Prefer modified resources over the originals in TestCompiler

spring-core-test/src/main/java/org/springframework/core/test/tools/DynamicClassLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -121,14 +121,14 @@ protected URL findResource(String name) {
 				return createResourceUrl(name, () -> classBytes);
 			}
 		}
-		ResourceFile resourceFile = this.resourceFiles.get(name);
-		if (resourceFile != null) {
-			return createResourceUrl(resourceFile.getPath(), resourceFile::getBytes);
-		}
 		DynamicResourceFileObject dynamicResourceFile = this.dynamicResourceFiles.get(name);
 		if (dynamicResourceFile != null && dynamicResourceFile.getBytes() != null) {
 			return createResourceUrl(dynamicResourceFile.getName(), dynamicResourceFile::getBytes);
 		}
+		ResourceFile resourceFile = this.resourceFiles.get(name);
+		if (resourceFile != null) {
+			return createResourceUrl(resourceFile.getPath(), resourceFile::getBytes);
+		}
 		return super.findResource(name);
 	}
 

spring-core-test/src/main/java/org/springframework/core/test/tools/DynamicJavaFileManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -70,13 +70,12 @@ public ClassLoader getClassLoader(Location location) {
 	}
 
 	@Override
-	public FileObject getFileForOutput(Location location, String packageName,
-			String relativeName, FileObject sibling) {
-		ResourceFile resourceFile = this.resourceFiles.get(relativeName);
-		if (resourceFile != null) {
-			return new DynamicResourceFileObject(relativeName, resourceFile.getContent());
-		}
-		return this.dynamicResourceFiles.computeIfAbsent(relativeName, DynamicResourceFileObject::new);
+	public FileObject getFileForOutput(Location location, String packageName, String relativeName, FileObject sibling) {
+		return this.dynamicResourceFiles.computeIfAbsent(relativeName, name -> {
+			ResourceFile resourceFile = this.resourceFiles.get(name);
+			return (resourceFile != null) ? new DynamicResourceFileObject(name, resourceFile.getContent())
+					: new DynamicResourceFileObject(name);
+		});
 	}
 
 	@Override

spring-core-test/src/test/java/org/springframework/core/test/tools/DynamicJavaFileManagerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -17,6 +17,7 @@
 package org.springframework.core.test.tools;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.EnumSet;
 
@@ -154,6 +155,23 @@ void getFileForOutputReturnsFile() throws Exception {
 				"META-INF/second.properties");
 	}
 
+	@Test
+	void existingResourceFileCanBeUpdated() throws IOException {
+		try (InputStream input = getResourceOne().openInputStream()) {
+			assertThat(input).hasContent("a");
+		}
+		try (OutputStream output = getResourceOne().openOutputStream()) {
+			output.write('b');
+		}
+		try (InputStream input = getResourceOne().openInputStream()) {
+			assertThat(input).hasContent("b");
+		}
+	}
+
+	private FileObject getResourceOne() {
+		return this.fileManager.getFileForOutput(this.location, "", "com/example/one/resource.one", null);
+	}
+
 	private void writeDummyBytecode(JavaFileObject fileObject) throws IOException {
 		try (OutputStream outputStream = fileObject.openOutputStream()) {
 			StreamUtils.copy(DUMMY_BYTECODE, outputStream);

spring-core-test/src/test/java/org/springframework/core/test/tools/TestCompilerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -16,7 +16,10 @@
 
 package org.springframework.core.test.tools;
 
+import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
@@ -27,6 +30,8 @@
 import javax.annotation.processing.RoundEnvironment;
 import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.lang.model.element.TypeElement;
+import javax.tools.FileObject;
+import javax.tools.StandardLocation;
 
 import com.example.PublicInterface;
 import org.junit.jupiter.api.Test;
@@ -367,6 +372,14 @@ void getResourceForCompiledBytecode() {
 		});
 	}
 
+	@Test
+	void getUpdatedResourceAsStream() {
+		SourceFile sourceFile = SourceFile.of(HELLO_WORLD);
+		TestCompiler.forSystem().withResources(ResourceFile.of("com/example/resource", new byte[] { 'a' }))
+			.withProcessors(new ResourceModifyingProcessor()).compile(sourceFile, compiled -> assertThat(
+				compiled.getClassLoader().getResourceAsStream("com/example/resource")).hasContent("b"));
+	}
+
 	private void assertSuppliesHelloWorld(Compiled compiled) {
 		assertThat(compiled.getInstance(Supplier.class).get()).isEqualTo("Hello World!");
 	}
@@ -392,4 +405,26 @@ public List<TypeElement> getProcessedAnnotations() {
 		}
 	}
 
+	@SupportedAnnotationTypes("java.lang.Deprecated")
+	static class ResourceModifyingProcessor extends AbstractProcessor {
+
+		@Override
+		public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+			if (roundEnv.processingOver()) {
+				try {
+					FileObject resource = this.processingEnv.getFiler()
+						.createResource(StandardLocation.CLASS_OUTPUT, "", "com/example/resource");
+					try (OutputStream output = resource.openOutputStream()) {
+						output.write('b');
+					}
+				}
+				catch (IOException ex) {
+					throw new UncheckedIOException(ex);
+				}
+			}
+			return true;
+		}
+
+	}
+
 }