Add a test to cover the merging of an additional metadata file

This test covers the code path that caused gh-2361 and also checks that,
when an additional metadata file is found, it’s correctly merged with
the other metadata.

Closes gh-2361

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

 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -16,16 +16,23 @@
 
 package org.springframework.boot.configurationprocessor;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileWriter;
 import java.io.IOException;
 
 import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.annotation.processing.SupportedSourceVersion;
 import javax.lang.model.SourceVersion;
 
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 import org.springframework.boot.configurationprocessor.metadata.ConfigurationMetadata;
+import org.springframework.boot.configurationprocessor.metadata.JsonMarshaller;
 import org.springframework.boot.configurationsample.lombok.LombokExplicitProperties;
 import org.springframework.boot.configurationsample.lombok.LombokSimpleDataProperties;
 import org.springframework.boot.configurationsample.lombok.LombokSimpleProperties;
@@ -59,12 +66,20 @@ import static org.springframework.boot.configurationprocessor.ConfigurationMetad
  *
  * @author Stephane Nicoll
  * @author Phillip Webb
+ * @author Andy Wilkinson
  */
 public class ConfigurationMetadataAnnotationProcessorTests {
 
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
+	private TestCompiler compiler;
+
+	@Before
+	public void createCompiler() throws IOException {
+		this.compiler = new TestCompiler(this.temporaryFolder);
+	}
+
 	@Test
 	public void notAnnotated() throws Exception {
 		ConfigurationMetadata metadata = compile(NotAnnotated.class);
@@ -307,6 +322,36 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 		assertSimpleLombokProperties(metadata, LombokExplicitProperties.class, "explicit");
 	}
 
+	@Test
+	public void mergingOfAdditionalMetadata() throws Exception {
+		File metaInfFolder = new File(this.compiler.getOutputLocation(), "META-INF");
+		metaInfFolder.mkdirs();
+		File additionalMetadataFile = new File(metaInfFolder,
+				"additional-spring-configuration-metadata.json");
+		additionalMetadataFile.createNewFile();
+
+		JSONObject property = new JSONObject();
+		property.put("name", "foo");
+		property.put("type", "java.lang.String");
+		property.put("sourceType", AdditionalMetadata.class.getName());
+		JSONArray properties = new JSONArray();
+		properties.put(property);
+		JSONObject additionalMetadata = new JSONObject();
+		additionalMetadata.put("properties", properties);
+		FileWriter writer = new FileWriter(additionalMetadataFile);
+		additionalMetadata.write(writer);
+		writer.flush();
+
+		ConfigurationMetadata metadata = compile(SimpleProperties.class);
+
+		assertThat(metadata, containsProperty("simple.comparator"));
+
+		assertThat(metadata,
+				containsProperty("foo", String.class)
+						.fromSource(AdditionalMetadata.class));
+
+	}
+
 	private void assertSimpleLombokProperties(ConfigurationMetadata metadata,
 			Class<?> source, String prefix) {
 		assertThat(metadata, containsGroup(prefix).fromSource(source));
@@ -324,13 +369,13 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 
 	private ConfigurationMetadata compile(Class<?>... types) throws IOException {
 		TestConfigurationMetadataAnnotationProcessor processor = new TestConfigurationMetadataAnnotationProcessor();
-		new TestCompiler(this.temporaryFolder).getTask(types).call(processor);
+		this.compiler.getTask(types).call(processor);
 		return processor.getMetadata();
 	}
 
 	@SupportedAnnotationTypes({ "*" })
 	@SupportedSourceVersion(SourceVersion.RELEASE_6)
-	private static class TestConfigurationMetadataAnnotationProcessor extends
+	private class TestConfigurationMetadataAnnotationProcessor extends
 			ConfigurationMetadataAnnotationProcessor {
 
 		static final String CONFIGURATION_PROPERTIES_ANNOTATION = "org.springframework.boot.configurationsample.ConfigurationProperties";
@@ -351,7 +396,23 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 
 		@Override
 		protected void writeMetaData(ConfigurationMetadata metadata) {
-			this.metadata = metadata;
+			super.writeMetaData(metadata);
+			try {
+				File metadataFile = new File(
+						ConfigurationMetadataAnnotationProcessorTests.this.compiler
+								.getOutputLocation(),
+						"META-INF/spring-configuration-metadata.json");
+				if (metadataFile.isFile()) {
+					this.metadata = new JsonMarshaller().read(new FileInputStream(
+							metadataFile));
+				}
+				else {
+					this.metadata = metadata;
+				}
+			}
+			catch (IOException e) {
+				throw new RuntimeException("Failed to read metadata from disk", e);
+			}
 		}
 
 		public ConfigurationMetadata getMetadata() {
@@ -360,4 +421,8 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 
 	}
 
+	private static class AdditionalMetadata {
+
+	}
+
 }

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

 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -35,6 +35,7 @@ import org.junit.rules.TemporaryFolder;
  *
  * @author Stephane Nicoll
  * @author Phillip Webb
+ * @author Andy Wilkinson
  */
 public class TestCompiler {
 
@@ -42,6 +43,8 @@ public class TestCompiler {
 
 	private final StandardJavaFileManager fileManager;
 
+	private final File outputLocation;
+
 	public TestCompiler(TemporaryFolder temporaryFolder) throws IOException {
 		this(ToolProvider.getSystemJavaCompiler(), temporaryFolder);
 	}
@@ -50,7 +53,8 @@ public class TestCompiler {
 			throws IOException {
 		this.compiler = compiler;
 		this.fileManager = compiler.getStandardFileManager(null, null, null);
-		Iterable<? extends File> temp = Arrays.asList(temporaryFolder.newFolder());
+		this.outputLocation = temporaryFolder.newFolder();
+		Iterable<? extends File> temp = Arrays.asList(this.outputLocation);
 		this.fileManager.setLocation(StandardLocation.CLASS_OUTPUT, temp);
 		this.fileManager.setLocation(StandardLocation.SOURCE_OUTPUT, temp);
 	}
@@ -61,6 +65,10 @@ public class TestCompiler {
 				null, null, null, javaFileObjects));
 	}
 
+	public File getOutputLocation() {
+		return this.outputLocation;
+	}
+
 	private Iterable<? extends JavaFileObject> getJavaFileObjects(Class<?>... types) {
 		File[] files = new File[types.length];
 		for (int i = 0; i < types.length; i++) {