extracting me fetching logic to its own usecase and testing

.idea/inspectionProfiles/Project_Default.xml

@@ -4,6 +4,9 @@
     <inspection_tool class="PreviewAnnotationInFunctionWithParameters" enabled="true" level="ERROR" enabled_by_default="true">
       <option name="composableFile" value="true" />
     </inspection_tool>
+    <inspection_tool class="PreviewApiLevelMustBeValid" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+    </inspection_tool>
     <inspection_tool class="PreviewDimensionRespectsLimit" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="composableFile" value="true" />
     </inspection_tool>
@@ -25,5 +28,6 @@
     <inspection_tool class="PreviewPickerAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
       <option name="composableFile" value="true" />
     </inspection_tool>
+    <inspection_tool class="PrivatePropertyName" enabled="false" level="WEAK WARNING" enabled_by_default="false" />
   </profile>
 </component>

matrix/matrix-http/src/testFixtures/kotlin/fake/FakeHttpResponse.kt

@@ -0,0 +1,16 @@
+package fake
+
+import io.ktor.client.statement.*
+import io.ktor.http.*
+import io.mockk.every
+import io.mockk.mockk
+
+class FakeHttpResponse {
+
+    val instance = mockk<HttpResponse>(relaxed = true)
+
+    fun givenStatus(code: Int) {
+        every { instance.status } returns HttpStatusCode(code, "")
+    }
+
+}

matrix/matrix-http/src/testFixtures/kotlin/fake/FakeMatrixHttpClient.kt

@@ -1,6 +1,7 @@
 package fake
 
 import app.dapk.st.matrix.http.MatrixHttpClient
+import io.ktor.client.plugins.*
 import io.mockk.coEvery
 import io.mockk.mockk
 
@@ -8,4 +9,8 @@ class FakeMatrixHttpClient : MatrixHttpClient by mockk() {
     fun <T : Any> given(request: MatrixHttpClient.HttpRequest<T>, response: T) {
         coEvery { execute(request) } returns response
     }
+
+    fun <T : Any> errors(request: MatrixHttpClient.HttpRequest<T>, cause: Throwable) {
+        coEvery { execute(request) } throws cause
+    }
 }

matrix/matrix-http/src/testFixtures/kotlin/fixture/HttpError.kt

@@ -0,0 +1,14 @@
+package fixture
+
+import fake.FakeHttpResponse
+import io.ktor.client.plugins.*
+
+fun a404HttpError() = ClientRequestException(
+    FakeHttpResponse().apply { givenStatus(404) }.instance,
+    cachedResponseText = ""
+)
+
+fun a403HttpError() = ClientRequestException(
+    FakeHttpResponse().apply { givenStatus(403) }.instance,
+    cachedResponseText = ""
+)

matrix/services/profile/build.gradle

@@ -1,5 +1,14 @@
+plugins { id 'java-test-fixtures' }
 applyMatrixServiceModule(project)
 
 dependencies {
     implementation project(":core")
+
+    kotlinTest(it)
+    kotlinFixtures(it)
+    testImplementation(testFixtures(project(":matrix:common")))
+    testImplementation(testFixtures(project(":matrix:matrix-http")))
+    testImplementation(testFixtures(project(":core")))
+    testFixturesImplementation(testFixtures(project(":matrix:common")))
+    testFixturesImplementation(testFixtures(project(":core")))
 }

matrix/services/profile/src/main/kotlin/app/dapk/st/matrix/room/ProfileService.kt

@@ -10,6 +10,7 @@ import app.dapk.st.matrix.common.CredentialsStore
 import app.dapk.st.matrix.common.HomeServerUrl
 import app.dapk.st.matrix.common.UserId
 import app.dapk.st.matrix.room.internal.DefaultProfileService
+import app.dapk.st.matrix.room.internal.FetchMeUseCase
 
 private val SERVICE_KEY = ProfileService::class
 
@@ -31,8 +32,9 @@ fun MatrixServiceInstaller.installProfileService(
     singletonFlows: SingletonFlows,
     credentialsStore: CredentialsStore,
 ): InstallExtender<ProfileService> {
-    return this.install { (httpClient, _, _, logger) ->
+    return this.install { (httpClient, _, _, _) ->
-        SERVICE_KEY to DefaultProfileService(httpClient, logger, profileStore, singletonFlows, credentialsStore)
+        val fetchMeUseCase = FetchMeUseCase(httpClient, credentialsStore)
+        SERVICE_KEY to DefaultProfileService(profileStore, singletonFlows, fetchMeUseCase)
     }
 }
 

matrix/services/profile/src/main/kotlin/app/dapk/st/matrix/room/internal/DefaultProfileService.kt

@@ -1,22 +1,14 @@
 package app.dapk.st.matrix.room.internal
 
 import app.dapk.st.core.SingletonFlows
-import app.dapk.st.matrix.common.*
-import app.dapk.st.matrix.http.MatrixHttpClient
 import app.dapk.st.matrix.room.ProfileService
 import app.dapk.st.matrix.room.ProfileStore
-import io.ktor.client.call.*
-import io.ktor.client.plugins.*
 import kotlinx.coroutines.flow.first
-import kotlinx.serialization.SerialName
-import kotlinx.serialization.Serializable
 
 internal class DefaultProfileService(
-    private val httpClient: MatrixHttpClient,
-    private val logger: MatrixLogger,
     private val profileStore: ProfileStore,
     private val singletonFlows: SingletonFlows,
-    private val credentialsStore: CredentialsStore,
+    private val fetchMeUseCase: FetchMeUseCase,
 ) : ProfileService {
 
     override suspend fun me(forceRefresh: Boolean): ProfileService.Me {
@@ -29,42 +21,7 @@ internal class DefaultProfileService(
     }
 
     private suspend fun fetchMe(): ProfileService.Me {
-        val credentials = credentialsStore.credentials()!!
+        return fetchMeUseCase.fetchMe()
-        val userId = credentials.userId
-        return runCatching { httpClient.execute(profileRequest(userId)) }.fold(
-            onSuccess = {
-                ProfileService.Me(
-                    userId,
-                    it.displayName,
-                    it.avatarUrl?.convertMxUrToUrl(credentials.homeServer)?.let { AvatarUrl(it) },
-                    homeServerUrl = credentials.homeServer,
-                )
-            },
-            onFailure = {
-                when {
-                    it is ClientRequestException && it.response.status.value == 404 -> {
-                        ProfileService.Me(
-                            userId,
-                            displayName = null,
-                            avatarUrl = null,
-                            homeServerUrl = credentials.homeServer,
-                        )
-                    }
-
-                    else -> throw it
-                }
-            }
-        )
     }
 }
 
-internal fun profileRequest(userId: UserId) = MatrixHttpClient.HttpRequest.httpRequest<ApiMe>(
-    path = "_matrix/client/r0/profile/${userId.value}/",
-    method = MatrixHttpClient.Method.GET,
-)
-
-@Serializable
-internal data class ApiMe(
-    @SerialName("displayname") val displayName: String? = null,
-    @SerialName("avatar_url") val avatarUrl: MxUrl? = null,
-)

matrix/services/profile/src/main/kotlin/app/dapk/st/matrix/room/internal/FetchMeUseCase.kt

@@ -0,0 +1,53 @@
+package app.dapk.st.matrix.room.internal
+
+import app.dapk.st.matrix.common.*
+import app.dapk.st.matrix.http.MatrixHttpClient
+import app.dapk.st.matrix.room.ProfileService
+import io.ktor.client.plugins.*
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+internal class FetchMeUseCase(
+    private val httpClient: MatrixHttpClient,
+    private val credentialsStore: CredentialsStore,
+) {
+    suspend fun fetchMe(): ProfileService.Me {
+        val credentials = credentialsStore.credentials()!!
+        val userId = credentials.userId
+        return runCatching { httpClient.execute(profileRequest(userId)) }.fold(
+            onSuccess = {
+                ProfileService.Me(
+                    userId,
+                    it.displayName,
+                    it.avatarUrl?.convertMxUrToUrl(credentials.homeServer)?.let { AvatarUrl(it) },
+                    homeServerUrl = credentials.homeServer,
+                )
+            },
+            onFailure = {
+                when {
+                    it is ClientRequestException && it.response.status.value == 404 -> {
+                        ProfileService.Me(
+                            userId,
+                            displayName = null,
+                            avatarUrl = null,
+                            homeServerUrl = credentials.homeServer,
+                        )
+                    }
+
+                    else -> throw it
+                }
+            }
+        )
+    }
+}
+
+internal fun profileRequest(userId: UserId) = MatrixHttpClient.HttpRequest.httpRequest<ApiMe>(
+    path = "_matrix/client/r0/profile/${userId.value}/",
+    method = MatrixHttpClient.Method.GET,
+)
+
+@Serializable
+internal data class ApiMe(
+    @SerialName("displayname") val displayName: String? = null,
+    @SerialName("avatar_url") val avatarUrl: MxUrl? = null,
+)

matrix/services/profile/src/test/kotlin/app/dapk/st/matrix/room/internal/FetchMeUseCaseTest.kt

@@ -0,0 +1,78 @@
+package app.dapk.st.matrix.room.internal
+
+import app.dapk.st.matrix.room.ProfileService
+import fake.FakeCredentialsStore
+import fake.FakeMatrixHttpClient
+import fixture.a403HttpError
+import fixture.a404HttpError
+import fixture.aUserCredentials
+import fixture.aUserId
+import kotlinx.coroutines.test.runTest
+import org.amshove.kluent.coInvoking
+import org.amshove.kluent.shouldBeEqualTo
+import org.amshove.kluent.shouldThrow
+import org.junit.Test
+
+private val A_USER_CREDENTIALS = aUserCredentials()
+private val A_USER_ID = aUserId()
+private val AN_API_ME_RESPONSE = ApiMe(
+    displayName = "a display name",
+    avatarUrl = null,
+)
+private val AN_UNHANDLED_ERROR = RuntimeException()
+
+class FetchMeUseCaseTest {
+
+    private val fakeHttpClient = FakeMatrixHttpClient()
+    private val fakeCredentialsStore = FakeCredentialsStore()
+
+    private val useCase = FetchMeUseCase(fakeHttpClient, fakeCredentialsStore)
+
+    @Test
+    fun `when fetching me, then returns Me instance`() = runTest {
+        fakeCredentialsStore.givenCredentials().returns(A_USER_CREDENTIALS)
+        fakeHttpClient.given(profileRequest(aUserId()), AN_API_ME_RESPONSE)
+
+        val result = useCase.fetchMe()
+
+        result shouldBeEqualTo ProfileService.Me(
+            userId = A_USER_ID,
+            displayName = AN_API_ME_RESPONSE.displayName,
+            avatarUrl = null,
+            homeServerUrl = fakeCredentialsStore.credentials()!!.homeServer
+        )
+    }
+
+    @Test
+    fun `given unhandled error, when fetching me, then throws`() = runTest {
+        fakeCredentialsStore.givenCredentials().returns(A_USER_CREDENTIALS)
+        fakeHttpClient.errors(profileRequest(aUserId()), AN_UNHANDLED_ERROR)
+
+        coInvoking { useCase.fetchMe() } shouldThrow AN_UNHANDLED_ERROR
+    }
+
+    @Test
+    fun `given 403, when fetching me, then throws`() = runTest {
+        val error = a403HttpError()
+        fakeCredentialsStore.givenCredentials().returns(A_USER_CREDENTIALS)
+        fakeHttpClient.errors(profileRequest(aUserId()), error)
+
+        coInvoking { useCase.fetchMe() } shouldThrow error
+    }
+
+    @Test
+    fun `given 404, when fetching me, then returns Me instance with empty profile fields`() = runTest {
+        fakeCredentialsStore.givenCredentials().returns(A_USER_CREDENTIALS)
+        fakeHttpClient.errors(profileRequest(aUserId()), a404HttpError())
+
+        val result = useCase.fetchMe()
+
+        result shouldBeEqualTo ProfileService.Me(
+            userId = A_USER_ID,
+            displayName = null,
+            avatarUrl = null,
+            homeServerUrl = fakeCredentialsStore.credentials()!!.homeServer
+        )
+    }
+
+}