change base path behaviour

Author: MatKuhr

core/src/main/java/com/sap/ai/sdk/core/DestinationResolver.java

@@ -61,9 +61,12 @@ HttpDestination getDestination() {
 
   @Nonnull
   static HttpDestination fromCustomBaseDestination(@Nonnull final HttpDestination destination) {
-    // for custom base destinations we only add the client type header, since users are allowed to
-    // pass a custom base path
-    return addClientTypeHeader(destination);
+    var enhancedBaseDestination = addClientTypeHeader(destination);
+    val path = enhancedBaseDestination.getUri().getPath();
+    if (path == null || path.isEmpty() || path.equals("/")) {
+      return setBasePath(enhancedBaseDestination);
+    }
+    return enhancedBaseDestination;
   }
 
   @Nonnull

core/src/test/java/com/sap/ai/sdk/core/DestinationResolverTest.java

@@ -7,6 +7,7 @@
 
 import com.sap.cloud.environment.servicebinding.api.ServiceBindingAccessor;
 import com.sap.cloud.environment.servicebinding.api.exception.ServiceBindingAccessException;
+import com.sap.cloud.sdk.cloudplatform.connectivity.DefaultHttpDestination;
 import java.util.List;
 import lombok.val;
 import org.junit.jupiter.api.Test;
@@ -54,4 +55,19 @@ void testNoServiceBindingLoadingThrows() {
     var resolver = new DestinationResolver(mock);
     assertThatThrownBy(resolver::getDestination).isSameAs(exception);
   }
+
+  @Test
+  void testFromCustomBaseDestination() {
+    var destination = DefaultHttpDestination.builder("https://api.ai.sap").build();
+    assertThat(DestinationResolver.fromCustomBaseDestination(destination).getUri())
+        .hasToString("https://api.ai.sap/v2/");
+
+    destination = DefaultHttpDestination.builder("https://api.ai.sap/").build();
+    assertThat(DestinationResolver.fromCustomBaseDestination(destination).getUri())
+        .hasToString("https://api.ai.sap/v2/");
+
+    destination = DefaultHttpDestination.builder("https://api.ai.sap/foo").build();
+    assertThat(DestinationResolver.fromCustomBaseDestination(destination).getUri())
+        .hasToString("https://api.ai.sap/foo");
+  }
 }