Unexpected <EOF> while using graphql

Question

Getting EOF error every time at same line, changed code many times and even degraded to previous versions of graphql but no positive results. My code is:

const graphql = require('graphql')
const _ = require('lodash')
 const {
     GraphQLObjectType,
     GraphQLString,
     GraphQLInt,
     GraphQLSchema
 } = graphql

const users = [
    {id: '1', firstName: 'Ansh', age: 20},
    {id: '2', firstName: 'Ram', age: 21},
    {id: '3', firstName: 'Sham', age: 20}
]

 const UserType = new GraphQLObjectType({
     name: 'User',
     fields: {
        id: {type: GraphQLString},
        firstName: {type: GraphQLString},
        age: {type: GraphQLInt}
     }
 })

 const RootQuery = new GraphQLObjectType({
     name: 'RootQueryType',
          fields: {
             user: {
                 type: UserType,
                 args: {id: {type: GraphQLString}},
                 resolve(parentValue, args) { 
                    return _.find(users, {id: args.id})
                 }
             }
         }
     })

 module.exports = new GraphQLSchema({
    query: RootQuery 
})

Error is:

    {
        "errors": [
        {
            "message": "Syntax Error GraphQL request (30:1) Unexpected <EOF>\n\n29: \n30: \n    ^\n",
            "locations": [
            {
                "line": 30,
                "column": 1
            }
            ]
        }
        ]
    }

Answer 1

The issue is because the query you're passing might be empty.

For example:

curl -X POST http://localhost:4000/graphql \ 
-H "Content-Type: application/json" \
-d '{"query": "{ user { id } }"}'

works fine.

But if you make something like:

curl -X POST http://localhost:4000/graphql \
-H "Content-Type: application/json" \
-d '{"query": ""}'

You'll get unexpected < EOF >

Also, check GraphQL end of line issue.

Answer 2

I had comments in the schema.graphql file:

"""
Some comments
"""

I removed the comments and the Unexpected <EOF> error went away.

Answer 3

It's because there's no actual query so you get unexpected EOF (End of File).

Guessing that you're using GraphiQL (because your EOF message says line 30); you need to add a query on the left-hand panel of GraphiQL in the browser. Something which conforms to your RootQuery like:

{
  user(id: "1") {
    id,
    firstName,
    age
  }
}