Login Mutation for Graphql not finding user

Question

I am trying to create an authentication service with graphql and mongodb. I have created my login mutation which takes in the email and password. I am using bcrypt to hash and unhash the passwords.

It's not a import issue or a mongodb issue it's graphql.

const UserType = new GraphQLObjectType({
    name: 'User',
    fields: () => ({
        id: {type: GraphQLID},
        username: {type: GraphQLString},
        email: {type: GraphQLString},
        password: {type: GraphQLString},
        institution: {
            type: InstitutionType,
            resolve(parent, args){
                return Institution.findById(parent.institutionId)
            }
        }
    })
});

login:{
                type:GraphQLString,
                args:{
                    email: {type: GraphQLString},
                    password: {type: GraphQLString}
                },
                resolve: async (parent, { email, password }, { models, SECRET }) => {
                    const user = await models.User.findOne({ where: { email } });
                    if (!user) {
                      throw new Error('No user with that email');
                    }

                    const valid = await bcrypt.compare(password, user.password);
                    if (!valid) {
                      throw new Error('Incorrect password');
                    }

                    const token = jwt.sign(
                      {
                        user: _.pick(user, ['id', 'username']),
                      },
                      SECRET,
                      {
                        expiresIn: '1y',
                      },
                    );

                    return token;
                  },
                },
              }});

It should return a jwt token which can later be used for authentication. First I was running this in the graphiql in my browser:

mutation{
  login(email: "[email protected]", password:"password"){
  }
}

and it was giving me this in the console : "Syntax Error: Expected Name, found

Then I tried:

mutation{
  login(email: "[email protected]", password:"password"){
    username
  }
}

which gave me: Field \"login\" must not have a selection since type \"String\" has no subfields.

Daniel Rearden Daniel Rearden · Accepted Answer · 2019-02-17T19:10:26

The type for the login field on your Mutation type is GraphQLString, which is a scalar. Since scalars are leaf nodes, they do not have a selection set (i.e. other "child" fields). From the spec:

If selectionType is a scalar or enum:

The subselection set of that selection must be empty

If selectionType is an interface, union, or object

The subselection set of that selection must NOT BE empty

Curly brackets are used to indicate a selection set, so they should not be used when the return type for a field is a scalar or an enum. Your query needs to simple be:

mutation {
  login(email: "[email protected]", password:"password")
}

Login Mutation for Graphql not finding user

1 Answers