Raise minimum supported version of JUnit to 6.0

Closes gh-989

Author: wilkinsona

docs/src/docs/asciidoc/getting-started.adoc

@@ -203,29 +203,29 @@ It then produces documentation snippets for the request and the resulting respon
 ==== Setting up Your Tests
 
 Exactly how you set up your tests depends on the test framework that you use.
-Spring REST Docs provides first-class support for JUnit 5.
+Spring REST Docs provides first-class support for JUnit 6.
 Other frameworks, such as TestNG, are also supported, although slightly more setup is required.
 
 
 
-[[getting-started-documentation-snippets-setup-junit-5]]
-===== Setting up Your JUnit 5 Tests
+[[getting-started-documentation-snippets-setup-junit]]
+===== Setting up Your JUnit 6 Tests
 
-When using JUnit 5, the first step in generating documentation snippets is to apply the `RestDocumentationExtension` to your test class.
+When using JUnit 6, the first step in generating documentation snippets is to apply the `RestDocumentationExtension` to your test class.
 The following example shows how to do so:
 
 [source,java,indent=0]
 ----
 @ExtendWith(RestDocumentationExtension.class)
-public class JUnit5ExampleTests {
+public class JUnit6ExampleTests {
 ----
 
 When testing a typical Spring application, you should also apply the `SpringExtension`:
 
 [source,java,indent=0]
 ----
 @ExtendWith({RestDocumentationExtension.class, SpringExtension.class})
-public class JUnit5ExampleTests {
+public class JUnit6ExampleTests {
 ----
 
 The `RestDocumentationExtension` is automatically configured with an output directory based on your project's build tool:
@@ -241,12 +241,12 @@ The `RestDocumentationExtension` is automatically configured with an output dire
 | `build/generated-snippets`
 |===
 
-If you are using JUnit 5.1, you can override the default by registering the extension as a field in your test class and providing an output directory when creating it.
+You can override the default by registering the extension as a field in your test class and providing an output directory when creating it.
 The following example shows how to do so:
 
 [source,java,indent=0]
 ----
-public class JUnit5ExampleTests {
+public class JUnit6ExampleTests {
 
 	@RegisterExtension
 	final RestDocumentationExtension restDocumentation = new RestDocumentationExtension ("custom");

spring-restdocs-core/src/main/java/org/springframework/restdocs/RestDocumentationExtension.java

@@ -83,7 +83,7 @@ private boolean isTestMethodContext(ExtensionContext context) {
 	private ManualRestDocumentation getDelegate(ExtensionContext context) {
 		Namespace namespace = Namespace.create(getClass(), context.getUniqueId());
 		return context.getStore(namespace)
-			.getOrComputeIfAbsent(ManualRestDocumentation.class, this::createManualRestDocumentation,
+			.computeIfAbsent(ManualRestDocumentation.class, this::createManualRestDocumentation,
 					ManualRestDocumentation.class);
 	}
 

spring-restdocs-core/src/testFixtures/java/org/springframework/restdocs/testfixtures/jupiter/OutputCaptureExtension.java

@@ -102,7 +102,7 @@ public Object resolveParameter(ParameterContext parameterContext, ExtensionConte
 	}
 
 	private OutputCapture getOutputCapture(ExtensionContext context) {
-		return getStore(context).getOrComputeIfAbsent(OutputCapture.class);
+		return getStore(context).computeIfAbsent(OutputCapture.class);
 	}
 
 	private Store getStore(ExtensionContext context) {

spring-restdocs-core/src/testFixtures/java/org/springframework/restdocs/testfixtures/jupiter/RenderedSnippetTestExtension.java

@@ -105,14 +105,14 @@ public boolean supportsParameter(ParameterContext parameterContext, ExtensionCon
 		public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) {
 			Class<?> parameterType = parameterContext.getParameter().getType();
 			if (AssertableSnippets.class.equals(parameterType)) {
-				return getStore(extensionContext).getOrComputeIfAbsent(AssertableSnippets.class,
+				return getStore(extensionContext).computeIfAbsent(AssertableSnippets.class,
 						(key) -> new AssertableSnippets(determineOutputDirectory(extensionContext),
 								determineOperationName(extensionContext), this.templateFormat));
 			}
 			if (TemplateFormat.class.equals(parameterType)) {
 				return this.templateFormat;
 			}
-			return getStore(extensionContext).getOrComputeIfAbsent(OperationBuilder.class, (key) -> {
+			return getStore(extensionContext).computeIfAbsent(OperationBuilder.class, (key) -> {
 				OperationBuilder operationBuilder = new OperationBuilder(determineOutputDirectory(extensionContext),
 						determineOperationName(extensionContext), this.templateFormat);
 				AnnotationUtils.findAnnotation(extensionContext.getRequiredTestMethod(), SnippetTemplate.class)

spring-restdocs-core/src/testFixtures/java/org/springframework/restdocs/testfixtures/jupiter/SnippetTestExtension.java

@@ -41,7 +41,7 @@ public boolean supportsParameter(ParameterContext parameterContext, ExtensionCon
 
 	@Override
 	public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) {
-		return getStore(extensionContext).getOrComputeIfAbsent(OperationBuilder.class,
+		return getStore(extensionContext).computeIfAbsent(OperationBuilder.class,
 				(key) -> new OperationBuilder(determineOutputDirectory(extensionContext),
 						determineOperationName(extensionContext)));
 	}

spring-restdocs-platform/build.gradle

@@ -28,7 +28,7 @@ dependencies {
 	api(enforcedPlatform("io.rest-assured:rest-assured-bom:5.5.6"))
 	api(enforcedPlatform("org.assertj:assertj-core:3.27.4"))
 	api(enforcedPlatform("org.mockito:mockito-bom:5.19.0"))
-	api(enforcedPlatform("org.junit:junit-bom:5.13.4"))
+	api(enforcedPlatform("org.junit:junit-bom:6.0.0-RC3"))
 	api(enforcedPlatform("org.springframework:spring-framework-bom:$springFrameworkVersion"))
 	api(enforcedPlatform("tools.jackson:jackson-bom:3.0.0-rc9"))
 }

spring-restdocs-restassured/src/test/java/org/springframework/restdocs/restassured/TomcatServer.java

@@ -53,7 +53,7 @@ class TomcatServer implements BeforeAllCallback, AfterAllCallback {
 	@Override
 	public void beforeAll(ExtensionContext extensionContext) {
 		Store store = extensionContext.getStore(Namespace.create(TomcatServer.class));
-		store.getOrComputeIfAbsent(Tomcat.class, (key) -> {
+		store.computeIfAbsent(Tomcat.class, (key) -> {
 			Tomcat tomcat = new Tomcat();
 			tomcat.getConnector().setPort(0);
 			Context context = tomcat.addContext("/", null);