[android] backend: normalize base url

android/backend/src/main/java/net/buzzert/kordophone/backend/server/APIClient.kt

@@ -104,8 +104,10 @@ class APIClientFactory {
                 return InvalidConfigurationAPIClient(InvalidConfigurationAPIClient.Issue.NOT_CONFIGURED)
             }
 
+            val normalizedServerString = serverString.ensureTrailingSlash()
+
             // Try to parse server string
-            val serverURL = HttpUrl.parse(serverString)
+            val serverURL = HttpUrl.parse(normalizedServerString)
                 ?: return InvalidConfigurationAPIClient(InvalidConfigurationAPIClient.Issue.INVALID_HOST_URL)
 
             return RetrofitAPIClient(serverURL.url(), authentication)
@@ -113,6 +115,10 @@ class APIClientFactory {
     }
 }
 
+private fun String.ensureTrailingSlash(): String {
+    return if (endsWith("/")) this else "$this/"
+}
+
 // TODO: Is this a dumb idea?
 class InvalidConfigurationAPIClient(val issue: Issue): APIClient {
     enum class Issue {
@@ -215,4 +221,4 @@ fun URL.authenticatedWebSocketURL(serverPath: String, params: Map<String, String
     }
 
     return URL(requestURL.build().toString())
-}
+}

android/backend/src/test/java/net/buzzert/kordophone/backend/BackendTests.kt

@@ -11,6 +11,7 @@ import net.buzzert.kordophone.backend.db.CachedChatDatabase
 import net.buzzert.kordophone.backend.model.Message
 import net.buzzert.kordophone.backend.model.OutgoingMessage
 import net.buzzert.kordophone.backend.server.APIClient
+import net.buzzert.kordophone.backend.server.APIClientFactory
 import net.buzzert.kordophone.backend.server.APIInterface
 import net.buzzert.kordophone.backend.server.Authentication
 import net.buzzert.kordophone.backend.server.ChatRepository
@@ -38,6 +39,16 @@ class BackendTests {
         return Pair(repository, mockServer)
     }
 
+    @Test
+    fun testCreateClientAcceptsBaseUrlWithoutTrailingSlash() {
+        val client = APIClientFactory.createClient(
+            "https://example.com/api",
+            Authentication("test", "test")
+        )
+
+        assertTrue(client.isConfigured)
+    }
+
     @Test
     fun testGetVersion() = runBlocking {
         val (repository, mockServer) = mockRepository()
@@ -342,4 +353,4 @@ class BackendTests {
             assertEquals(messagesToGenerate, allMessages.count())
         }
     }
-}
+}