Simplify assertions within MockMvc internals

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

@@ -31,6 +31,7 @@ import org.springframework.test.web.servlet.ResultMatcher;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.springframework.test.util.AssertionErrors.assertEquals;
+import static org.springframework.test.util.AssertionErrors.assertNotNull;
 import static org.springframework.test.util.AssertionErrors.assertTrue;
 
 /**
@@ -77,10 +78,8 @@ public class ContentResultMatchers {
 	public ResultMatcher contentType(MediaType contentType) {
 		return result -> {
 			String actual = result.getResponse().getContentType();
-			assertTrue("Content type not set", actual != null);
-			if (actual != null) {
-				assertEquals("Content type", contentType, MediaType.parseMediaType(actual));
-			}
+			assertNotNull("Content type not set", actual);
+			assertEquals("Content type", contentType, MediaType.parseMediaType(actual));
 		};
 	}
 
@@ -99,12 +98,10 @@ public class ContentResultMatchers {
 	public ResultMatcher contentTypeCompatibleWith(MediaType contentType) {
 		return result -> {
 			String actual = result.getResponse().getContentType();
-			assertTrue("Content type not set", actual != null);
-			if (actual != null) {
-				MediaType actualContentType = MediaType.parseMediaType(actual);
-				assertTrue("Content type [" + actual + "] is not compatible with [" + contentType + "]",
-						actualContentType.isCompatibleWith(contentType));
-			}
+			assertNotNull("Content type not set", actual);
+			MediaType actualContentType = MediaType.parseMediaType(actual);
+			assertTrue("Content type [" + actual + "] is not compatible with [" + contentType + "]",
+					actualContentType.isCompatibleWith(contentType));
 		};
 	}
 

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

@@ -20,12 +20,12 @@ import javax.servlet.http.Cookie;
 
 import org.hamcrest.Matcher;
 
-import org.springframework.test.util.AssertionErrors;
 import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.ResultMatcher;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.springframework.test.util.AssertionErrors.assertEquals;
+import static org.springframework.test.util.AssertionErrors.assertNotNull;
 import static org.springframework.test.util.AssertionErrors.assertTrue;
 
 /**
@@ -208,9 +208,7 @@ public class CookieResultMatchers {
 
 	private static Cookie getCookie(MvcResult result, String name) {
 		Cookie cookie = result.getResponse().getCookie(name);
-		if (cookie == null) {
-			AssertionErrors.fail("No cookie with name '" + name + "'");
-		}
+		assertNotNull("No cookie with name '" + name + "'", cookie);
 		return cookie;
 	}
 

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

@@ -22,7 +22,7 @@ import org.springframework.test.web.servlet.ResultMatcher;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.springframework.test.util.AssertionErrors.assertEquals;
-import static org.springframework.test.util.AssertionErrors.assertTrue;
+import static org.springframework.test.util.AssertionErrors.assertNotNull;
 
 /**
  * Factory for "output" flash attribute assertions.
@@ -64,7 +64,7 @@ public class FlashAttributeResultMatchers {
 	public <T> ResultMatcher attributeExists(String... names) {
 		return result -> {
 			for (String name : names) {
-				assertTrue("Flash attribute '" + name + "' does not exist", result.getFlashMap().get(name) != null);
+				assertNotNull("Flash attribute '" + name + "' does not exist", result.getFlashMap().get(name));
 			}
 		};
 	}

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

@@ -31,6 +31,7 @@ import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandl
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.springframework.test.util.AssertionErrors.assertEquals;
+import static org.springframework.test.util.AssertionErrors.assertNotNull;
 import static org.springframework.test.util.AssertionErrors.assertTrue;
 import static org.springframework.test.util.AssertionErrors.fail;
 
@@ -65,7 +66,7 @@ public class HandlerResultMatchers {
 	public ResultMatcher handlerType(Class<?> type) {
 		return result -> {
 			Object handler = result.getHandler();
-			assertTrue("No handler", handler != null);
+			assertNotNull("No handler", handler);
 			if (handler != null) {
 				Class<?> actual = handler.getClass();
 				if (HandlerMethod.class.isInstance(handler)) {
@@ -148,10 +149,7 @@ public class HandlerResultMatchers {
 
 	private static HandlerMethod getHandlerMethod(MvcResult result) {
 		Object handler = result.getHandler();
-		assertTrue("No handler", handler != null);
-		if (!(handler instanceof HandlerMethod)) {
-			fail("Not a HandlerMethod: " + handler);
-		}
+		assertTrue("Not a HandlerMethod: " + handler, handler instanceof HandlerMethod);
 		return (HandlerMethod) handler;
 	}
 

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

@@ -28,8 +28,8 @@ import org.springframework.web.servlet.ModelAndView;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.springframework.test.util.AssertionErrors.assertEquals;
+import static org.springframework.test.util.AssertionErrors.assertNotNull;
 import static org.springframework.test.util.AssertionErrors.assertTrue;
-import static org.springframework.test.util.AssertionErrors.fail;
 
 /**
  * Factory for assertions on the model.
@@ -38,6 +38,7 @@ import static org.springframework.test.util.AssertionErrors.fail;
  * {@link MockMvcResultMatchers#model}.
  *
  * @author Rossen Stoyanchev
+ * @author Sam Brannen
  * @since 3.2
  */
 public class ModelResultMatchers {
@@ -78,7 +79,7 @@ public class ModelResultMatchers {
 		return result -> {
 			ModelAndView mav = getModelAndView(result);
 			for (String name : names) {
-				assertTrue("Model attribute '" + name + "' does not exist", mav.getModel().get(name) != null);
+				assertNotNull("Model attribute '" + name + "' does not exist", mav.getModel().get(name));
 			}
 		};
 	}
@@ -159,11 +160,9 @@ public class ModelResultMatchers {
 			BindingResult result = getBindingResult(mav, name);
 			assertTrue("No errors for attribute '" + name + "'", result.hasErrors());
 			FieldError fieldError = result.getFieldError(fieldName);
-			if (fieldError == null) {
-				fail("No errors for field '" + fieldName + "' of attribute '" + name + "'");
-			}
+			assertNotNull("No errors for field '" + fieldName + "' of attribute '" + name + "'", fieldError);
 			String code = fieldError.getCode();
-			assertTrue("Expected error code '" + error + "' but got '" + code + "'", error.equals(code));
+			assertEquals("Field error code", error, code);
 		};
 	}
 
@@ -177,11 +176,9 @@ public class ModelResultMatchers {
 		return mvcResult -> {
 			ModelAndView mav = getModelAndView(mvcResult);
 			BindingResult result = getBindingResult(mav, name);
-			assertTrue("No errors for attribute: [" + name + "]", result.hasErrors());
+			assertTrue("No errors for attribute '" + name + "'", result.hasErrors());
 			FieldError fieldError = result.getFieldError(fieldName);
-			if (fieldError == null) {
-				fail("No errors for field '" + fieldName + "' of attribute '" + name + "'");
-			}
+			assertNotNull("No errors for field '" + fieldName + "' of attribute '" + name + "'", fieldError);
 			String code = fieldError.getCode();
 			assertThat("Field name '" + fieldName + "' of attribute '" + name + "'", code, matcher);
 		};
@@ -239,17 +236,13 @@ public class ModelResultMatchers {
 
 	private ModelAndView getModelAndView(MvcResult mvcResult) {
 		ModelAndView mav = mvcResult.getModelAndView();
-		if (mav == null) {
-			fail("No ModelAndView found");
-		}
+		assertNotNull("No ModelAndView found", mav);
 		return mav;
 	}
 
 	private BindingResult getBindingResult(ModelAndView mav, String name) {
 		BindingResult result = (BindingResult) mav.getModel().get(BindingResult.MODEL_KEY_PREFIX + name);
-		if (result == null) {
-			fail("No BindingResult for attribute: " + name);
-		}
+		assertNotNull("No BindingResult for attribute: " + name, result);
 		return result;
 	}