47

I am learning GraphQL for my project using this tutorial: https://www.youtube.com/watch?v=ZQL7tL2S0oQ&ab_channel=WebDevSimplified

and I get the error:

TypeError: expressGraphQL is not a function
at Object.<anonymous>

I have already tried:

  • this solution: graphqlHTTP is not a function - the program crashes all the same with {} parentheses and without them
  • adding a semicolon after various lines

The code for now looks like this:

const express = require ('express')
const { expressGraphQL } = require('express-graphql')
const app = express();

app.use('/graphql', expressGraphQL({
    graphiql: true,
})
)
app.listen(5000., () => console.log('Server Running'))

If I comment out this section:

app.use('/graphql', expressGraphQL({
graphiql: true,
})
)

the code works perfectly fine both with {} parentheses and without them.

Swantewit
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4 Answers4

127

Please replace your expressGraphQL with graphqlHTTP as it was destructured

Use:

const { graphqlHTTP } = require('express-graphql');

or

const expressGraphQL = require('express-graphql').graphqlHTTP

This is because a method called graphqlHTTP exist in the express-graphql module and you are destructure with another method name that does not exist in the module

I also noticed that you have a dot after 5000 on the app.listen function.

fatiu
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18

Use following as a solution.

const express = require('express');
const expressGraphQL = require('express-graphql').graphqlHTTP;


const app = express();

app.use('/graphql', expressGraphQL({
    graphiql:true
}));

app.listen(4000, () => {
    console.log('Listning');
}) 
5

Destructure graphqlHTTP from express-graphql

const { graphqlHTTP } = require("express-graphql");

app.use("/graphql", graphqlHTTP({ graphiql: true }));
Anbarasu_P
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3
const { graphqlHTTP } = require('express-graphql');

Note that it uses destructuring equivalent to:

const graphqlHTTP = require('express-graphql').graphqlHTTP;

require('express-graphql') returns an object with a property called graphqlHTTP that is the function you want to call.

You're trying to call the object itself as if it was a function.enter code here

  • 1
    Can anyone explain why this destructuring is needed? I worked with graph before and you didnt have to call .graphqlHTTP. I worked the same way this persons tutorial is stating so I am just curious what changed in the last year or so and why this is now needed? – MambaForever Nov 16 '22 at 16:10