fix: avoid mutating resource paths in ODataRequestCount

Author: Louis-Stegra

datamodel/odata-client/src/main/java/com/sap/cloud/sdk/datamodel/odata/client/request/ODataRequestCount.java

@@ -54,7 +54,7 @@ public ODataRequestCount(
         @Nullable final String encodedQuery,
         @Nonnull final ODataProtocol protocol )
     {
-        super(servicePath, resourcePath.addSegment("$count"), encodedQuery, protocol);
+        super(servicePath, appendCountResourcePath(resourcePath), encodedQuery, protocol);
     }
 
     /**
@@ -74,8 +74,24 @@ public ODataRequestCount(
     {
         this(
             servicePath,
-            resourcePath.addSegment(query.getEntityOrPropertyName()),
+            appendResourcePath(resourcePath, query.getEntityOrPropertyName()),
             query.getEncodedQueryString(),
             query.getProtocol());
     }
+
+    @Nonnull
+    private static ODataResourcePath appendCountResourcePath( @Nonnull final ODataResourcePath resourcePath )
+    {
+        return appendResourcePath(resourcePath, "$count");
+    }
+
+    @Nonnull
+    private static
+        ODataResourcePath
+        appendResourcePath( @Nonnull final ODataResourcePath resourcePath, @Nonnull final String segment )
+    {
+        final ODataResourcePath appendedPath = new ODataResourcePath();
+        resourcePath.getSegments().forEach(s -> appendedPath.addSegment(s._1, s._2));
+        return appendedPath.addSegment(segment);
+    }
 }

datamodel/odata-client/src/test/java/com/sap/cloud/sdk/datamodel/odata/client/request/ODataRequestCountTest.java

@@ -92,4 +92,14 @@ void testConstructorWithStructuredQuery()
         assertThat(actual).isEqualTo(expected);
         assertThat(actual.getQueryString()).isEqualTo(expected.getQueryString());
     }
+
+    @Test
+    void testConstructorDoesNotMutateResourcePath()
+    {
+        final ODataResourcePath resourcePath = ODataResourcePath.of(ENTITY_NAME);
+
+        new ODataRequestCount(SERVICE_PATH, resourcePath, "", ODataProtocol.V4);
+
+        assertThat(resourcePath.toString()).isEqualTo("/" + ENTITY_NAME);
+    }
 }

datamodel/odata-v4/odata-v4-core/src/test/java/com/sap/cloud/sdk/datamodel/odatav4/core/NestedEntityTest.java

@@ -174,6 +174,19 @@ void testCountNestedTrip()
         assertThat(count.getRelativeUri()).hasToString("/TripPinServiceRW/People('russellwhyte')/Trips/$count");
     }
 
+    @Test
+    void testCountNestedTripToRequestIsStable()
+    {
+        final Person personByKey = Person.builder().userName("russellwhyte").build();
+        final CountRequestBuilder<Trip> countBuilder =
+            service.forEntity(personByKey).navigateTo(Person.TO_TRIPS).count();
+
+        assertThat(countBuilder.toRequest().getRelativeUri())
+            .hasToString("/TripPinServiceRW/People('russellwhyte')/Trips/$count");
+        assertThat(countBuilder.toRequest().getRelativeUri())
+            .hasToString("/TripPinServiceRW/People('russellwhyte')/Trips/$count");
+    }
+
     @Test
     void testGetByKeyNestedPlanItem()
     {