This gist demonstrates an bug in graphql-java-tools where checked-exception messages don't propogate

GraphQL-Java-Tools-CheckedException-Bug.java

import graphql.ExecutionResult;
import graphql.GraphQL;
import graphql.kickstart.tools.GraphQLQueryResolver;
import graphql.kickstart.tools.SchemaParser;
import graphql.schema.DataFetcher;
import graphql.schema.DataFetchingEnvironment;
import graphql.schema.GraphQLSchema;
import graphql.schema.idl.RuntimeWiring;
import graphql.schema.idl.SchemaGenerator;
import graphql.schema.idl.TypeDefinitionRegistry;

public class CheckedErrorTest {

    private static final String SCHEMA = "type Query { hello: String! }";

    public static void main(String[] args) {
        executeWithGraphQLJava();      // prints: Exception while fetching data (/hello) : *** MESSAGE ***
        executeWithGraphQLJavaTools(); // prints: Exception while fetching data (/hello) : null
    }

    public static void executeWithGraphQLJava() {
        final TypeDefinitionRegistry typedef = new graphql.schema.idl.SchemaParser().parse(SCHEMA);
        final RuntimeWiring wiring = RuntimeWiring.newRuntimeWiring().type("Query", builder -> builder.dataFetcher("hello", new ErrorFetcher())).build();
        final GraphQLSchema schema = new SchemaGenerator().makeExecutableSchema(typedef, wiring);
        final GraphQL graphql = GraphQL.newGraphQL(schema).build();
        final ExecutionResult result = graphql.execute("{ hello }");

        System.out.println(result.getErrors().iterator().next().getMessage());
    }

    public static void executeWithGraphQLJavaTools() {
        final GraphQLSchema schema = SchemaParser.newParser().schemaString(SCHEMA).resolvers(new ErrorResolver()).build().makeExecutableSchema();
        final GraphQL graphql = GraphQL.newGraphQL(schema).build();
        final ExecutionResult result = graphql.execute("{ hello }");

        System.out.println(result.getErrors().iterator().next().getMessage());
    }

    public static class ErrorResolver implements GraphQLQueryResolver {
        public String hello() throws Throwable {
            throw new Exception("*** MESSAGE ***");        }
    }

    private static class ErrorFetcher implements DataFetcher<String> {
        @Override
        public String get(final DataFetchingEnvironment env) throws Exception {
            throw new Exception("*** MESSAGE ***");
        }
    }

}