ScotchParserBaseTest.java

package scotch.compiler.parser;

import static java.util.Arrays.asList;

import java.util.List;
import java.util.Map;
import java.util.function.Function;
import org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import scotch.compiler.parser.ScotchParser.ModuleContext;

public abstract class ScotchParserBaseTest {

    protected ScotchParser getParser(String... input) {
        ScotchParser parser = new ScotchParser(new CommonTokenStream(new ScotchLayoutLexer(new ScotchLexer(new ANTLRInputStream(String.join("\n", input))))));
        parser.removeErrorListeners();
        parser.addErrorListener(new BaseErrorListener() {
            @Override
            public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) {
                if (!msg.startsWith("extraneous input ';'")) {
                    throw new ParseTestException(msg + " (line " + line + "@" + charPositionInLine + ")");
                }
            }
        });
        return parser;
    }

    protected String parse(Function<? super ScotchParser, ? extends ParserRuleContext> function, String... input) {
        ScotchParser parser = getParser(input);
        return function.apply(parser).toStringTree(parser);
    }

    protected Map<String, List<ModuleContext>> parseModules(String... input) {
        return new ModulesMapper().map(asList(getParser(input).modules()));
    }

    protected ParserRuleContext parseTree(Function<? super ScotchParser, ? extends ParserRuleContext> function, String... input) {
        return function.apply(getParser(input));
    }

    private static final class ParseTestException extends RuntimeException {

        public ParseTestException(String message) {
            super(message);
        }
    }
}