Allow potentially unlimited maxCharsPerColumn in Csv{File}Source

documentation/src/docs/asciidoc/release-notes/release-notes-5.11.0.adoc

@@ -186,6 +186,8 @@ on GitHub.
 * `@TempDir` now fails fast in case the annotated target is of type `File` and
   `TempDirFactory::createTempDirectory` returns a `Path` that does not belong to the
   default file system.
+* Allow potentially unlimited characters per column in `@CsvSource` and `@CsvFileSource`
+  by specifying `maxCharsPerColumn = -1`.
 
 
 [[release-notes-5.11.0-junit-vintage]]

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

@@ -206,7 +206,8 @@
 	/**
 	 * The maximum number of characters allowed per CSV column.
 	 *
-	 * <p>Must be a positive number.
+	 * <p>Must be a positive number or {@code -1} to allow an unlimited number
+	 * of characters.
 	 *
 	 * <p>Defaults to {@code 4096}.
 	 *

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

@@ -77,8 +77,8 @@ private static CsvParserSettings createParserSettings(String delimiter, String l
 		settings.setAutoConfigurationEnabled(false);
 		settings.setIgnoreLeadingWhitespaces(ignoreLeadingAndTrailingWhitespace);
 		settings.setIgnoreTrailingWhitespaces(ignoreLeadingAndTrailingWhitespace);
-		Preconditions.condition(maxCharsPerColumn > 0,
-			() -> "maxCharsPerColumn must be a positive number: " + maxCharsPerColumn);
+		Preconditions.condition(maxCharsPerColumn > 0 || maxCharsPerColumn == -1,
+			() -> "maxCharsPerColumn must be a positive number or -1: " + maxCharsPerColumn);
 		settings.setMaxCharsPerColumn(maxCharsPerColumn);
 		// Do not use the built-in support for skipping rows/lines since it will
 		// throw an IllegalArgumentException if the file does not contain at least

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

@@ -261,7 +261,8 @@
 	/**
 	 * The maximum number of characters allowed per CSV column.
 	 *
-	 * <p>Must be a positive number.
+	 * <p>Must be a positive number or {@code -1} to allow an unlimited number
+	 * of characters.
 	 *
 	 * <p>Defaults to {@code 4096}.
 	 *

jupiter-tests/src/test/java/org/junit/jupiter/params/provider/CsvArgumentsProviderTests.java

@@ -18,6 +18,7 @@
 import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.platform.commons.JUnitException;
 import org.junit.platform.commons.PreconditionViolationException;
 
@@ -296,20 +297,21 @@ void throwsExceptionWhenSourceExceedsDefaultMaxCharsPerColumnConfig() {
 
 	@Test
 	void providesArgumentsForExceedsSourceWithCustomMaxCharsPerColumnConfig() {
-		var annotation = csvSource().lines("0".repeat(4097)).delimiter(';').maxCharsPerColumn(4097).build();
+		var annotation = csvSource().lines("0".repeat(4097)).maxCharsPerColumn(4097).build();
 
 		var arguments = provideArguments(annotation);
 
 		assertThat(arguments.toArray()).hasSize(1);
 	}
 
-	@Test
-	void throwsExceptionWhenMaxCharsPerColumnIsNotPositiveNumber() {
-		var annotation = csvSource().lines("41").delimiter(';').maxCharsPerColumn(-1).build();
+	@ParameterizedTest
+	@ValueSource(ints = { Integer.MIN_VALUE, -2, 0 })
+	void throwsExceptionWhenMaxCharsPerColumnIsNotPositiveNumberOrMinusOne(int maxCharsPerColumn) {
+		var annotation = csvSource().lines("41").maxCharsPerColumn(maxCharsPerColumn).build();
 
 		assertThatExceptionOfType(PreconditionViolationException.class)//
 				.isThrownBy(() -> provideArguments(annotation).findAny())//
-				.withMessageStartingWith("maxCharsPerColumn must be a positive number: -1");
+				.withMessageStartingWith("maxCharsPerColumn must be a positive number or -1: " + maxCharsPerColumn);
 	}
 
 	@Test

jupiter-tests/src/test/java/org/junit/jupiter/params/provider/CsvFileArgumentsProviderTests.java

@@ -19,7 +19,6 @@
 import static org.mockito.Mockito.when;
 
 import java.io.ByteArrayInputStream;
-import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -30,6 +29,7 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvFileArgumentsProvider.InputStreamProvider;
 import org.junit.platform.commons.JUnitException;
 import org.junit.platform.commons.PreconditionViolationException;
@@ -410,7 +410,7 @@ void readsLineFromDefaultMaxCharsFileWithDefaultConfig(@TempDir Path tempDir) th
 	}
 
 	@Test
-	void readsLineFromExceedsMaxCharsFileWithCustomConfig(@TempDir Path tempDir) throws java.io.IOException {
+	void readsLineFromExceedsMaxCharsFileWithCustomExplicitConfig(@TempDir Path tempDir) throws Exception {
 		var csvFile = writeClasspathResourceToFile("exceeds-default-max-chars.csv",
 			tempDir.resolve("exceeds-default-max-chars.csv"));
 		var annotation = csvFileSource()//
@@ -426,24 +426,49 @@ void readsLineFromExceedsMaxCharsFileWithCustomConfig(@TempDir Path tempDir) thr
 	}
 
 	@Test
-	void throwsExceptionWhenMaxCharsPerColumnIsNotPositiveNumber(@TempDir Path tempDir) throws java.io.IOException {
+	void readsLineFromExceedsMaxCharsFileWithCustomUnlimitedConfig(@TempDir Path tempDir) throws Exception {
+		var csvFile = tempDir.resolve("test.csv");
+		try (var out = Files.newBufferedWriter(csvFile)) {
+			var chunks = 10;
+			var chunk = "a".repeat(8192);
+			for (long i = 0; i < chunks; i++) {
+				out.write(chunk);
+			}
+		}
+
+		var annotation = csvFileSource()//
+				.encoding("ISO-8859-1")//
+				.maxCharsPerColumn(-1)//
+				.files(csvFile.toAbsolutePath().toString())//
+				.build();
+
+		var arguments = provideArguments(new CsvFileArgumentsProvider(), annotation);
+
+		assertThat(arguments).hasSize(1);
+	}
+
+	@ParameterizedTest
+	@ValueSource(ints = { Integer.MIN_VALUE, -2, 0 })
+	void throwsExceptionWhenMaxCharsPerColumnIsNotPositiveNumberOrMinusOne(int maxCharsPerColumn, @TempDir Path tempDir)
+			throws Exception {
 		var csvFile = writeClasspathResourceToFile("exceeds-default-max-chars.csv",
 			tempDir.resolve("exceeds-default-max-chars.csv"));
 		var annotation = csvFileSource()//
 				.encoding("ISO-8859-1")//
 				.resources("exceeds-default-max-chars.csv")//
-				.maxCharsPerColumn(-1).files(csvFile.toAbsolutePath().toString())//
+				.maxCharsPerColumn(maxCharsPerColumn)//
+				.files(csvFile.toAbsolutePath().toString())//
 				.build();
 
 		var exception = assertThrows(PreconditionViolationException.class, //
 			() -> provideArguments(new CsvFileArgumentsProvider(), annotation).findAny());
 
 		assertThat(exception)//
-				.hasMessageStartingWith("maxCharsPerColumn must be a positive number: -1");
+				.hasMessageStartingWith("maxCharsPerColumn must be a positive number or -1: " + maxCharsPerColumn);
 	}
 
 	@Test
-	void throwsExceptionForExceedsMaxCharsFileWithDefaultConfig(@TempDir Path tempDir) throws java.io.IOException {
+	void throwsExceptionForExceedsMaxCharsFileWithDefaultConfig(@TempDir Path tempDir) throws Exception {
 		var csvFile = writeClasspathResourceToFile("exceeds-default-max-chars.csv",
 			tempDir.resolve("exceeds-default-max-chars.csv"));
 		var annotation = csvFileSource()//
@@ -461,7 +486,7 @@ void throwsExceptionForExceedsMaxCharsFileWithDefaultConfig(@TempDir Path tempDi
 	}
 
 	@Test
-	void ignoresLeadingAndTrailingSpaces(@TempDir Path tempDir) throws IOException {
+	void ignoresLeadingAndTrailingSpaces(@TempDir Path tempDir) throws Exception {
 		var csvFile = writeClasspathResourceToFile("leading-trailing-spaces.csv",
 			tempDir.resolve("leading-trailing-spaces.csv"));
 		var annotation = csvFileSource()//
@@ -477,7 +502,7 @@ void ignoresLeadingAndTrailingSpaces(@TempDir Path tempDir) throws IOException {
 	}
 
 	@Test
-	void trimsLeadingAndTrailingSpaces(@TempDir Path tempDir) throws IOException {
+	void trimsLeadingAndTrailingSpaces(@TempDir Path tempDir) throws Exception {
 		var csvFile = writeClasspathResourceToFile("leading-trailing-spaces.csv",
 			tempDir.resolve("leading-trailing-spaces.csv"));
 		var annotation = csvFileSource()//
@@ -527,7 +552,7 @@ private static <T> T[] array(T... elements) {
 		return elements;
 	}
 
-	private static Path writeClasspathResourceToFile(String name, Path target) throws IOException {
+	private static Path writeClasspathResourceToFile(String name, Path target) throws Exception {
 		try (var in = CsvFileArgumentsProviderTests.class.getResourceAsStream(name)) {
 			Files.copy(in, target);
 		}