app: port tests to Ktor

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

app/build.gradle.kts

@@ -99,6 +99,7 @@ dependencies {
   implementation(Dependencies.ThirdParty.customtabs)
   implementation(Dependencies.ThirdParty.Roomigrant.runtime)
   testImplementation(Dependencies.Testing.junit)
+  testImplementation(Dependencies.Kotlin.Ktor.clientTest)
   androidTestImplementation(Dependencies.Testing.daggerHilt)
   androidTestImplementation(Dependencies.Testing.uiTest)
 }

app/src/test/java/dev/msfjarvis/lobsters/data/api/KtorLobstersApiTest.kt

@@ -0,0 +1,78 @@
+package dev.msfjarvis.lobsters.data.api
+
+import dev.msfjarvis.lobsters.util.TestUtils
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respond
+import io.ktor.client.features.json.JsonFeature
+import io.ktor.client.features.json.serializer.KotlinxSerializer
+import io.ktor.http.fullPath
+import io.ktor.http.headersOf
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import kotlinx.coroutines.runBlocking
+import org.junit.AfterClass
+import org.junit.BeforeClass
+import org.junit.Test
+
+class KtorLobstersApiTest {
+
+  companion object {
+    @JvmStatic
+    private lateinit var client: HttpClient
+    @JvmStatic
+    private lateinit var apiClient: LobstersApi
+
+    @JvmStatic
+    @BeforeClass
+    fun setUp() {
+      client = HttpClient(MockEngine) {
+        install(JsonFeature) {
+          serializer = KotlinxSerializer()
+        }
+        engine {
+          addHandler { request ->
+            when (request.url.fullPath) {
+              "/hottest.json?page=1" -> {
+                val responseHeaders = headersOf("Content-Type" to listOf("application/json"))
+                respond(TestUtils.getJson("hottest.json"), headers = responseHeaders)
+              }
+              else -> error("Unhandled ${request.url.fullPath}")
+            }
+          }
+        }
+      }
+      apiClient = KtorLobstersApi(client)
+    }
+
+    @JvmStatic
+    @AfterClass
+    fun tearDown() {
+      client.close()
+    }
+  }
+
+  @Test
+  fun `api gets correct number of items`() = runBlocking {
+    val posts = apiClient.getHottestPosts(1)
+    assertEquals(25, posts.size)
+  }
+
+  @Test
+  fun `no moderator posts in test data`() = runBlocking {
+    val posts = apiClient.getHottestPosts(1)
+    val moderatorPosts = posts.asSequence()
+      .filter { it.submitterUser.isModerator }
+      .toSet()
+    assertTrue(moderatorPosts.isEmpty())
+  }
+
+  @Test
+  fun `posts with no urls`() = runBlocking {
+    val posts = apiClient.getHottestPosts(1)
+    val commentsOnlyPosts = posts.asSequence()
+      .filter { it.url.isEmpty() }
+      .toSet()
+    assertEquals(2, commentsOnlyPosts.size)
+  }
+}

app/src/test/java/dev/msfjarvis/lobsters/util/TestUtils.kt

@@ -0,0 +1,12 @@
+package dev.msfjarvis.lobsters.util
+
+import java.io.File
+
+object TestUtils {
+  fun getJson(path: String): String {
+    // Load the JSON response
+    val uri = javaClass.classLoader.getResource(path)
+    val file = File(uri.path)
+    return String(file.readBytes())
+  }
+}

buildSrc/src/main/java/Dependencies.kt

@@ -24,6 +24,7 @@ object Dependencies {
       const val clientJson = "io.ktor:ktor-client-json:$version"
       const val clientSerialization = "io.ktor:ktor-client-serialization:$version"
       const val clientOkHttp = "io.ktor:ktor-client-okhttp:$version"
+      const val clientTest = "io.ktor:ktor-client-mock:$version"
     }
 
     object Serialization {