Documentation mentions `ListWriter`

[sdavids]

https://docs.junit.org/6.0.3/writing-tests/built-in-extensions.html#TempDirectory

@Test
void writeItemsToFile(@TempDir Path tempDir) throws IOException {
	Path file = tempDir.resolve("test.txt");

	new ListWriter(file).write("a", "b", "c");

	assertEquals(List.of("a,b,c"), Files.readAllLines(file));
}

This code snippet and others use ListWriter.

ListWriter is not a part of the JUnit API nor the JDK.

Please rewrite the example to only use JDK or JUnit API, thanks.

This should be improved in the 5.x and 6.x docs.

[sdavids]

For JUnit 5 maybe with:

https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#write-java.nio.file.Path-java.lang.Iterable-java.nio.charset.Charset-java.nio.file.OpenOption...-

For JUnit 6 maybe with:

https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/nio/file/Files.html#writeString(java.nio.file.Path,java.lang.CharSequence,java.nio.charset.Charset,java.nio.file.OpenOption...)

[mpkorstanje]

Please rewrite the example to only use JDK or JUnit API, thanks.

What concrete problem would this solve for you?

[jbduncan]

I can't speak for the OP, but if it were me, it would make it easier to try out JUnit by copying the example without being confused by non-existent APIs or compiler messages.

[mpkorstanje]

I assume there was some intention to show a non-trivial usage. So it might be a possibility to include the code of the list writer instead of rewriting the example.

junit-framework/documentation/src/main/java/example/util/ListWriter.java

Line 18 in 31409ef

public class ListWriter {

[sbrannen]

This code snippet and others use ListWriter.

The same is true for a number of examples in the User Guide.

For example, the AutoCloseDemo at the end of that section uses a demo WebClient for which there is also no source code shown.

However, the source code for most (if not all) of the examples is available in the documentation project. See WebClient.

Thus, perhaps it's sufficient to link to the demo source code in such scenarios and point out that it's only for demonstration purposes.