Polish test to request the type under test

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/TypeUtilsTests.java

@@ -20,15 +20,12 @@ import java.io.IOException;
 import java.time.Duration;
 import java.util.function.BiConsumer;
 
-import javax.annotation.processing.RoundEnvironment;
-import javax.lang.model.element.Element;
-import javax.lang.model.element.TypeElement;
-
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.configurationprocessor.TypeUtils.TypeDescriptor;
+import org.springframework.boot.configurationprocessor.test.RoundEnvironmentTester;
 import org.springframework.boot.configurationprocessor.test.TestableAnnotationProcessor;
 import org.springframework.boot.configurationsample.generic.AbstractGenericProperties;
 import org.springframework.boot.configurationsample.generic.AbstractIntermediateGenericProperties;
@@ -50,53 +47,51 @@ public class TypeUtilsTests {
 	@Test
 	public void resolveTypeDescriptorOnConcreteClass() throws IOException {
 		process(SimpleGenericProperties.class, (roundEnv, typeUtils) -> {
-			for (Element rootElement : roundEnv.getRootElements()) {
-				TypeDescriptor typeDescriptor = typeUtils
-						.resolveTypeDescriptor((TypeElement) rootElement);
-				assertThat(typeDescriptor.getGenerics().keySet().stream()
-						.map(Object::toString)).containsOnly("A", "B", "C");
-				assertThat(typeDescriptor.resolveGeneric("A"))
-						.hasToString(String.class.getName());
-				assertThat(typeDescriptor.resolveGeneric("B"))
-						.hasToString(Integer.class.getName());
-				assertThat(typeDescriptor.resolveGeneric("C"))
-						.hasToString(Duration.class.getName());
-			}
+			TypeDescriptor typeDescriptor = typeUtils.resolveTypeDescriptor(
+					roundEnv.getRootElement(SimpleGenericProperties.class));
+			assertThat(
+					typeDescriptor.getGenerics().keySet().stream().map(Object::toString))
+							.containsOnly("A", "B", "C");
+			assertThat(typeDescriptor.resolveGeneric("A"))
+					.hasToString(String.class.getName());
+			assertThat(typeDescriptor.resolveGeneric("B"))
+					.hasToString(Integer.class.getName());
+			assertThat(typeDescriptor.resolveGeneric("C"))
+					.hasToString(Duration.class.getName());
+
 		});
 	}
 
 	@Test
 	public void resolveTypeDescriptorOnIntermediateClass() throws IOException {
 		process(AbstractIntermediateGenericProperties.class, (roundEnv, typeUtils) -> {
-			for (Element rootElement : roundEnv.getRootElements()) {
-				TypeDescriptor typeDescriptor = typeUtils
-						.resolveTypeDescriptor((TypeElement) rootElement);
-				assertThat(typeDescriptor.getGenerics().keySet().stream()
-						.map(Object::toString)).containsOnly("A", "B", "C");
-				assertThat(typeDescriptor.resolveGeneric("A"))
-						.hasToString(String.class.getName());
-				assertThat(typeDescriptor.resolveGeneric("B"))
-						.hasToString(Integer.class.getName());
-				assertThat(typeDescriptor.resolveGeneric("C")).hasToString("C");
-			}
+			TypeDescriptor typeDescriptor = typeUtils.resolveTypeDescriptor(
+					roundEnv.getRootElement(AbstractIntermediateGenericProperties.class));
+			assertThat(
+					typeDescriptor.getGenerics().keySet().stream().map(Object::toString))
+							.containsOnly("A", "B", "C");
+			assertThat(typeDescriptor.resolveGeneric("A"))
+					.hasToString(String.class.getName());
+			assertThat(typeDescriptor.resolveGeneric("B"))
+					.hasToString(Integer.class.getName());
+			assertThat(typeDescriptor.resolveGeneric("C")).hasToString("C");
 		});
 	}
 
 	@Test
 	public void resolveTypeDescriptorWithOnlyGenerics() throws IOException {
 		process(AbstractGenericProperties.class, (roundEnv, typeUtils) -> {
-			for (Element rootElement : roundEnv.getRootElements()) {
-				TypeDescriptor typeDescriptor = typeUtils
-						.resolveTypeDescriptor((TypeElement) rootElement);
-				assertThat(typeDescriptor.getGenerics().keySet().stream()
-						.map(Object::toString)).containsOnly("A", "B", "C");
+			TypeDescriptor typeDescriptor = typeUtils.resolveTypeDescriptor(
+					roundEnv.getRootElement(AbstractGenericProperties.class));
+			assertThat(
+					typeDescriptor.getGenerics().keySet().stream().map(Object::toString))
+							.containsOnly("A", "B", "C");
 
-			}
 		});
 	}
 
 	private void process(Class<?> target,
-			BiConsumer<RoundEnvironment, TypeUtils> consumer) throws IOException {
+			BiConsumer<RoundEnvironmentTester, TypeUtils> consumer) throws IOException {
 		TestableAnnotationProcessor<TypeUtils> processor = new TestableAnnotationProcessor<>(
 				consumer, TypeUtils::new);
 		TestCompiler compiler = new TestCompiler(this.temporaryFolder);

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/test/RoundEnvironmentTester.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2019 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.boot.configurationprocessor.test;
+
+import javax.annotation.processing.RoundEnvironment;
+import javax.lang.model.element.TypeElement;
+
+/**
+ * A tester utility for {@link RoundEnvironment}.
+ *
+ * @author Stephane Nicoll
+ */
+public class RoundEnvironmentTester {
+
+	private final RoundEnvironment roundEnvironment;
+
+	RoundEnvironmentTester(RoundEnvironment roundEnvironment) {
+		this.roundEnvironment = roundEnvironment;
+	}
+
+	/**
+	 * Return the root {@link TypeElement} for the specified {@code type}.
+	 * @param type the type of the class
+	 * @return the {@link TypeElement}
+	 */
+	public TypeElement getRootElement(Class<?> type) {
+		return (TypeElement) this.roundEnvironment.getRootElements().stream()
+				.filter((element) -> element.toString().equals(type.getName()))
+				.findFirst()
+				.orElseThrow(() -> new IllegalStateException("No element found for "
+						+ type
+						+ " make sure it is included in the list of classes to compile"));
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/test/TestableAnnotationProcessor.java

@@ -39,13 +39,13 @@ import javax.lang.model.element.TypeElement;
 @SupportedSourceVersion(SourceVersion.RELEASE_8)
 public class TestableAnnotationProcessor<T> extends AbstractProcessor {
 
-	private final BiConsumer<RoundEnvironment, T> consumer;
+	private final BiConsumer<RoundEnvironmentTester, T> consumer;
 
 	private final Function<ProcessingEnvironment, T> factory;
 
 	private T target;
 
-	public TestableAnnotationProcessor(BiConsumer<RoundEnvironment, T> consumer,
+	public TestableAnnotationProcessor(BiConsumer<RoundEnvironmentTester, T> consumer,
 			Function<ProcessingEnvironment, T> factory) {
 		this.consumer = consumer;
 		this.factory = factory;
@@ -59,7 +59,11 @@ public class TestableAnnotationProcessor<T> extends AbstractProcessor {
 	@Override
 	public boolean process(Set<? extends TypeElement> annotations,
 			RoundEnvironment roundEnv) {
-		this.consumer.accept(roundEnv, this.target);
+		RoundEnvironmentTester tester = new RoundEnvironmentTester(roundEnv);
+		if (!roundEnv.getRootElements().isEmpty()) {
+			this.consumer.accept(tester, this.target);
+			return true;
+		}
 		return false;
 	}