval Criteria
+
+| Status | Condition |
+|--------|-----------|
+| ✅ Approve | No CRITICAL or HIGH issues |
+| ⚠️ Warning | Only MEDIUM issues (merge with caution) |
+| ❌ Block | CRITICAL or HIGH issues found |
+
+## Integration with Other Commands
+
+- Use `/kotlin-test` first to ensure tests pass
+- Use `/kotlin-build` if build errors occur
+- Use `/kotlin-review` before committing
+- Use `/code-review` for non-Kotlin-specific concerns
+
+## Related
+
+- Agent: `agents/kotlin-reviewer.md`
+- Skills: `skills/kotlin-patterns/`, `skills/kotlin-testing/`
--- a/commands/kotlin-test.md
+++ b/commands/kotlin-test.md
@@ -0,0 +1,312 @@
+---
+description: Enforce TDD workflow for Kotlin. Write Kotest tests first, then implement. Verify 80%+ coverage with Kover.
+---
+
+# Kotlin TDD Command
+
+This command enforces test-driven development methodology for Kotlin code using Kotest, MockK, and Kover.
+
+## What This Command Does
+
+1. **Define Types/Interfaces**: Scaffold function signatures first
+2. **Write Kotest Tests**: Create comprehensive test specs (RED)
+3. **Run Tests**: Verify tests fail for the right reason
+4. **Implement Code**: Write minimal code to pass (GREEN)
+5. **Refactor**: Improve while keeping tests green
+6. **Check Coverage**: Ensure 80%+ coverage with Kover
+
+## When to Use
+
+Use `/kotlin-test` when:
+- Implementing new Kotlin functions or classes
+- Adding test coverage to existing Kotlin code
+- Fixing bugs (write failing test first)
+- Building critical business logic
+- Learning TDD workflow in Kotlin
+
+## TDD Cycle
+
+```
+RED     -> Write failing Kotest test
+GREEN   -> Implement minimal code to pass
+REFACTOR -> Improve code, tests stay green
+REPEAT  -> Next test case
+```
+
+## Example Session
+
+````text
+User: /kotlin-test I need a function to validate user registration requests
+
+Agent:
+# TDD Session: Registration Validator
+
+## Step 1: Define Interface
+
+```kotlin
+// validator/RegistrationValidator.kt
+package com.example.validator
+
+data class RegistrationRequest(
+    val name: String,
+    val email: String,
+    val password: String,
+)
+
+sealed class ValidationResult {
+    data object Valid : ValidationResult()
+    data class Invalid(val errors: List<String>) : ValidationResult()
+}
+
+fun validateRegistration(request: RegistrationRequest): ValidationResult {
+    TODO("not implemented")
+}
+```
+
+## Step 2: Write Kotest Tests (RED)
+
+```kotlin
+// validator/RegistrationValidatorTest.kt
+package com.example.validator
+
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+import io.kotest.matchers.types.shouldBeInstanceOf
+
+class RegistrationValidatorTest : FunSpec({
+    test("valid registration returns Valid") {
+        val request = RegistrationRequest(
+            name = "Alice",
+            email = "alice@example.com",
+            password = "SecureP@ss1",
+        )
+
+        val result = validateRegistration(request)
+
+        result.shouldBeInstanceOf<ValidationResult.Valid>()
+    }
+
+    test("blank name returns Invalid") {
+        val request = RegistrationRequest(
+            name = "",
+            email = "alice@example.com",
+            password = "SecureP@ss1",
+        )
+
+        val result = validateRegistration(request)
+
+        val invalid = result.shouldBeInstanceOf<ValidationResult.Invalid>()
+        invalid.errors shouldBe listOf("Name is required")
+    }
+
+    test("invalid email returns Invalid") {
+        val request = RegistrationRequest(
+            name = "Alice",
+            email = "not-an-email",
+            password = "SecureP@ss1",
+        )
+
+        val result = validateRegistration(request)
+
+        val invalid = result.shouldBeInstanceOf<ValidationResult.Invalid>()
+        invalid.errors shouldBe listOf("Invalid email format")
+    }
+
+    test("short password returns Invalid") {
+        val request = RegistrationRequest(
+            name = "Alice",
+            email = "alice@example.com",
+            password = "short",
+        )
+
+        val result = validateRegistration(request)
+
+        val invalid = result.shouldBeInstanceOf<ValidationResult.Invalid>()
+        invalid.errors shouldBe listOf("Password must be at least 8 characters")
+    }
+
+    test("multiple errors returns all errors") {
+        val request = RegistrationRequest(
+            name = "",
+            email = "bad",
+            password = "short",
+        )
+
+        val result = validateRegistration(request)
+
+        val invalid = result.shouldBeInstanceOf<ValidationResult.Invalid>()
+        invalid.errors.size shouldBe 3
+    }
+})
+```
+
+## Step 3: Run Tests - Verify FAIL
+
+```bash
+$ ./gradlew test
+
+RegistrationValidatorTest > valid registration returns Valid FAILED
+  kotlin.NotImplementedError: An operation is not implemented
+
+FAILED (5 tests, 0 passed, 5 failed)
+```
+
+✓ Tests fail as expected (NotImplementedError).
+
+## Step 4: Implement Minimal Code (GREEN)
+
+```kotlin
+// validator/RegistrationValidator.kt
+package com.example.validator
+
+private val EMAIL_REGEX = Regex("^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$")
+private const val MIN_PASSWORD_LENGTH = 8
+
+fun validateRegistration(request: RegistrationRequest): ValidationResult {
+    val errors = buildList {
+        if (request.name.isBlank()) add("Name is required")
+        if (!EMAIL_REGEX.matches(request.email)) add("Invalid email format")
+        if (request.password.length < MIN_PASSWORD_LENGTH) add("Password must be at least $MIN_PASSWORD_LENGTH characters")
+    }
+
+    return if (errors.isEmpty()) ValidationResult.Valid
+    else ValidationResult.Invalid(errors)
+}
+```
+
+## Step 5: Run Tests - Verify PASS
+
+```bash
+$ ./gradlew test
+
+RegistrationValidatorTest > valid registration returns Valid PASSED
+RegistrationValidatorTest > blank name returns Invalid PASSED
+RegistrationValidatorTest > invalid email returns Invalid PASSED
+RegistrationValidatorTest > short password returns Invalid PASSED
+RegistrationValidatorTest > multiple errors returns all errors PASSED
+
+PASSED (5 tests, 5 passed, 0 failed)
+```
+
+✓ All tests passing!
+
+## Step 6: Check Coverage
+
+```bash
+$ ./gradlew koverHtmlReport
+
+Coverage: 100.0% of statements
+```
+
+✓ Coverage: 100%
+
+## TDD Complete!
+````
+
+## Test Patterns
+
+### StringSpec (Simplest)
+
+```kotlin
+class CalculatorTest : StringSpec({
+    "add two positive numbers" {
+        Calculator.add(2, 3) shouldBe 5
+    }
+})
+```
+
+### BehaviorSpec (BDD)
+
+```kotlin
+class OrderServiceTest : BehaviorSpec({
+    Given("a valid order") {
+        When("placed") {
+            Then("should be confirmed") { /* ... */ }
+        }
+    }
+})
+```
+
+### Data-Driven Tests
+
+```kotlin
+class ParserTest : FunSpec({
+    context("valid inputs") {
+        withData("2026-01-15", "2026-12-31", "2000-01-01") { input ->
+            parseDate(input).shouldNotBeNull()
+        }
+    }
+})
+```
+
+### Coroutine Testing
+
+```kotlin
+class AsyncServiceTest : FunSpec({
+    test("concurrent fetch completes") {
+        runTest {
+            val result = service.fetchAll()
+            result.shouldNotBeEmpty()
+        }
+    }
+})
+```
+
+## Coverage Commands
+
+```bash
+# Run tests with coverage
+./gradlew koverHtmlReport
+
+# Verify coverage thresholds
+./gradlew koverVerify
+
+# XML report for CI
+./gradlew koverXmlReport
+
+# Open HTML report
+open build/reports/kover/html/index.html
+
+# Run specific test class
+./gradlew test --tests "com.example.UserServiceTest"
+
+# Run with verbose output
+./gradlew test --info
+```
+
+## Coverage Targets
+
+| Code Type | Target |
+|-----------|--------|
+| Critical business logic | 100% |
+| Public APIs | 90%+ |
+| General code | 80%+ |
+| Generated code | Exclude |
+
+## TDD Best Practices
+
+**DO:**
+- Write test FIRST, before any implementation
+- Run tests after each change
+- Use Kotest matchers for expressive assertions
+- Use MockK's `coEvery`/`coVerify` for suspend functions
+- Test behavior, not implementation details
+- Include edge cases (empty, null, max values)
+
+**DON'T:**
+- Write implementation before tests
+- Skip the RED phase
+- Test private functions directly
+- Use `Thread.sleep()` in coroutine tests
+- Ignore flaky tests
+
+## Related Commands
+
+- `/kotlin-build` - Fix build errors
+- `/kotlin-review` - Review code after implementation
+- `/verify` - Run full verification loop
+
+## Related
+
+- Skill: `skills/kotlin-testing/`
+- Skill: `skills/tdd-workflow/`