Mutation with only a string return.

[DJWassink]

Heya, awesome work on this project!

I really love getting typescript defenitions for my queries but I am running into a issue with a single mutation which only returns a String!

My mutations schema look like this:

type Mutation {
    authenticate(email: String!, password: String!): String!
    register(email: String!, userName: String!, password: String!, password2: String!): User!
}

And in my react component:

//in register.tsx
const RegisterMutation = gql`
    mutation register($email: String!, $userName: String!, $password: String!, $password2: String!) {
        register(email: $email, userName: $userName, password: $password, password2: $password2) {
            id
        }
    }
`;

//in login.tsx
const AuthenticateMutation = gql`
    mutation authenticate($email: String!, $password: String!) {
        authenticate(email: $email, password: $password)
    }
`;

The RegisterMutation is returning a user object where I am selecting the id only and the defenitions gets generated correctly but for the AuthenticateMutation I am not selecting anything because it only returns a string.

running the command below will result in a crash

 gql-gen --file schema.json --template typescript --out ./typings/b.ts ./src/account/login.tsx

TypeError: Cannot read property 'fields' of undefined
    at /home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/handlers/inner-models-builer.js:67:29
    at Array.forEach (native)
    at Object.exports.buildInnerModelsArray (/home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/handlers/inner-models-builer.js:11:47)
    at Object.exports.handleOperation (/home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/handlers/operation-handler.js:51:49)
    at /home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/engine/codegen.js:20:56
    at Array.forEach (native)
    at Object.exports.prepareCodegen (/home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/engine/codegen.js:17:30)
    at Transform (/home/dirkjan/.config/yarn/global/node_modules/graphql-code-generator/dist/engine/transform-engine.js:27:29)
Error: TypeError: Cannot read property 'fields' of undefined

I guess it has something to do with the fact that it returns a string instead of a object?

[DJWassink]

For now I have solved the issue by returning a type only containing a single string, so in my schema I now have added:

type Token {
    token: String!
}

And changed the mutation object to:

type Mutation {
    authenticate(email: String!, password: String!): Token!
    register(email: String!, userName: String!, password: String!, password2: String!): User!
}

And in my react component my mutation looks like this:

const AuthenticateMutation = gql`
    mutation authenticate($email: String!, $password: String!) {
        authenticate(email: $email, password: $password) {
            token
        }
    }
`;

So I assume to let the codegenerator generate code an object as return type is required?

[dotansimha]

Fixed in 0.8.0 :)

@DJWassink