Add Consumer methods to WebTestClient assertion classes

Issue: SPR-16574

Author: rstoyanchev

spring-test/src/main/java/org/springframework/test/util/JsonPathExpectationsHelper.java

@@ -20,19 +20,15 @@
 import java.util.Map;
 
 import com.jayway.jsonpath.JsonPath;
+import org.hamcrest.CoreMatchers;
 import org.hamcrest.Matcher;
+import org.hamcrest.MatcherAssert;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.core.IsInstanceOf.instanceOf;
-import static org.springframework.test.util.AssertionErrors.assertEquals;
-import static org.springframework.test.util.AssertionErrors.assertTrue;
-import static org.springframework.test.util.AssertionErrors.fail;
-
 /**
  * A helper class for applying assertions via JSON path expressions.
  *
@@ -74,7 +70,7 @@ public JsonPathExpectationsHelper(String expression, Object... args) {
 	@SuppressWarnings("unchecked")
 	public <T> void assertValue(String content, Matcher<T> matcher) {
 		T value = (T) evaluateJsonPath(content);
-		assertThat("JSON path \"" + this.expression + "\"", value, matcher);
+		MatcherAssert.assertThat("JSON path \"" + this.expression + "\"", value, matcher);
 	}
 
 	/**
@@ -89,7 +85,7 @@ public <T> void assertValue(String content, Matcher<T> matcher) {
 	@SuppressWarnings("unchecked")
 	public <T> void assertValue(String content, Matcher<T> matcher, Class<T> targetType) {
 		T value = (T) evaluateJsonPath(content, targetType);
-		assertThat("JSON path \"" + this.expression + "\"", value, matcher);
+		MatcherAssert.assertThat("JSON path \"" + this.expression + "\"", value, matcher);
 	}
 
 	/**
@@ -104,10 +100,11 @@ public void assertValue(String content, @Nullable Object expectedValue) {
 			@SuppressWarnings("rawtypes")
 			List actualValueList = (List) actualValue;
 			if (actualValueList.isEmpty()) {
-				fail("No matching value at JSON path \"" + this.expression + "\"");
+				AssertionErrors.fail("No matching value at JSON path \"" + this.expression + "\"");
 			}
 			if (actualValueList.size() != 1) {
-				fail("Got a list of values " + actualValue + " instead of the expected single value " + expectedValue);
+				AssertionErrors.fail("Got a list of values " + actualValue +
+						" instead of the expected single value " + expectedValue);
 			}
 			actualValue = actualValueList.get(0);
 		}
@@ -116,7 +113,7 @@ else if (actualValue != null && expectedValue != null) {
 				actualValue = evaluateJsonPath(content, expectedValue.getClass());
 			}
 		}
-		assertEquals("JSON path \"" + this.expression + "\"", expectedValue, actualValue);
+		AssertionErrors.assertEquals("JSON path \"" + this.expression + "\"", expectedValue, actualValue);
 	}
 
 	/**
@@ -127,7 +124,7 @@ else if (actualValue != null && expectedValue != null) {
 	 */
 	public void assertValueIsString(String content) {
 		Object value = assertExistsAndReturn(content);
-		assertThat(failureReason("a string", value), value, instanceOf(String.class));
+		MatcherAssert.assertThat(failureReason("a string", value), value, CoreMatchers.instanceOf(String.class));
 	}
 
 	/**
@@ -138,7 +135,7 @@ public void assertValueIsString(String content) {
 	 */
 	public void assertValueIsBoolean(String content) {
 		Object value = assertExistsAndReturn(content);
-		assertThat(failureReason("a boolean", value), value, instanceOf(Boolean.class));
+		MatcherAssert.assertThat(failureReason("a boolean", value), value, CoreMatchers.instanceOf(Boolean.class));
 	}
 
 	/**
@@ -149,7 +146,7 @@ public void assertValueIsBoolean(String content) {
 	 */
 	public void assertValueIsNumber(String content) {
 		Object value = assertExistsAndReturn(content);
-		assertThat(failureReason("a number", value), value, instanceOf(Number.class));
+		MatcherAssert.assertThat(failureReason("a number", value), value, CoreMatchers.instanceOf(Number.class));
 	}
 
 	/**
@@ -159,7 +156,7 @@ public void assertValueIsNumber(String content) {
 	 */
 	public void assertValueIsArray(String content) {
 		Object value = assertExistsAndReturn(content);
-		assertThat(failureReason("an array", value), value, instanceOf(List.class));
+		MatcherAssert.assertThat(failureReason("an array", value), value, CoreMatchers.instanceOf(List.class));
 	}
 
 	/**
@@ -170,7 +167,7 @@ public void assertValueIsArray(String content) {
 	 */
 	public void assertValueIsMap(String content) {
 		Object value = assertExistsAndReturn(content);
-		assertThat(failureReason("a map", value), value, instanceOf(Map.class));
+		MatcherAssert.assertThat(failureReason("a map", value), value, CoreMatchers.instanceOf(Map.class));
 	}
 
 	/**
@@ -204,10 +201,10 @@ public void doesNotExist(String content) {
 		}
 		String reason = failureReason("no value", value);
 		if (pathIsIndefinite() && value instanceof List) {
-			assertTrue(reason, ((List<?>) value).isEmpty());
+			AssertionErrors.assertTrue(reason, ((List<?>) value).isEmpty());
 		}
 		else {
-			assertTrue(reason, (value == null));
+			AssertionErrors.assertTrue(reason, (value == null));
 		}
 	}
 
@@ -220,7 +217,7 @@ public void doesNotExist(String content) {
 	 */
 	public void assertValueIsEmpty(String content) {
 		Object value = evaluateJsonPath(content);
-		assertTrue(failureReason("an empty value", value), ObjectUtils.isEmpty(value));
+		AssertionErrors.assertTrue(failureReason("an empty value", value), ObjectUtils.isEmpty(value));
 	}
 
 	/**
@@ -232,7 +229,7 @@ public void assertValueIsEmpty(String content) {
 	 */
 	public void assertValueIsNotEmpty(String content) {
 		Object value = evaluateJsonPath(content);
-		assertTrue(failureReason("a non-empty value", value), !ObjectUtils.isEmpty(value));
+		AssertionErrors.assertTrue(failureReason("a non-empty value", value), !ObjectUtils.isEmpty(value));
 	}
 
 	/**
@@ -247,7 +244,8 @@ public void assertValueIsNotEmpty(String content) {
 	public void hasJsonPath(String content) {
 		Object value = evaluateJsonPath(content);
 		if (pathIsIndefinite() && value instanceof List) {
-			assertTrue("No values for JSON path \"" + this.expression + "\"", !((List<?>) value).isEmpty());
+			String message = "No values for JSON path \"" + this.expression + "\"";
+			AssertionErrors.assertTrue(message, !((List<?>) value).isEmpty());
 		}
 	}
 
@@ -270,10 +268,10 @@ public void doesNotHaveJsonPath(String content) {
 			return;
 		}
 		if (pathIsIndefinite() && value instanceof List) {
-			assertTrue(failureReason("no values", value), ((List<?>) value).isEmpty());
+			AssertionErrors.assertTrue(failureReason("no values", value), ((List<?>) value).isEmpty());
 		}
 		else {
-			fail(failureReason("no value", value));
+			AssertionErrors.fail(failureReason("no value", value));
 		}
 	}
 
@@ -282,18 +280,31 @@ private String failureReason(String expectedDescription, @Nullable Object value)
 				ObjectUtils.nullSafeToString(StringUtils.quoteIfString(value)));
 	}
 
+	/**
+	 * Evaluate the JSON path and return the resulting value.
+	 * @param content the content to evaluate against
+	 * @return the result of the evaluation
+	 * @throws AssertionError if the evaluation fails
+	 */
 	@Nullable
-	private Object evaluateJsonPath(String content) {
+	public Object evaluateJsonPath(String content) {
 		try {
 			return this.jsonPath.read(content);
 		}
 		catch (Throwable ex) {
-			String message = "No value at JSON path \"" + this.expression + "\"";
-			throw new AssertionError(message, ex);
+			throw new AssertionError("No value at JSON path \"" + this.expression + "\"", ex);
 		}
 	}
 
-	private Object evaluateJsonPath(String content, Class<?> targetType) {
+	/**
+	 * Variant of {@link #evaluateJsonPath(String)} with a target type.
+	 * This can be useful for matching numbers reliably for example coercing an
+	 * integer into a double.
+	 * @param content the content to evaluate against
+	 * @return the result of the evaluation
+	 * @throws AssertionError if the evaluation fails
+	 */
+	public Object evaluateJsonPath(String content, Class<?> targetType) {
 		try {
 			return JsonPath.parse(content).read(this.expression, targetType);
 		}
@@ -307,9 +318,9 @@ private Object evaluateJsonPath(String content, Class<?> targetType) {
 	private Object assertExistsAndReturn(String content) {
 		Object value = evaluateJsonPath(content);
 		String reason = "No value at JSON path \"" + this.expression + "\"";
-		assertTrue(reason, value != null);
+		AssertionErrors.assertTrue(reason, value != null);
 		if (pathIsIndefinite() && value instanceof List) {
-			assertTrue(reason, !((List<?>) value).isEmpty());
+			AssertionErrors.assertTrue(reason, !((List<?>) value).isEmpty());
 		}
 		return value;
 	}