What causes "Failed to parse CSV input configured via ${annotation}" in junit-team/junit5?

Make every record have the same number of columns as the parameter list.

junit-team/junit5 · error · CsvParsingException

Failed to parse CSV input configured via ${annotation}

Error message

Failed to parse CSV input configured via ${annotation}

What it means

CsvArgumentsProvider.handleCsvException wraps any non-PreconditionViolation throwable raised by the fastcsv reader into a CsvParsingException with this message (it prints the source annotation). It indicates the CSV content declared via @CsvSource could not be parsed under the configured delimiter, quote, and record-separator rules.

Source

Thrown at junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/CsvArgumentsProvider.java:144

		return ((NamedCsvRecord) record).getHeader();
	}

	@SuppressWarnings({ "ReferenceEquality", "StringEquality" })
	private static @Nullable String resolveNullMarker(String record) {
		return record == CsvReaderFactory.DefaultFieldModifier.NULL_MARKER ? null : record;
	}

	/**
	 * @return this method always throws an exception and therefore never
	 * returns anything; the return type is merely present to allow this
	 * method to be supplied as the operand in a {@code throw} statement
	 */
	static RuntimeException handleCsvException(Throwable throwable, Annotation annotation) {
		UnrecoverableExceptions.rethrowIfUnrecoverable(throwable);
		if (throwable instanceof PreconditionViolationException exception) {
			throw exception;
		}
		throw new CsvParsingException("Failed to parse CSV input configured via " + annotation, throwable);
	}

}

View on GitHub (pinned to 956246301e)

Solutions

Make every record have the same number of columns as the parameter list.
Wrap any field that contains the delimiter in the configured quote character.
Set delimiter / quoteChar / emptyValue / nullValue explicitly on @CsvSource to match the data.
Normalize quotes and strip BOM / non-breaking spaces from the source.
Switch to the textBlock form for multi-line CSV to make structure visible.

Example fix

// before
@ParameterizedTest
@CsvSource({
    "name,age",
    "Alice,30,extra"   // column count differs from header
})
void test(String name, int age) { }

// after
@ParameterizedTest
@CsvSource({
    "name,age",
    "Alice,30"
})
void test(String name, int age) { }

Defensive patterns

Strategy: validation

Validate before calling

// Validate every @CsvSource row before declaring the test.
String[][] rows = { {"name","age"}, {"Alice,30"} };
int cols = rows[0].length;
for (String[] r : rows) {
    // simple sanity: same field count when split on the delimiter
    long count = r[0].chars().filter(c -> c == ',').count() + 1;
    if (count != cols) throw new IllegalArgumentException("inconsistent CSV row: " + r[0]);
}

Try / catch

try {
    // execute parameterized test
} catch (CsvParsingException e) {
    // log the annotation + cause, then correct the @CsvSource value/textBlock
}

Prevention

Run the CSV through a real CSV parser (e.g. fastcsv) in a scratch test before declaring @CsvSource.
Quote every field that may contain the delimiter.
Prefer the textBlock form so column alignment is visually obvious.
Normalize quotes and strip BOM / non-breaking spaces from pasted CSV.

When it happens

Trigger: Malformed @CsvSource value or textBlock: a quoted field missing its closing quote, a record whose column count diverges from the others, a stray delimiter, or an incompatible CsvReaderConfiguration.

Common situations: Pasting tab-separated data into a comma-separated @CsvSource; smart quotes / non-breaking spaces copied from a doc; inconsistent column counts across rows; wrong delimiter or quoteChar attribute.

Related errors

AI-assisted analysis of junit-team/junit5@956246301e (2026-08-04). Data as JSON: /data/errors/d0e11e7fcd612b30.json. Report an issue: GitHub.