Switch to String#isBlank and String#strip

Since we now have a Java 17 baseline, this commit makes use of
String#isBlank and String#strip (instead of String#trim) throughout the
code base.

Closes #4697

Author: sbrannen

documentation/src/docs/asciidoc/user-guide/running-tests.adoc

@@ -961,18 +961,18 @@ own annotation or other means for users to specify tags.
 Regardless how a tag is specified, the JUnit Platform enforces the following rules:
 
 * A tag must not be `null` or _blank_.
-* A _trimmed_ tag must not contain whitespace.
-* A _trimmed_ tag must not contain ISO control characters.
-* A _trimmed_ tag must not contain any of the following _reserved characters_.
+* A _stripped_ tag must not contain whitespace.
+* A _stripped_ tag must not contain ISO control characters.
+* A _stripped_ tag must not contain any of the following _reserved characters_.
 - `,`: _comma_
 - `(`: _left parenthesis_
 - `)`: _right parenthesis_
 - `&`: _ampersand_
 - `|`: _vertical bar_
 - `!`: _exclamation point_
 
-NOTE: In the above context, "trimmed" means that leading and trailing whitespace
-characters have been removed.
+NOTE: In the above context, "stripped" means that leading and trailing whitespace
+characters have been removed using `java.lang.String.strip()`.
 
 [[running-tests-tag-expressions]]
 ==== Tag Expressions

documentation/src/test/java/example/ParameterizedTestDemo.java

@@ -108,7 +108,7 @@ class NullAndEmptySource_1 {
 		@EmptySource
 		@ValueSource(strings = { " ", "   ", "\t", "\n" })
 		void nullEmptyAndBlankStrings(String text) {
-			assertTrue(text == null || text.trim().isEmpty());
+			assertTrue(text == null || text.isBlank());
 		}
 		// end::NullAndEmptySource_example1[]
 	}
@@ -121,7 +121,7 @@ class NullAndEmptySource_2 {
 		@NullAndEmptySource
 		@ValueSource(strings = { " ", "   ", "\t", "\n" })
 		void nullEmptyAndBlankStrings(String text) {
-			assertTrue(text == null || text.trim().isEmpty());
+			assertTrue(text == null || text.isBlank());
 		}
 		// end::NullAndEmptySource_example2[]
 	}

junit-jupiter-api/src/main/java/org/junit/jupiter/api/AssertLinesMatch.java

@@ -198,13 +198,13 @@ void fail(String format, Object... args) {
 	}
 
 	static boolean isFastForwardLine(String line) {
-		line = line.trim();
+		line = line.strip();
 		return line.length() >= 4 && line.startsWith(">>") && line.endsWith(">>");
 	}
 
 	static int parseFastForwardLimit(String fastForwardLine) {
-		fastForwardLine = fastForwardLine.trim();
-		String text = fastForwardLine.substring(2, fastForwardLine.length() - 2).trim();
+		fastForwardLine = fastForwardLine.strip();
+		String text = fastForwardLine.substring(2, fastForwardLine.length() - 2).strip();
 		try {
 			int limit = Integer.parseInt(text);
 			condition(limit > 0, () -> "fast-forward(%d) limit must be greater than zero".formatted(limit));

junit-jupiter-api/src/main/java/org/junit/jupiter/api/DisplayNameGenerator.java

@@ -391,7 +391,7 @@ private String getSentenceBeginning(Class<?> testClass, List<Class<?>> enclosing
 
 			String sentenceFragment = findAnnotation(testClass, DisplayName.class)//
 					.map(DisplayName::value)//
-					.map(String::trim)//
+					.map(String::strip)//
 					.orElseGet(() -> getSentenceFragment(testClass));
 
 			if (enclosingClass == null || isStatic(testClass)) { // top-level class
@@ -508,7 +508,7 @@ private static Optional<IndicativeSentencesGeneration> findIndicativeSentencesGe
 					.map(sentenceFragment -> {
 						Preconditions.notBlank(sentenceFragment,
 							"@SentenceFragment on [%s] must be declared with a non-blank value.".formatted(element));
-						return sentenceFragment.trim();
+						return sentenceFragment.strip();
 					}) //
 					.orElse(null);
 		}

junit-jupiter-api/src/main/java/org/junit/jupiter/api/Tag.java

@@ -65,7 +65,7 @@
 	/**
 	 * The <em>tag</em>.
 	 *
-	 * <p>Note: the tag will first be {@linkplain String#trim() trimmed}. If the
+	 * <p>Note: the tag will first be {@linkplain String#strip() stripped}. If the
 	 * supplied tag is syntactically invalid after trimming, the error will be
 	 * logged as a warning, and the invalid tag will be effectively ignored. See
 	 * {@linkplain Tag Syntax Rules for Tags}.

junit-jupiter-api/src/main/java/org/junit/jupiter/api/condition/DisabledIfEnvironmentVariableCondition.java

@@ -41,7 +41,7 @@ protected ConditionEvaluationResult getNoDisabledConditionsEncounteredResult() {
 
 	@Override
 	protected ConditionEvaluationResult evaluate(DisabledIfEnvironmentVariable annotation) {
-		String name = annotation.named().trim();
+		String name = annotation.named().strip();
 		String regex = annotation.matches();
 		Preconditions.notBlank(name, () -> "The 'named' attribute must not be blank in " + annotation);
 		Preconditions.notBlank(regex, () -> "The 'matches' attribute must not be blank in " + annotation);

junit-jupiter-api/src/main/java/org/junit/jupiter/api/condition/DisabledIfSystemPropertyCondition.java

@@ -39,7 +39,7 @@ protected ConditionEvaluationResult getNoDisabledConditionsEncounteredResult() {
 
 	@Override
 	protected ConditionEvaluationResult evaluate(DisabledIfSystemProperty annotation) {
-		String name = annotation.named().trim();
+		String name = annotation.named().strip();
 		String regex = annotation.matches();
 		Preconditions.notBlank(name, () -> "The 'named' attribute must not be blank in " + annotation);
 		Preconditions.notBlank(regex, () -> "The 'matches' attribute must not be blank in " + annotation);

junit-jupiter-api/src/main/java/org/junit/jupiter/api/condition/EnabledIfEnvironmentVariableCondition.java

@@ -42,7 +42,7 @@ protected ConditionEvaluationResult getNoDisabledConditionsEncounteredResult() {
 	@Override
 	protected ConditionEvaluationResult evaluate(EnabledIfEnvironmentVariable annotation) {
 
-		String name = annotation.named().trim();
+		String name = annotation.named().strip();
 		String regex = annotation.matches();
 		Preconditions.notBlank(name, () -> "The 'named' attribute must not be blank in " + annotation);
 		Preconditions.notBlank(regex, () -> "The 'matches' attribute must not be blank in " + annotation);

junit-jupiter-api/src/main/java/org/junit/jupiter/api/condition/EnabledIfSystemPropertyCondition.java

@@ -40,7 +40,7 @@ protected ConditionEvaluationResult getNoDisabledConditionsEncounteredResult() {
 	@Override
 	protected ConditionEvaluationResult evaluate(EnabledIfSystemProperty annotation) {
 
-		String name = annotation.named().trim();
+		String name = annotation.named().strip();
 		String regex = annotation.matches();
 		Preconditions.notBlank(name, () -> "The 'named' attribute must not be blank in " + annotation);
 		Preconditions.notBlank(regex, () -> "The 'matches' attribute must not be blank in " + annotation);

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/config/EnumConfigurationParameterConverter.java

@@ -51,7 +51,7 @@ public E get(String key, Function<String, Optional<String>> lookup, E defaultVal
 		if (value.isPresent()) {
 			String constantName = null;
 			try {
-				constantName = value.get().trim().toUpperCase(Locale.ROOT);
+				constantName = value.get().strip().toUpperCase(Locale.ROOT);
 				E result = Enum.valueOf(enumType, constantName);
 				logger.config(() -> "Using %s '%s' set via the '%s' configuration parameter.".formatted(enumDisplayName,
 					result, key));