Reorder simple response factory fields (#407)

* Reordered SimpleResponseFactory fields to align with MockResponse.
* Made bodyFileName nullable.

Author: EranBoudjnah

app/src/androidTest/java/com/mitteloupe/whoami/server/AppResponseStore.kt

@@ -16,11 +16,14 @@ class AppResponseStore : ResponseStore() {
     override val internalResponseFactories = listOf(
         REQUEST_RESPONSE_GET_IP to MockRequestResponseFactory(
             request = MockRequest(IPIFY_ENDPOINT),
-            responseFactory = SimpleResponseFactory(200, "api/get_ip.json")
+            responseFactory = SimpleResponseFactory(code = 200, bodyFileName = "api/get_ip.json")
         ),
         REQUEST_RESPONSE_GET_IP_DETAILS to MockRequestResponseFactory(
             request = MockRequest("${IPINFO_ENDPOINT}$IP_ADDRESS/geo"),
-            responseFactory = SimpleResponseFactory(200, "api/get_ip_details.json")
+            responseFactory = SimpleResponseFactory(
+                code = 200,
+                bodyFileName = "api/get_ip_details.json"
+            )
         )
     )
 }

architecture/instrumentation-test/src/main/java/com/mitteloupe/whoami/test/server/response/SimpleResponseFactory.kt

@@ -5,11 +5,11 @@ import com.mitteloupe.whoami.test.server.MockResponse
 
 data class SimpleResponseFactory(
     private val code: Int = 200,
-    private val bodyFileName: String = "",
-    private val headers: List<Pair<String, String>> = emptyList()
+    private val headers: List<Pair<String, String>> = emptyList(),
+    private val bodyFileName: String? = null
 ) : MockResponseFactory {
     private val body by lazy {
-        if (bodyFileName.isEmpty()) {
+        if (bodyFileName == null) {
             ""
         } else {
             assetReader.getAssetAsString(bodyFileName)