Nullability refinements on private and static methods

Based on IntelliJ IDEA 2017.3 introspection results.

Issue: SPR-15756

spring-test/src/main/java/org/springframework/mock/web/MockExpressionEvaluator.java

@@ -68,7 +68,6 @@ public class MockExpressionEvaluator extends javax.servlet.jsp.el.ExpressionEval
 	public Object evaluate(String expression, Class expectedType, javax.servlet.jsp.el.VariableResolver variableResolver,
 			javax.servlet.jsp.el.FunctionMapper functionMapper) throws javax.servlet.jsp.el.ELException {
 
-		Assert.isNull(variableResolver, "Custom VariableResolver not supported");
 		return doEvaluate(expression, expectedType, functionMapper);
 	}
 
@@ -76,7 +75,6 @@ public class MockExpressionEvaluator extends javax.servlet.jsp.el.ExpressionEval
 	protected Object doEvaluate(String expression, Class expectedType, javax.servlet.jsp.el.FunctionMapper functionMapper)
 			throws javax.servlet.jsp.el.ELException {
 
-		Assert.isNull(functionMapper, "Custom FunctionMapper not supported");
 		try {
 			return ExpressionEvaluatorManager.evaluate("JSP EL expression", expression, expectedType, this.pageContext);
 		}

spring-test/src/main/java/org/springframework/test/context/jdbc/SqlScriptsTestExecutionListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -30,6 +30,7 @@ import org.springframework.core.io.ByteArrayResource;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.jdbc.datasource.init.ResourceDatabasePopulator;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.TestContext;
 import org.springframework.test.context.jdbc.Sql.ExecutionPhase;
 import org.springframework.test.context.jdbc.SqlConfig.ErrorMode;
@@ -231,6 +232,7 @@ public class SqlScriptsTestExecutionListener extends AbstractTestExecutionListen
 		}
 	}
 
+	@Nullable
 	private DataSource getDataSourceFromTransactionManager(PlatformTransactionManager transactionManager) {
 		try {
 			Method getDataSourceMethod = transactionManager.getClass().getMethod("getDataSource");

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/AbstractExpressionEvaluatingCondition.java

@@ -23,7 +23,6 @@ import java.util.function.Function;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.junit.jupiter.api.extension.ConditionEvaluationResult;
 import org.junit.jupiter.api.extension.ExecutionCondition;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -69,7 +68,6 @@ abstract class AbstractExpressionEvaluatingCondition implements ExecutionConditi
 	/**
 	 * Evaluate the expression configured via the supplied annotation type on
 	 * the {@link AnnotatedElement} for the supplied {@link ExtensionContext}.
-	 *
 	 * @param annotationType the type of annotation to process
 	 * @param expressionExtractor a function that extracts the expression from
 	 * the annotation
@@ -88,6 +86,7 @@ abstract class AbstractExpressionEvaluatingCondition implements ExecutionConditi
 			Function<A, String> expressionExtractor, Function<A, String> reasonExtractor,
 			Function<A, Boolean> loadContextExtractor, boolean enabledOnTrue, ExtensionContext context) {
 
+		Assert.state(context.getElement().isPresent(), "No AnnotatedElement");
 		AnnotatedElement element = context.getElement().get();
 		Optional<A> annotation = findMergedAnnotation(element, annotationType);
 
@@ -100,13 +99,11 @@ abstract class AbstractExpressionEvaluatingCondition implements ExecutionConditi
 			return ConditionEvaluationResult.enabled(reason);
 		}
 
-		// @formatter:off
 		String expression = annotation.map(expressionExtractor).map(String::trim).filter(StringUtils::hasLength)
 				.orElseThrow(() -> new IllegalStateException(String.format(
 						"The expression in @%s on [%s] must not be blank", annotationType.getSimpleName(), element)));
-		// @formatter:on
 
-		boolean loadContext = annotation.map(loadContextExtractor).get();
+		boolean loadContext = loadContextExtractor.apply(annotation.get());
 		boolean evaluatedToTrue = evaluateExpression(expression, loadContext, annotationType, context);
 
 		if (evaluatedToTrue) {
@@ -127,20 +124,21 @@ abstract class AbstractExpressionEvaluatingCondition implements ExecutionConditi
 			if (logger.isDebugEnabled()) {
 				logger.debug(reason);
 			}
-			return (enabledOnTrue ? ConditionEvaluationResult.disabled(reason)
-					: ConditionEvaluationResult.enabled(reason));
+			return (enabledOnTrue ? ConditionEvaluationResult.disabled(reason) :
+					ConditionEvaluationResult.enabled(reason));
 		}
 	}
 
 	private <A extends Annotation> boolean evaluateExpression(String expression, boolean loadContext,
-			Class<A> annotationType, ExtensionContext extensionContext) {
+			Class<A> annotationType, ExtensionContext context) {
 
-		AnnotatedElement element = extensionContext.getElement().get();
+		Assert.state(context.getElement().isPresent(), "No AnnotatedElement");
+		AnnotatedElement element = context.getElement().get();
 		GenericApplicationContext gac = null;
 		ApplicationContext applicationContext;
 
 		if (loadContext) {
-			applicationContext = SpringExtension.getApplicationContext(extensionContext);
+			applicationContext = SpringExtension.getApplicationContext(context);
 		}
 		else {
 			gac = new GenericApplicationContext();
@@ -191,8 +189,9 @@ abstract class AbstractExpressionEvaluatingCondition implements ExecutionConditi
 		}
 	}
 
-	private static <A extends Annotation> Optional<A> findMergedAnnotation(AnnotatedElement element,
-			Class<A> annotationType) {
+	private static <A extends Annotation> Optional<A> findMergedAnnotation(
+			AnnotatedElement element, Class<A> annotationType) {
+
 		return Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(element, annotationType));
 	}
 

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/DisabledIfCondition.java

@@ -20,9 +20,9 @@ import org.junit.jupiter.api.extension.ConditionEvaluationResult;
 import org.junit.jupiter.api.extension.ExtensionContext;
 
 /**
- * {@code DisabledIfCondition} is an {@link ExecutionCondition} that supports the
- * {@link DisabledIf @DisabledIf} annotation when using the <em>Spring TestContext
- * Framework</em> in conjunction with JUnit 5's <em>Jupiter</em> programming model.
+ * {@code DisabledIfCondition} is an {@link org.junit.jupiter.api.extension.ExecutionCondition}
+ * that supports the {@link DisabledIf @DisabledIf} annotation when using the <em>Spring
+ * TestContext Framework</em> in conjunction with JUnit 5's <em>Jupiter</em> programming model.
  *
  * <p>Any attempt to use the {@code DisabledIfCondition} without the presence of
  * {@link DisabledIf @DisabledIf} will result in an <em>enabled</em>
@@ -43,8 +43,8 @@ public class DisabledIfCondition extends AbstractExpressionEvaluatingCondition {
 	 */
 	@Override
 	public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext context) {
-		return evaluateAnnotation(DisabledIf.class, DisabledIf::expression, DisabledIf::reason, DisabledIf::loadContext,
-			false, context);
+		return evaluateAnnotation(DisabledIf.class, DisabledIf::expression, DisabledIf::reason,
+				DisabledIf::loadContext, false, context);
 	}
 
 }

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/EnabledIfCondition.java

@@ -20,9 +20,9 @@ import org.junit.jupiter.api.extension.ConditionEvaluationResult;
 import org.junit.jupiter.api.extension.ExtensionContext;
 
 /**
- * {@code EnabledIfCondition} is an {@link ExecutionCondition} that supports the
- * {@link EnabledIf @EnabledIf} annotation when using the <em>Spring TestContext
- * Framework</em> in conjunction with JUnit 5's <em>Jupiter</em> programming model.
+ * {@code EnabledIfCondition} is an {@link org.junit.jupiter.api.extension.ExecutionCondition}
+ * that supports the {@link EnabledIf @EnabledIf} annotation when using the <em>Spring
+ * TestContext Framework</em> in conjunction with JUnit 5's <em>Jupiter</em> programming model.
  *
  * <p>Any attempt to use the {@code EnabledIfCondition} without the presence of
  * {@link EnabledIf @EnabledIf} will result in an <em>enabled</em>
@@ -43,8 +43,8 @@ public class EnabledIfCondition extends AbstractExpressionEvaluatingCondition {
 	 */
 	@Override
 	public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext context) {
-		return evaluateAnnotation(EnabledIf.class, EnabledIf::expression, EnabledIf::reason, EnabledIf::loadContext,
-			true, context);
+		return evaluateAnnotation(EnabledIf.class, EnabledIf::expression, EnabledIf::reason,
+				EnabledIf::loadContext, true, context);
 	}
 
 }

spring-test/src/main/java/org/springframework/test/context/testng/AbstractTestNGSpringContextTests.java

@@ -115,7 +115,6 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 	/**
 	 * Set the {@link ApplicationContext} to be used by this test instance,
 	 * provided via {@link ApplicationContextAware} semantics.
-	 *
 	 * @param applicationContext the ApplicationContext that this test runs in
 	 */
 	@Override
@@ -123,13 +122,11 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 		this.applicationContext = applicationContext;
 	}
 
+
 	/**
 	 * Delegates to the configured {@link TestContextManager} to call
-	 * {@linkplain TestContextManager#beforeTestClass() 'before test class'}
-	 * callbacks.
-	 *
-	 * @throws Exception if a registered TestExecutionListener throws an
-	 * exception
+	 * {@linkplain TestContextManager#beforeTestClass() 'before test class'} callbacks.
+	 * @throws Exception if a registered TestExecutionListener throws an exception
 	 */
 	@BeforeClass(alwaysRun = true)
 	protected void springTestContextBeforeTestClass() throws Exception {
@@ -141,9 +138,7 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 	 * {@linkplain TestContextManager#prepareTestInstance(Object) prepare} this test
 	 * instance prior to execution of any individual tests, for example for
 	 * injecting dependencies, etc.
-	 *
-	 * @throws Exception if a registered TestExecutionListener throws an
-	 * exception
+	 * @throws Exception if a registered TestExecutionListener throws an exception
 	 */
 	@BeforeClass(alwaysRun = true, dependsOnMethods = "springTestContextBeforeTestClass")
 	protected void springTestContextPrepareTestInstance() throws Exception {
@@ -154,7 +149,6 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 	 * Delegates to the configured {@link TestContextManager} to
 	 * {@linkplain TestContextManager#beforeTestMethod(Object,Method) pre-process}
 	 * the test method before the actual test is executed.
-	 *
 	 * @param testMethod the test method which is about to be executed
 	 * @throws Exception allows all exceptions to propagate
 	 */
@@ -167,7 +161,6 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 	 * Delegates to the {@linkplain IHookCallBack#runTestMethod(ITestResult) test
 	 * method} in the supplied {@code callback} to execute the actual test
 	 * and then tracks the exception thrown during test execution, if any.
-	 *
 	 * @see org.testng.IHookable#run(IHookCallBack, ITestResult)
 	 */
 	@Override
@@ -224,15 +217,14 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 	/**
 	 * Delegates to the configured {@link TestContextManager} to call
 	 * {@linkplain TestContextManager#afterTestClass() 'after test class'} callbacks.
-	 *
-	 * @throws Exception if a registered TestExecutionListener throws an
-	 * exception
+	 * @throws Exception if a registered TestExecutionListener throws an exception
 	 */
 	@AfterClass(alwaysRun = true)
 	protected void springTestContextAfterTestClass() throws Exception {
 		this.testContextManager.afterTestClass();
 	}
 
+
 	private Throwable getTestResultException(ITestResult testResult) {
 		Throwable testResultException = testResult.getThrowable();
 		if (testResultException instanceof InvocationTargetException) {
@@ -241,12 +233,10 @@ public abstract class AbstractTestNGSpringContextTests implements IHookable, App
 		return testResultException;
 	}
 
-	@Nullable
 	private RuntimeException throwAsUncheckedException(Throwable t) {
 		throwAs(t);
-
 		// Appeasing the compiler: the following line will never be executed.
-		return null;
+		throw new IllegalStateException(t);
 	}
 
 	@SuppressWarnings("unchecked")

spring-test/src/main/java/org/springframework/test/web/servlet/MockMvc.java

@@ -95,7 +95,7 @@ public final class MockMvc {
 	 * A default request builder merged into every performed request.
 	 * @see org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder#defaultRequest(RequestBuilder)
 	 */
-	void setDefaultRequest(RequestBuilder requestBuilder) {
+	void setDefaultRequest(@Nullable RequestBuilder requestBuilder) {
 		this.defaultRequestBuilder = requestBuilder;
 	}
 
@@ -104,7 +104,7 @@ public final class MockMvc {
 	 * @see org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder#alwaysExpect(ResultMatcher)
 	 */
 	void setGlobalResultMatchers(List<ResultMatcher> resultMatchers) {
-		Assert.notNull(resultMatchers, "resultMatchers is required");
+		Assert.notNull(resultMatchers, "ResultMatcher List is required");
 		this.defaultResultMatchers = resultMatchers;
 	}
 
@@ -113,7 +113,7 @@ public final class MockMvc {
 	 * @see org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder#alwaysDo(ResultHandler)
 	 */
 	void setGlobalResultHandlers(List<ResultHandler> resultHandlers) {
-		Assert.notNull(resultHandlers, "resultHandlers is required");
+		Assert.notNull(resultHandlers, "ResultHandler List is required");
 		this.defaultResultHandlers = resultHandlers;
 	}
 

spring-test/src/main/java/org/springframework/test/web/servlet/MockMvcBuilderSupport.java

@@ -41,7 +41,7 @@ import org.springframework.web.context.WebApplicationContext;
 public abstract class MockMvcBuilderSupport {
 
 	protected final MockMvc createMockMvc(Filter[] filters, MockServletConfig servletConfig,
-			WebApplicationContext webAppContext, RequestBuilder defaultRequestBuilder,
+			WebApplicationContext webAppContext, @Nullable RequestBuilder defaultRequestBuilder,
 			List<ResultMatcher> globalResultMatchers, List<ResultHandler> globalResultHandlers,
 			@Nullable List<DispatcherServletCustomizer> dispatcherServletCustomizers) {