docs(zh-CN): update

docs/zh-CN/rules/kotlin/testing.md

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+---
+paths:
+  - "**/*.kt"
+  - "**/*.kts"
+---
+
+# Kotlin 测试
+
+> 本文档扩展了 [common/testing.md](../common/testing.md)，补充了 Kotlin 和 Android/KMP 特有的内容。
+
+## 测试框架
+
+* **kotlin.test** 用于跨平台 (KMP) — `@Test`, `assertEquals`, `assertTrue`
+* **JUnit 4/5** 用于 Android 特定测试
+* **Turbine** 用于测试 Flow 和 StateFlow
+* **kotlinx-coroutines-test** 用于协程测试 (`runTest`, `TestDispatcher`)
+
+## 使用 Turbine 测试 ViewModel
+
+```kotlin
+@Test
+fun `loading state emitted then data`() = runTest {
+    val repo = FakeItemRepository()
+    repo.addItem(testItem)
+    val viewModel = ItemListViewModel(GetItemsUseCase(repo))
+
+    viewModel.state.test {
+        assertEquals(ItemListState(), awaitItem())     // initial state
+        viewModel.onEvent(ItemListEvent.Load)
+        assertTrue(awaitItem().isLoading)               // loading
+        assertEquals(listOf(testItem), awaitItem().items) // loaded
+    }
+}
+```
+
+## 使用伪造对象而非模拟对象
+
+优先使用手写的伪造对象，而非模拟框架：
+
+```kotlin
+class FakeItemRepository : ItemRepository {
+    private val items = mutableListOf<Item>()
+    var fetchError: Throwable? = null
+
+    override suspend fun getAll(): Result<List<Item>> {
+        fetchError?.let { return Result.failure(it) }
+        return Result.success(items.toList())
+    }
+
+    override fun observeAll(): Flow<List<Item>> = flowOf(items.toList())
+
+    fun addItem(item: Item) { items.add(item) }
+}
+```
+
+## 协程测试
+
+```kotlin
+@Test
+fun `parallel operations complete`() = runTest {
+    val repo = FakeRepository()
+    val result = loadDashboard(repo)
+    advanceUntilIdle()
+    assertNotNull(result.items)
+    assertNotNull(result.stats)
+}
+```
+
+使用 `runTest` — 它会自动推进虚拟时间并提供 `TestScope`。
+
+## Ktor MockEngine
+
+```kotlin
+val mockEngine = MockEngine { request ->
+    when (request.url.encodedPath) {
+        "/api/items" -> respond(
+            content = Json.encodeToString(testItems),
+            headers = headersOf(HttpHeaders.ContentType, ContentType.Application.Json.toString())
+        )
+        else -> respondError(HttpStatusCode.NotFound)
+    }
+}
+
+val client = HttpClient(mockEngine) {
+    install(ContentNegotiation) { json() }
+}
+```
+
+## Room/SQLDelight 测试
+
+* Room: 使用 `Room.inMemoryDatabaseBuilder()` 进行内存测试
+* SQLDelight: 在 JVM 测试中使用 `JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)`
+
+```kotlin
+@Test
+fun `insert and query items`() = runTest {
+    val driver = JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)
+    Database.Schema.create(driver)
+    val db = Database(driver)
+
+    db.itemQueries.insert("1", "Sample Item", "description")
+    val items = db.itemQueries.getAll().executeAsList()
+    assertEquals(1, items.size)
+}
+```
+
+## 测试命名
+
+使用反引号包裹的描述性名称：
+
+```kotlin
+@Test
+fun `search with empty query returns all items`() = runTest { }
+
+@Test
+fun `delete item emits updated list without deleted item`() = runTest { }
+```
+
+## 测试组织
+
+```
+src/
+├── commonTest/kotlin/     # Shared tests (ViewModel, UseCase, Repository)
+├── androidUnitTest/kotlin/ # Android unit tests (JUnit)
+├── androidInstrumentedTest/kotlin/  # Instrumented tests (Room, UI)
+└── iosTest/kotlin/        # iOS-specific tests
+```
+
+最低测试覆盖率：每个功能都需要覆盖 ViewModel + UseCase。