Make quote character in @CsvSource configurable

Prior to this commit, the quote character for quoted strings in
@CsvSource was hard coded to a single quote (') and could not be
changed; however, with the recently added support for text blocks, it
may be desirable to change the quote character to something else.

This commit introduces a new quoteCharacter attribute in @CsvSource
that allows the user to change the quote character. The quoteCharacter
defaults to a single quote for backward compatibility.

Closes junit-team#2735

documentation/src/docs/asciidoc/release-notes/release-notes-5.8.2.adoc

@@ -39,7 +39,9 @@ GitHub.
 
 ==== New Features and Improvements
 
-* ❓
+* The quote character for _quoted strings_ in `@CsvSource` is now configurable via the new
+  `quoteCharacter` attribute, which defaults to a single quote (`'`) for backward
+  compatibility.
 
 
 [[release-notes-5.8.2-junit-vintage]]

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

@@ -1363,13 +1363,14 @@ The default delimiter is a comma (`,`), but you can use another character by set
 `String` delimiter instead of a single character. However, both delimiter attributes
 cannot be set simultaneously.
 
-`@CsvSource` uses a single quote `'` as its quote character. See the `'lemon, lime'` value
-in the example above and in the table below. An empty, quoted value `''` results in an
-empty `String` unless the `emptyValue` attribute is set; whereas, an entirely _empty_
-value is interpreted as a `null` reference. By specifying one or more `nullValues`, a
-custom value can be interpreted as a `null` reference (see the `NIL` example in the table
-below). An `ArgumentConversionException` is thrown if the target type of a `null`
-reference is a primitive type.
+By default, `@CsvSource` uses a single quote `'` as its quote character, but this can be
+changed via the `quoteCharacter` attribute. See the `'lemon, lime'` value in the example
+above and in the table below. An empty, quoted value `''` results in an empty `String`
+unless the `emptyValue` attribute is set; whereas, an entirely _empty_ value is
+interpreted as a `null` reference. By specifying one or more `nullValues`, a custom value
+can be interpreted as a `null` reference (see the `NIL` example in the table below). An
+`ArgumentConversionException` is thrown if the target type of a `null` reference is a
+primitive type.
 
 NOTE: An _unquoted_ empty value will always be converted to a `null` reference regardless
 of any custom values configured via the `nullValues` attribute.

junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/CsvParserFactory.java

@@ -24,15 +24,14 @@ class CsvParserFactory {
 
 	private static final String DEFAULT_DELIMITER = ",";
 	private static final String LINE_SEPARATOR = "\n";
-	private static final char SINGLE_QUOTE = '\'';
 	private static final char DOUBLE_QUOTE = '"';
 	private static final char EMPTY_CHAR = '\0';
 	private static final boolean COMMENT_PROCESSING_FOR_CSV_SOURCE = false;
 	private static final boolean COMMENT_PROCESSING_FOR_CSV_FILE_SOURCE = true;
 
 	static CsvParser createParserFor(CsvSource annotation) {
 		String delimiter = selectDelimiter(annotation, annotation.delimiter(), annotation.delimiterString());
-		return createParser(delimiter, LINE_SEPARATOR, SINGLE_QUOTE, annotation.emptyValue(),
+		return createParser(delimiter, LINE_SEPARATOR, annotation.quoteCharacter(), annotation.emptyValue(),
 			annotation.maxCharsPerColumn(), COMMENT_PROCESSING_FOR_CSV_SOURCE,
 			annotation.ignoreLeadingAndTrailingWhitespace());
 	}

junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/CsvSource.java

@@ -32,8 +32,9 @@
  * <p>The column delimiter (defaults to comma) can be customized with either
  * {@link #delimiter} or {@link #delimiterString}.
  *
- * <p>{@code @CsvSource} uses a single quote ({@code '}) as its quote character.
- * See the {@code 'lemon, lime'} examples in the documentation for the {@link #value}
+ * <p>By default, {@code @CsvSource} uses a single quote ({@code '}) as its quote
+ * character, but this can be changed via {@link #quoteCharacter}. See the
+ * {@code 'lemon, lime'} examples in the documentation for the {@link #value}
  * and {@link #textBlock} attributes. An empty, quoted value ({@code ''}) results
  * in an empty {@link String} unless the {@link #emptyValue} attribute is set;
  * whereas, an entirely <em>empty</em> value is interpreted as a {@code null} reference.
@@ -126,6 +127,21 @@
 	@API(status = EXPERIMENTAL, since = "5.8.1")
 	String textBlock() default "";
 
+	/**
+	 * The quote character to use for <em>quoted strings</em>.
+	 *
+	 * <p>Defaults to a single quote ({@code '}).
+	 *
+	 * <p>You may change the quote character to anything that makes sense for
+	 * your use case; however, the primary use case is to allow you to use double
+	 * quotes in {@link #textBlock}.
+	 *
+	 * @since 5.8.2
+	 * @see #textBlock
+	 */
+	@API(status = EXPERIMENTAL, since = "5.8.2")
+	char quoteCharacter() default '\'';
+
 	/**
 	 * The column delimiter character to use when reading the {@linkplain #value lines}.
 	 *

junit-jupiter-params/src/test/java/org/junit/jupiter/params/ParameterizedTestIntegrationTests.java

@@ -91,10 +91,10 @@
 class ParameterizedTestIntegrationTests {
 
 	@ParameterizedTest
-	@CsvSource(textBlock = """
+	@CsvSource(quoteCharacter = '"', textBlock = """
 				apple,         1
 				banana,        2
-				'lemon, lime', 0xF1
+				"lemon, lime", 0xF1
 				strawberry,    700_000
 			""")
 	void executesLinesFromTextBlock(String fruit, int rank) {