Question

I have a parser rule in ANTLR that takes a parameter.

tincture [Tinctures tinctures] returns [Tincture tincture]   
    :   { String tinctureName = ""; }
    (   COLOUR { tinctureName = $COLOUR.text; }
    |   METAL  { tinctureName = $METAL.text; }
    |   FUR    { tinctureName = $FUR.text; }
    )
    {
        try {
            $tincture = tinctures.getTincture(tinctureName);
        } catch (UnknownTinctureException e) {
            throw new MyRecognitionException("Unknown tincture found.", e);
        }
    }
    ;

How can I write a test for this in GUnit?

I have successfully written tests for my Lexer rules as they do not have any parameters.
If I write the following I get “java.lang.NoSuchMethodException: mypackage.BlazonParser.tincture()”

tincture
    :   "gules"             OK
        "sable"             OK
        "blah"              FAIL

I can find very little documentation around GUnit apart from this page, but it hasn’t covered this.

Answer 1

Looking at the official docs, it seems you can’t provide a parameter to the rules you test, causing for the exception:

java.lang.NoSuchMethodException: mypackage.BlazonParser.tincture()

since tincture expects a Tinctures as parameter.

You could keep keep using gUnit, and use JUnit for those rules containing parameters. But mixing gUnit and JUnit is a bit messy, IMO, so personally, I simply use JUnit for all my ANTLR tests.

You could also have a look at aunit, a 3rd party ANTLR unit test suite. I haven’t looked at it in detail, and it seems to be lacking in documentation, but still, it could be what you’re looking for.