feat(network): Implement unit tests for TranslationRepository

Author: menny

gradle/libs.versions.toml

@@ -16,6 +16,9 @@ retrofit = "2.11.0"
 okhttp = "4.12.0"
 moshi = "1.15.1"
 androidx_annotation = "1.8.0"
+mockk = "1.13.10"
+kotlinx_coroutines_test = "1.8.0"
+kotlin_test_junit = "1.9.22"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -38,6 +41,9 @@ okhttp-logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-i
 moshi = { group = "com.squareup.moshi", name = "moshi", version.ref = "moshi" }
 moshi-kotlin = { group = "com.squareup.moshi", name = "moshi-kotlin", version.ref = "moshi" }
 androidx-annotation = { group = "androidx.annotation", name = "annotation", version.ref = "androidx_annotation" }
+mockk = { group = "io.mockk", name = "mockk", version.ref = "mockk" }
+kotlinx-coroutines-test = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-test", version.ref = "kotlinx_coroutines_test" }
+kotlin-test-junit = { group = "org.jetbrains.kotlin", name = "kotlin-test-junit", version.ref = "kotlin_test_junit" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "android_gradle_plugin" }

network/build.gradle.kts

@@ -42,6 +42,9 @@ dependencies {
     implementation(libs.moshi.kotlin)
     implementation(libs.androidx.annotation)
     testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+    testImplementation(libs.kotlin.test.junit)
     androidTestImplementation(libs.androidx.test.ext.junit)
     androidTestImplementation(libs.androidx.test.espresso.core)
 }

network/src/test/java/com/anysoftkeyboard/janus/network/TranslationRepositoryTest.kt

@@ -0,0 +1,94 @@
+package com.anysoftkeyboard.janus.network
+
+import com.anysoftkeyboard.janus.database.Translation
+import com.anysoftkeyboard.janus.database.TranslationDao
+import io.mockk.coEvery
+import io.mockk.coVerify
+import io.mockk.mockk
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Test
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+
+class TranslationRepositoryTest {
+
+    private lateinit var wikipediaApi: WikipediaApi
+    private lateinit var translationDao: TranslationDao
+    private lateinit var repository: TranslationRepository
+
+    @Before
+    fun setup() {
+        wikipediaApi = mockk()
+        translationDao = mockk()
+        repository = TranslationRepository(wikipediaApi, translationDao)
+    }
+
+    @Test
+    fun `getTranslation_returnsCachedTranslationWhenAvailable`() = runTest {
+        val sourceWord = "hello"
+        val sourceLang = "en"
+        val targetLang = "es"
+        val cachedTranslation = Translation(
+            id = 1,
+            sourceWord = sourceWord,
+            sourceLangCode = sourceLang,
+            sourceArticleUrl = "url_cached",
+            sourceShortDescription = "desc_cached",
+            sourceSummary = null,
+            translatedWord = "hola",
+            targetLangCode = targetLang,
+            targetArticleUrl = "url_cached",
+            targetShortDescription = "desc_cached",
+            targetSummary = null
+        )
+
+        coEvery { translationDao.findTranslation(sourceWord, sourceLang, targetLang) } returns cachedTranslation
+
+        val result = repository.getTranslation(sourceWord, sourceLang, targetLang)
+
+        assertEquals(cachedTranslation, result)
+        coVerify(exactly = 0) { wikipediaApi.search(any()) }
+        coVerify(exactly = 0) { translationDao.insertTranslation(any()) }
+    }
+
+    @Test
+    fun `getTranslation_fetchesFromNetworkAndCachesWhenNotAvailable`() = runTest {
+        val sourceWord = "hello"
+        val sourceLang = "en"
+        val targetLang = "es"
+        val networkResponse = SearchResponse(
+            query = Query(
+                search = listOf(
+                    SearchResult("Hola", "Spanish for hello")
+                )
+            )
+        )
+
+        coEvery { translationDao.findTranslation(sourceWord, sourceLang, targetLang) } returns null
+        coEvery { wikipediaApi.search(sourceWord) } returns networkResponse
+        coEvery { translationDao.insertTranslation(any()) } returns Unit
+
+        val result = repository.getTranslation(sourceWord, sourceLang, targetLang)
+
+        assertEquals("Hola", result?.translatedWord)
+        coVerify(exactly = 1) { wikipediaApi.search(sourceWord) }
+        coVerify(exactly = 1) { translationDao.insertTranslation(any()) }
+    }
+
+    @Test
+    fun `getTranslation_returnsNullWhenNetworkFailsAndNoCache`() = runTest {
+        val sourceWord = "hello"
+        val sourceLang = "en"
+        val targetLang = "es"
+
+        coEvery { translationDao.findTranslation(sourceWord, sourceLang, targetLang) } returns null
+        coEvery { wikipediaApi.search(sourceWord) } throws RuntimeException("Network error")
+
+        val result = repository.getTranslation(sourceWord, sourceLang, targetLang)
+
+        assertNull(result)
+        coVerify(exactly = 1) { wikipediaApi.search(sourceWord) }
+        coVerify(exactly = 0) { translationDao.insertTranslation(any()) }
+    }
+}