Polish soft assertions for MockMvc

See gh-26917

Author: sbrannen

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -32,19 +32,21 @@ public interface ResultActions {
 	/**
 	 * Perform an expectation.
 	 *
-	 * <h4>Example</h4>
+	 * <h4>Examples</h4>
+	 *
+	 * <p>You can invoke {@code andExpect()} multiple times.
 	 * <pre class="code">
-	 * static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*
+	 * // static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*
 	 *
 	 * mockMvc.perform(get("/person/1"))
 	 *   .andExpect(status().isOk())
 	 *   .andExpect(content().contentType(MediaType.APPLICATION_JSON))
 	 *   .andExpect(jsonPath("$.person.name").value("Jason"));
 	 * </pre>
 	 *
-	 * <p>Either provide all matchers as a vararg:
+	 * <p>You can provide all matchers as a var-arg list with {@code matchAll()}.
 	 * <pre class="code">
-	 * static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*, ResultMatcher.matchAll
+	 * // static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*, ResultMatcher.matchAll
 	 *
 	 * mockMvc.perform(post("/form"))
 	 *   .andExpect(matchAll(
@@ -57,13 +59,14 @@ public interface ResultActions {
 	 *   );
 	 * </pre>
 	 *
-	 * <p>Or provide all matchers to be evaluated no matter if one of them fail:
+	 * <p>Alternatively, you can provide all matchers to be evaluated using
+	 * <em>soft assertions</em> with {@code matchAllSoftly()}.
 	 * <pre class="code">
-	 * static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*, ResultMatcher.matchAllSoftly
+	 * // static imports: MockMvcRequestBuilders.*, MockMvcResultMatchers.*, ResultMatcher.matchAllSoftly
 	 * mockMvc.perform(post("/form"))
 	 *   .andExpect(matchAllSoftly(
 	 *       status().isOk(),
-	 *       redirectedUrl("/person/1")
+	 *       redirectedUrl("/person/1"))
 	 *   );
 	 * </pre>
 	 */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -16,9 +16,6 @@
 
 package org.springframework.test.web.servlet;
 
-import java.util.ArrayList;
-import java.util.List;
-
 /**
  * A {@code ResultMatcher} matches the result of an executed request against
  * some expectation.
@@ -47,6 +44,7 @@
  *
  * @author Rossen Stoyanchev
  * @author Sam Brannen
+ * @author Michał Rowicki
  * @since 3.2
  */
 @FunctionalInterface
@@ -74,27 +72,29 @@ static ResultMatcher matchAll(ResultMatcher... matchers) {
 	}
 
 	/**
-	 * Static method for matching with an array of result matchers whose assertion failures are caught and stored.
-	 * Only when all of them would be called a {@link AssertionError} be thrown containing the error messages of those
-	 * previously caught assertion failures.
+	 * Static method for matching with an array of result matchers whose assertion
+	 * failures are caught and stored. Once all matchers have been called, if any
+	 * failures occurred, an {@link AssertionError} will be thrown containing the
+	 * error messages of all assertion failures.
 	 * @param matchers the matchers
-	 * @author Michał Rowicki
-	 * @since 5.2
+	 * @since 5.3.10
 	 */
 	static ResultMatcher matchAllSoftly(ResultMatcher... matchers) {
 		return result -> {
-			List<String> failedMessages = new ArrayList<>();
-			for (int i = 0; i < matchers.length; i++) {
-				ResultMatcher matcher = matchers[i];
+			String message = "";
+			for (ResultMatcher matcher : matchers) {
 				try {
 					matcher.match(result);
 				}
-				catch (AssertionError assertionException) {
-					failedMessages.add("[" + i + "] " + assertionException.getMessage());
+				catch (Error | Exception ex) {
+					if (!message.isEmpty()) {
+						message += System.lineSeparator();
+					}
+					message += ex.getMessage();
 				}
 			}
-			if (!failedMessages.isEmpty()) {
-				throw new AssertionError(String.join("\n", failedMessages));
+			if (!message.isEmpty()) {
+				throw new AssertionError(message);
 			}
 		};
 	}

spring-test/src/test/java/org/springframework/test/web/servlet/ResultMatcherTests.java

@@ -16,51 +16,62 @@
 
 package org.springframework.test.web.servlet;
 
-import org.jetbrains.annotations.NotNull;
+import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatNoException;
 
+/**
+ * Unit tests for {@link ResultMatcher}.
+ *
+ * @author Michał Rowicki
+ * @author Sam Brannen
+ * @since 5.3.10
+ */
 class ResultMatcherTests {
 
+	private final StubMvcResult stubMvcResult = new StubMvcResult(null, null, null, null, null, null, null);
+
+
 	@Test
-	void whenProvidedMatcherPassesThenSoftAssertionsAlsoPasses() {
+	void softAssertionsWithNoFailures() {
 		ResultMatcher resultMatcher = ResultMatcher.matchAllSoftly(this::doNothing);
-		StubMvcResult stubMvcResult = new StubMvcResult(null, null, null, null, null, null, null);
 
 		assertThatNoException().isThrownBy(() -> resultMatcher.match(stubMvcResult));
 	}
 
 	@Test
-	void whenOneOfMatcherFailsThenSoftAssertionFailsWithTheVerySameMessage() {
-		String failMessage = "fail message";
-		StubMvcResult stubMvcResult = new StubMvcResult(null, null, null, null, null, null, null);
-		ResultMatcher resultMatcher = ResultMatcher.matchAllSoftly(failMatcher(failMessage));
+	void softAssertionsWithOneFailure() {
+		String failureMessage = "failure message";
+		ResultMatcher resultMatcher = ResultMatcher.matchAllSoftly(failingMatcher(failureMessage));
 
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> resultMatcher.match(stubMvcResult))
-				.withMessage("[0] " + failMessage);
+				.withMessage(failureMessage);
 	}
 
 	@Test
-	void whenMultipleMatchersFailsThenSoftAssertionFailsWithOneErrorWithMessageContainingAllErrorMessagesWithTheSameOrder() {
-		String firstFail = "firstFail";
-		String secondFail = "secondFail";
-		StubMvcResult stubMvcResult = new StubMvcResult(null, null, null, null, null, null, null);
-		ResultMatcher resultMatcher = ResultMatcher.matchAllSoftly(failMatcher(firstFail), failMatcher(secondFail));
+	void softAssertionsWithTwoFailures() {
+		String firstFailure = "firstFailure";
+		String secondFailure = "secondFailure";
+		ResultMatcher resultMatcher = ResultMatcher.matchAllSoftly(failingMatcher(firstFailure), exceptionalMatcher(secondFailure));
 
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> resultMatcher.match(stubMvcResult))
-				.withMessage("[0] " + firstFail + "\n[1] " + secondFail);
+				.withMessage(firstFailure + System.lineSeparator() + secondFailure);
 	}
 
-	@NotNull
-	private ResultMatcher failMatcher(String failMessage) {
+	private ResultMatcher failingMatcher(String failureMessage) {
+		return result -> Assertions.fail(failureMessage);
+	}
+
+	private ResultMatcher exceptionalMatcher(String failureMessage) {
 		return result -> {
-			throw new AssertionError(failMessage);
+			throw new RuntimeException(failureMessage);
 		};
 	}
 
 	void doNothing(MvcResult mvcResult) {}
+
 }