Type mismatch: cannot convert from Class<RulesGenerator> to Class<? extends IGenerator2> xtest error

Question

I am using this Xtest code to create a demo homeAutomation language github source but when the automatic code is generated i am getting errors in file AbstractHomeAutomationRuntimeModule like "type mismatch: cannot convert from Class to Class" i'm adding a pic for further referance

i got this error after adding the file AbstractHomeAutomationRuntimeModule RulesGenerator.xtend

   /*
 * generated by Xtext 2.10.0
 */
package org.xtext.example.home.generator

import org.eclipse.emf.ecore.resource.Resource
import org.eclipse.xtext.generator.AbstractGenerator
import org.eclipse.xtext.generator.IFileSystemAccess2
import org.eclipse.xtext.generator.IGeneratorContext
import org.xtext.example.home.homeAutomation.Device
import org.xtext.example.home.homeAutomation.Model
import java.util.Scanner
import org.eclipse.emf.ecore.resource.Resource
import org.eclipse.xtext.generator.IFileSystemAccess
import org.eclipse.xtext.generator.IGenerator
import org.eclipse.xtend.lib.macro.declaration.Declaration
import org.xtext.example.home.homeAutomation.Rule

https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#code-generation
 */
class RulesGenerator implements IGenerator {

    override void doGenerate(Resource resource, IFileSystemAccess fsa) {
        val simpleClassName = resource.getURI.trimFileExtension.lastSegment
        if (resource.contents?.head == null) {
            return;
        }
        val declarations = resource.contents.head.eContents.filter(Declaration)
        fsa.generateFile(simpleClassName + '.java', '''
            public class «simpleClassName» {
                public static void fire(String event) {
                    «FOR device : declarations.filter(Device)»
                        «FOR state : device.states»
                            if (event.equals("«state.name»")) {
                                System.out.println("«device.name» is now «state.name»!");
                            }
                        «ENDFOR»
                    «ENDFOR»
                    «FOR rule : declarations.filter(Rule)»
                        if (event.equals("«rule.when.name»")) {
                            fire("«rule.then.name»");
                        }
                    «ENDFOR»
                }

                public static void main(String... args) {
                    try («Scanner.name» scanner = new «Scanner.name»(System.in)) {
                        System.out.println("Welcome home!");
                        System.out.println("Available commands : ");
                        «FOR device : declarations.filter(Device)»
                            «FOR state : device.states»
                                System.out.println("  «device.name» «state.name»" );
                            «ENDFOR»
                        «ENDFOR»
                        System.out.println("Have fun!");
                        while(true) {
                            String command = scanner.next();
                            «FOR device : declarations.filter(Device)»
                                if (command.equalsIgnoreCase("«device.name»")) {
                                    String secondaryCommand = scanner.next();
                                    «FOR state : device.states»
                                        if (secondaryCommand.equalsIgnoreCase("«state.name»")) {
                                            fire("«state.name»");
                                        } else 
                                    «ENDFOR»
                                    {
                                        System.out.println("«device.name» can only have the following states: «device.states.map[name].
                            join(',')».");
                                    }
                                }
                            «ENDFOR»
                            if (command.equalsIgnoreCase("bye")) {
                                System.out.println("Ciao!");
                                break;
                            }
                        }
                    }
                }
            }
        ''')
    }

    def ruleMethodName(Rule device) {
        'execute' + device.description.replaceAll('\\W', '_')
    }
}

Error is in this auto generate file AbstractHomeAutomationRuntimeModule

/*
 * generated by Xtext 2.10.0
 */
package org.xtext.example.home;

import com.google.inject.Binder;
import com.google.inject.Provider;
import com.google.inject.name.Names;
import java.util.Properties;
import org.eclipse.xtext.Constants;
import org.eclipse.xtext.IGrammarAccess;
import org.eclipse.xtext.generator.IGenerator2;
import org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider;
import org.eclipse.xtext.naming.IQualifiedNameProvider;
import org.eclipse.xtext.parser.IParser;
import org.eclipse.xtext.parser.ITokenToStringConverter;
import org.eclipse.xtext.parser.antlr.AntlrTokenDefProvider;
import org.eclipse.xtext.parser.antlr.AntlrTokenToStringConverter;
import org.eclipse.xtext.parser.antlr.IAntlrTokenFileProvider;
import org.eclipse.xtext.parser.antlr.ITokenDefProvider;
import org.eclipse.xtext.parser.antlr.Lexer;
import org.eclipse.xtext.parser.antlr.LexerBindings;
import org.eclipse.xtext.parser.antlr.LexerProvider;
import org.eclipse.xtext.resource.IContainer;
import org.eclipse.xtext.resource.IResourceDescriptions;
import org.eclipse.xtext.resource.containers.IAllContainersState;
import org.eclipse.xtext.resource.containers.ResourceSetBasedAllContainersStateProvider;
import org.eclipse.xtext.resource.containers.StateBasedContainerManager;
import org.eclipse.xtext.resource.impl.ResourceDescriptionsProvider;
import org.eclipse.xtext.resource.impl.ResourceSetBasedResourceDescriptions;
import org.eclipse.xtext.scoping.IGlobalScopeProvider;
import org.eclipse.xtext.scoping.IScopeProvider;
import org.eclipse.xtext.scoping.IgnoreCaseLinking;
import org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider;
import org.eclipse.xtext.scoping.impl.DefaultGlobalScopeProvider;
import org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider;
import org.eclipse.xtext.serializer.ISerializer;
import org.eclipse.xtext.serializer.impl.Serializer;
import org.eclipse.xtext.serializer.sequencer.ISemanticSequencer;
import org.eclipse.xtext.serializer.sequencer.ISyntacticSequencer;
import org.eclipse.xtext.service.DefaultRuntimeModule;
import org.eclipse.xtext.service.SingletonBinding;
import org.xtext.example.home.generator.RulesGenerator;
import org.xtext.example.home.parser.antlr.HomeAutomationAntlrTokenFileProvider;
import org.xtext.example.home.parser.antlr.HomeAutomationParser;
import org.xtext.example.home.parser.antlr.internal.InternalHomeAutomationLexer;
import org.xtext.example.home.scoping.HomeAutomationScopeProvider;
import org.xtext.example.home.serializer.HomeAutomationSemanticSequencer;
import org.xtext.example.home.serializer.HomeAutomationSyntacticSequencer;
import org.xtext.example.home.services.HomeAutomationGrammarAccess;
import org.xtext.example.home.validation.HomeAutomationValidator;

/**
 * Manual modifications go to {@link HomeAutomationRuntimeModule}.
 */
@SuppressWarnings("all")
public abstract class AbstractHomeAutomationRuntimeModule extends DefaultRuntimeModule {

    protected Properties properties = null;

    @Override
    public void configure(Binder binder) {
        properties = tryBindProperties(binder, "org/xtext/example/home/HomeAutomation.properties");
        super.configure(binder);
    }

    public void configureLanguageName(Binder binder) {
        binder.bind(String.class).annotatedWith(Names.named(Constants.LANGUAGE_NAME)).toInstance("org.xtext.example.home.HomeAutomation");
    }

    public void configureFileExtensions(Binder binder) {
        if (properties == null || properties.getProperty(Constants.FILE_EXTENSIONS) == null)
            binder.bind(String.class).annotatedWith(Names.named(Constants.FILE_EXTENSIONS)).toInstance("home");
    }

    // contributed by org.eclipse.xtext.xtext.generator.grammarAccess.GrammarAccessFragment2
    public ClassLoader bindClassLoaderToInstance() {
        return getClass().getClassLoader();
    }

    // contributed by org.eclipse.xtext.xtext.generator.grammarAccess.GrammarAccessFragment2
    public Class<? extends IGrammarAccess> bindIGrammarAccess() {
        return HomeAutomationGrammarAccess.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.serializer.SerializerFragment2
    public Class<? extends ISemanticSequencer> bindISemanticSequencer() {
        return HomeAutomationSemanticSequencer.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.serializer.SerializerFragment2
    public Class<? extends ISyntacticSequencer> bindISyntacticSequencer() {
        return HomeAutomationSyntacticSequencer.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.serializer.SerializerFragment2
    public Class<? extends ISerializer> bindISerializer() {
        return Serializer.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Class<? extends IParser> bindIParser() {
        return HomeAutomationParser.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Class<? extends ITokenToStringConverter> bindITokenToStringConverter() {
        return AntlrTokenToStringConverter.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Class<? extends IAntlrTokenFileProvider> bindIAntlrTokenFileProvider() {
        return HomeAutomationAntlrTokenFileProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Class<? extends Lexer> bindLexer() {
        return InternalHomeAutomationLexer.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Class<? extends ITokenDefProvider> bindITokenDefProvider() {
        return AntlrTokenDefProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public Provider<InternalHomeAutomationLexer> provideInternalHomeAutomationLexer() {
        return LexerProvider.create(InternalHomeAutomationLexer.class);
    }

    // contributed by org.eclipse.xtext.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment2
    public void configureRuntimeLexer(Binder binder) {
        binder.bind(Lexer.class)
            .annotatedWith(Names.named(LexerBindings.RUNTIME))
            .to(InternalHomeAutomationLexer.class);
    }

    // contributed by org.eclipse.xtext.xtext.generator.validation.ValidatorFragment2
    @SingletonBinding(eager=true)
    public Class<? extends HomeAutomationValidator> bindHomeAutomationValidator() {
        return HomeAutomationValidator.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.scoping.ImportNamespacesScopingFragment2
    public Class<? extends IScopeProvider> bindIScopeProvider() {
        return HomeAutomationScopeProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.scoping.ImportNamespacesScopingFragment2
    public void configureIScopeProviderDelegate(Binder binder) {
        binder.bind(IScopeProvider.class).annotatedWith(Names.named(AbstractDeclarativeScopeProvider.NAMED_DELEGATE)).to(ImportedNamespaceAwareLocalScopeProvider.class);
    }

    // contributed by org.eclipse.xtext.xtext.generator.scoping.ImportNamespacesScopingFragment2
    public Class<? extends IGlobalScopeProvider> bindIGlobalScopeProvider() {
        return DefaultGlobalScopeProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.scoping.ImportNamespacesScopingFragment2
    public void configureIgnoreCaseLinking(Binder binder) {
        binder.bindConstant().annotatedWith(IgnoreCaseLinking.class).to(false);
    }

    // contributed by org.eclipse.xtext.xtext.generator.exporting.QualifiedNamesFragment2
    public Class<? extends IQualifiedNameProvider> bindIQualifiedNameProvider() {
        return DefaultDeclarativeQualifiedNameProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.builder.BuilderIntegrationFragment2
    public Class<? extends IContainer.Manager> bindIContainer$Manager() {
        return StateBasedContainerManager.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.builder.BuilderIntegrationFragment2
    public Class<? extends IAllContainersState.Provider> bindIAllContainersState$Provider() {
        return ResourceSetBasedAllContainersStateProvider.class;
    }

    // contributed by org.eclipse.xtext.xtext.generator.builder.BuilderIntegrationFragment2
    public void configureIResourceDescriptions(Binder binder) {
        binder.bind(IResourceDescriptions.class).to(ResourceSetBasedResourceDescriptions.class);
    }

    // contributed by org.eclipse.xtext.xtext.generator.builder.BuilderIntegrationFragment2
    public void configureIResourceDescriptionsPersisted(Binder binder) {
        binder.bind(IResourceDescriptions.class).annotatedWith(Names.named(ResourceDescriptionsProvider.PERSISTED_DESCRIPTIONS)).to(ResourceSetBasedResourceDescriptions.class);
    }

    // contributed by org.eclipse.xtext.xtext.generator.generator.GeneratorFragment2
    public Class<? extends IGenerator2> bindIGenerator2() {
        return RulesGenerator.class;
    }

}

Answer 1

The error says that RulesGenerator should implement IGenerator2 interface (not IGenerator).

Answer 2

I had a similar issue, but my DslGenerator was extending from AbstractGenerator which has an implementation of IGenerator2. Everything look good but it still complained of a type mismatch between my generator and IGenerator2 in AbstractDslRuntimeModule.

I had VS Code with the source code open in the background. Apparently something was blocking or interfering when generating the xtext artifacts. Closing VS code, clean and generate the xtext artifact and it build correctly.