Type-graphql: Creating an app without any queries throws an error

[borremosch]

Describe the bug
When I create an app that has no queries, but only mutations, an error is thrown.

To Reproduce
Create a project with this simple reducer:

@Resolver()
class MyResolver{
  @Mutation(returns => Boolean)
  myMutation(){
    return true;
  }

Then try to build the schema:

const schema: GraphQLSchema = await buildSchema({
  resolvers: [MyResolver]
});

Expected behavior
I would expect this to work, as I don't see a reason why having at least one query should be mandatory.

Logs
Stack trace:

{ Error: Generating schema error
    at Function.<anonymous> (/my/project/node_modules/type-graphql/dist/schema/schema-generator.js:19:23)
    at Generator.next (<anonymous>)
    at fulfilled (/my/project/node_modules/tslib/tslib.js:104:62)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:757:11)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
  details:
   [ { Type Query must define one or more fields.
         at SchemaValidationContext.reportError (/my/project/node_modules/graphql/type/validate.js:99:19)
         at validateFields (/my/project/node_modules/graphql/type/validate.js:318:13)
         at validateTypes (/my/project/node_modules/graphql/type/validate.js:281:9)
         at validateSchema (/my/project/node_modules/graphql/type/validate.js:63:3)
         at graphqlImpl (/my/project/node_modules/graphql/graphql.js:57:61)
         at /my/project/node_modules/graphql/graphql.js:32:250
         at new Promise (<anonymous>)
         at Object.graphql (/my/project/node_modules/graphql/graphql.js:30:10)
         at Function.<anonymous> (/my/project/node_modules/type-graphql/dist/schema/schema-generator.js:17:48)
         at Generator.next (<anonymous>) message: 'Type Query must define one or more fields.' } ] }

Environment

• OS: Ubuntu 18.04.2 LTS
• Node version 10.15.3
• type-graphql version 0.17.1
• TypeScript version 3.3.1

[MichalLytek]

Type Query must define one or more fields means that one of your method must be decorated with @Query().

It's invalid to create a schema without a query type or a type without any fields. It's forced by GraphQL spec:

The query root operation type must be provided and must be an Object type.

https://graphql.github.io/graphql-spec/June2018/#sec-Schema

[dan-klasson]

@MichalLytek I have a use case where I have one resolver with only one mutation. And while doing testing it fails as I'm only loading this resolver. Using Nestjs btw.

[udayrajMT]

@MichalLytek I have a resolver that extends an @InterfaceType which has all the (common) @Query decorators. But I'm still getting the above error.

The interface:

@InterfaceType()
export abstract class IScopedResolver {
  @Query(returns => Contact, { nullable: true })
  async contact(...)
    //...

The resolver:

@Resolver(of => Contact)
export class ContactResolver extends IScopedResolver {
   // currently empty
}

I was referring to resolver-inheritance docs for this. What am I doing wrong here?

Let me know if I need to open a new issue.

[MichalLytek]

@udayrajMT @InterfaceType() is not equal to @Resolver(). Please read the manual again from top to bottom before trying to make some weird patterns.

[udayrajMT]

@MichalLytek right, I don't know what I was thinking - mixed up two examples I guess.
I hadn't created an interface since there were no @Fields to add to it.
Now I've created an empty one.

@InterfaceType()
export default abstract class IScoped { 
}

And changed the resolver interface as below-

@Resolver(of => IScoped, { isAbstract: true })
export abstract class IScopedResolver {
// ... queries
}

Yet to test this completely, but thanks anyway for the quick reply and clarification!