BIT-405: AuthTokenInterceptor (#57)

app/src/main/java/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryImpl.kt

@@ -7,6 +7,7 @@ import com.x8bit.bitwarden.data.auth.datasource.network.api.IdentityApi
 import com.x8bit.bitwarden.data.auth.datasource.network.model.AuthState
 import com.x8bit.bitwarden.data.auth.datasource.network.model.LoginResult
 import com.x8bit.bitwarden.data.auth.datasource.network.model.PreLoginRequestJson
+import com.x8bit.bitwarden.data.platform.datasource.network.interceptor.AuthTokenInterceptor
 import com.x8bit.bitwarden.data.platform.util.flatMap
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -22,6 +23,7 @@ class AuthRepositoryImpl @Inject constructor(
     private val accountsApi: AccountsApi,
     private val identityApi: IdentityApi,
     private val bitwardenSdkClient: Client,
+    private val authTokenInterceptor: AuthTokenInterceptor,
 ) : AuthRepository {
 
     private val mutableAuthStateFlow = MutableStateFlow<AuthState>(AuthState.Unauthenticated)
@@ -55,6 +57,8 @@ class AuthRepositoryImpl @Inject constructor(
                 LoginResult.Error
             },
             onSuccess = {
+                // TODO: Create intermediate class for providing auth token to interceptor (BIT-411)
+                authTokenInterceptor.authToken = it.accessToken
                 mutableAuthStateFlow.value = AuthState.Authenticated(it.accessToken)
                 LoginResult.Success
             },

app/src/main/java/com/x8bit/bitwarden/data/platform/datasource/network/di/NetworkModule.kt

@@ -5,6 +5,7 @@ import com.x8bit.bitwarden.data.auth.datasource.network.api.AccountsApi
 import com.x8bit.bitwarden.data.auth.datasource.network.api.IdentityApi
 import com.x8bit.bitwarden.data.platform.datasource.network.api.ConfigApi
 import com.x8bit.bitwarden.data.platform.datasource.network.core.ResultCallAdapterFactory
+import com.x8bit.bitwarden.data.platform.datasource.network.interceptor.AuthTokenInterceptor
 import dagger.Module
 import dagger.Provides
 import dagger.hilt.InstallIn
@@ -15,6 +16,7 @@ import okhttp3.OkHttpClient
 import okhttp3.logging.HttpLoggingInterceptor
 import retrofit2.Retrofit
 import retrofit2.create
+import javax.inject.Named
 import javax.inject.Singleton
 
 /**
@@ -25,45 +27,74 @@ import javax.inject.Singleton
 @InstallIn(SingletonComponent::class)
 object NetworkModule {
 
-    @Provides
-    @Singleton
-    fun providesAccountsApiService(retrofit: Retrofit): AccountsApi = retrofit.create()
+    private const val AUTHORIZED = "authorized"
+    private const val UNAUTHORIZED = "unauthorized"
 
     @Provides
     @Singleton
-    fun providesConfigApiService(retrofit: Retrofit): ConfigApi = retrofit.create()
+    fun providesAccountsApiService(@Named(UNAUTHORIZED) retrofit: Retrofit): AccountsApi =
+        retrofit.create()
 
     @Provides
     @Singleton
-    fun providesIdentityApiService(retrofit: Retrofit): IdentityApi = retrofit.create()
+    fun providesConfigApiService(@Named(UNAUTHORIZED) retrofit: Retrofit): ConfigApi =
+        retrofit.create()
 
     @Provides
     @Singleton
-    fun provideOkHttpClient(): OkHttpClient {
-        return OkHttpClient.Builder()
-            .addInterceptor(
+    fun providesIdentityApiService(@Named(UNAUTHORIZED) retrofit: Retrofit): IdentityApi =
+        retrofit.create()
+
+    @Provides
+    @Singleton
+    fun providesAuthTokenInterceptor(): AuthTokenInterceptor = AuthTokenInterceptor()
+
+    @Provides
+    @Singleton
+    fun providesOkHttpClientBuilder(): OkHttpClient.Builder =
+        OkHttpClient.Builder().addInterceptor(
             HttpLoggingInterceptor().apply {
                 setLevel(HttpLoggingInterceptor.Level.BODY)
             },
         )
-            .build()
+
+    @Provides
+    @Singleton
+    fun providesRetrofitBuilder(
+        json: Json,
+    ): Retrofit.Builder {
+        val contentType = "application/json".toMediaType()
+        return Retrofit.Builder().baseUrl("https://api.bitwarden.com")
+            .addConverterFactory(json.asConverterFactory(contentType))
+            .addCallAdapterFactory(ResultCallAdapterFactory())
     }
 
     @Provides
     @Singleton
-    fun provideRetrofit(
-        okHttpClient: OkHttpClient,
-        json: Json,
-    ): Retrofit {
-        val contentType = "application/json".toMediaType()
-
-        return Retrofit.Builder()
-            .baseUrl("https://api.bitwarden.com")
-            .client(okHttpClient)
-            .addConverterFactory(json.asConverterFactory(contentType))
-            .addCallAdapterFactory(ResultCallAdapterFactory())
+    @Named(UNAUTHORIZED)
+    fun providesUnauthorizedRetrofit(
+        okHttpClientBuilder: OkHttpClient.Builder,
+        retrofitBuilder: Retrofit.Builder,
+    ): Retrofit =
+        retrofitBuilder
+            .client(
+                okHttpClientBuilder.build(),
+            )
+            .build()
+
+    @Provides
+    @Singleton
+    @Named(AUTHORIZED)
+    fun providesAuthorizedRetrofit(
+        okHttpClientBuilder: OkHttpClient.Builder,
+        retrofitBuilder: Retrofit.Builder,
+        authTokenInterceptor: AuthTokenInterceptor,
+    ): Retrofit =
+        retrofitBuilder
+            .client(
+                okHttpClientBuilder.addInterceptor(authTokenInterceptor).build(),
+            )
             .build()
-    }
 
     @Provides
     @Singleton

app/src/main/java/com/x8bit/bitwarden/data/platform/datasource/network/interceptor/AuthTokenInterceptor.kt

@@ -0,0 +1,29 @@
+package com.x8bit.bitwarden.data.platform.datasource.network.interceptor
+
+import okhttp3.Interceptor
+import okhttp3.Response
+import java.io.IOException
+import javax.inject.Singleton
+/**
+ * Interceptor responsible for adding the auth token(Bearer) to API requests.
+ */
+@Singleton
+class AuthTokenInterceptor : Interceptor {
+    /**
+     * The auth token to be added to API requests.
+     */
+    var authToken: String? = null
+
+    private val missingTokenMessage = "Auth token is missing!"
+
+    override fun intercept(chain: Interceptor.Chain): Response {
+        val token = authToken ?: throw IOException(IllegalStateException(missingTokenMessage))
+        val request = chain
+            .request()
+            .newBuilder()
+            .addHeader("Authorization", "Bearer $token")
+            .build()
+        return chain
+            .proceed(request)
+    }
+}

app/src/test/java/com/x8bit/bitwarden/data/platform/datasource/network/interceptor/AuthTokenInterceptorTest.kt

@@ -0,0 +1,43 @@
+package com.x8bit.bitwarden.data.platform.datasource.network.interceptor
+
+import junit.framework.TestCase.assertEquals
+import okhttp3.Request
+import org.junit.Assert.assertThrows
+import org.junit.Test
+import java.io.IOException
+import javax.inject.Singleton
+
+@Singleton
+class AuthTokenInterceptorTest {
+    private val interceptor: AuthTokenInterceptor = AuthTokenInterceptor()
+    private val mockAuthToken = "yourAuthToken"
+    private val request: Request = Request
+        .Builder()
+        .url("http://localhost")
+        .build()
+
+    @Test
+    fun `intercept should add the auth token when set`() {
+        interceptor.authToken = mockAuthToken
+        val response = interceptor.intercept(
+            chain = FakeInterceptorChain(request = request),
+        )
+        assertEquals(
+            "Bearer $mockAuthToken",
+            response.request.header("Authorization"),
+        )
+    }
+
+    @Test
+    fun `intercept should throw an exception when an auth token is missing`() {
+        val throwable = assertThrows(IOException::class.java) {
+            interceptor.intercept(
+                chain = FakeInterceptorChain(request = request),
+            )
+        }
+        assertEquals(
+            "Auth token is missing!",
+            throwable.cause?.message,
+        )
+    }
+}

app/src/test/java/com/x8bit/bitwarden/data/platform/datasource/network/interceptor/FakeInterceptorChain.kt

@@ -0,0 +1,69 @@
+package com.x8bit.bitwarden.data.platform.datasource.network.interceptor
+
+import okhttp3.Call
+import okhttp3.Connection
+import okhttp3.Interceptor
+import okhttp3.Protocol
+import okhttp3.Request
+import okhttp3.Response
+import java.util.concurrent.TimeUnit
+
+/**
+ * Helper class for implementing a [Interceptor.Chain] in a way that a [Request] passed in to
+ * [proceed] will be returned in a valid [Response] object that can be queried. This wrapping is
+ * performed by the [responseProvider].
+ */
+class FakeInterceptorChain(
+    private val request: Request,
+    private val responseProvider: (Request) -> Response = DEFAULT_RESPONSE_PROVIDER,
+) : Interceptor.Chain {
+    override fun request(): Request = request
+
+    override fun proceed(request: Request): Response = responseProvider(request)
+
+    override fun connection(): Connection = notImplemented()
+
+    override fun call(): Call = notImplemented()
+
+    override fun connectTimeoutMillis(): Int = notImplemented()
+
+    override fun withConnectTimeout(
+        timeout: Int,
+        unit: TimeUnit,
+    ): Interceptor.Chain = notImplemented()
+
+    override fun readTimeoutMillis(): Int = notImplemented()
+
+    override fun withReadTimeout(
+        timeout: Int,
+        unit: TimeUnit,
+    ): Interceptor.Chain = notImplemented()
+
+    override fun writeTimeoutMillis(): Int = notImplemented()
+
+    override fun withWriteTimeout(
+        timeout: Int,
+        unit: TimeUnit,
+    ): Interceptor.Chain = notImplemented()
+
+    private fun notImplemented(): Nothing {
+        throw NotImplementedError("This is not yet required by tests")
+    }
+
+    companion object {
+        /**
+         * A default response provider that provides a basic successful response. This is useful
+         * when the details of the response are not as important as retrieving the [Request] that
+         * was used to build it.
+         */
+        val DEFAULT_RESPONSE_PROVIDER: (Request) -> Response = { request ->
+            Response
+                .Builder()
+                .code(200)
+                .message("OK")
+                .protocol(Protocol.HTTP_1_1)
+                .request(request)
+                .build()
+        }
+    }
+}