DATACMNS-1024 - Reinstated root object method lookup behavior in EvaluationContextExtensionInformation.

The switch to Java 8 and thus to Collectors.toMap(…) to assemble the root object's methods as functions broke due to the fact that overloaded methods have the same name which causes a collision in keys when preparing the map of functions.

We now use the same approach as before, of letting later methods trump earlier ones as this fixes the original bug. Filed DATACMNS-1026 to keep track of that problem.

Related tickets: DATACMNS-1026.

src/test/java/org/springframework/data/repository/query/EvaluationContextExtensionInformationUnitTests.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.repository.query;
+
+import java.util.Optional;
+
+import org.junit.Test;
+import org.springframework.data.repository.query.spi.EvaluationContextExtension;
+
+/**
+ * Unit tests for {@link EvaluationContextExtensionInformation}.
+ * 
+ * @author Oliver Gierke
+ */
+public class EvaluationContextExtensionInformationUnitTests {
+
+	@Test // DATACMNS-1024
+	public void supportsMethodOverloadsOnRoot() {
+
+		EvaluationContextExtensionInformation information = new EvaluationContextExtensionInformation(
+				SampleExtension.class);
+
+		Optional<Object> target = Optional.of(new Object());
+
+		information.getRootObjectInformation(target).getFunctions(target);
+	}
+
+	interface SampleExtension extends EvaluationContextExtension {
+
+		@Override
+		SampleRoot getRootObject();
+	}
+
+	interface SampleRoot {
+
+		void someMethod();
+
+		void someMethod(String parameter);
+	}
+}