Here is my simple graphql express app
const express = require('express');
const graphqlHTTP = require('express-graphql');
const app = express();
app.use(
'/graphql',
graphqlHTTP({
graphiql: true,
})
);
app.listen(4000, () => {
console.log("listening for request!");
});
I'm getting the following errors when I run it:
graphqlHTTP({
^
TypeError: graphqlHTTP is not a function
at Object.<anonymous> (D:\PersonalProjects\GraphQL\server\app.js:7:5)
at Module._compile (internal/modules/cjs/loader.js:1138:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
at Module.load (internal/modules/cjs/loader.js:986:32)
at Function.Module._load (internal/modules/cjs/loader.js:879:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
at internal/main/run_main_module.js:17:47
How can I fix it? Thanks in advance!
Look at the documentation:
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.
Quentin's answer was on spot. Apparently the npm documentation was updated but some of the tutorials on YouTube were not. That's why there's a certain degree of confusion for learners like myself. There are still outdated versions of the code like
This one: https://github.com/iamshaunjp/graphql-playlist/blob/lesson-36/server/app.js
This one: https://github.com/WebDevSimplified/Learn-GraphQL/blob/master/server.js
Or this one: https://github.com/bradtraversy/customerbase/blob/master/server.js
They should all be updated to
const { graphqlHTTP } = require('express-graphql');
and then
app.use('/graphql', graphqlHTTP({
schema:schema,
graphiql:true
}));
Just to make it more clear:
Before "express-graphql" was returning a direct function or a class with the function and we could assign it to any variable like graphqlServer
const graphqlServer = require('express-graphql');
Now, it returns the whole object that has a function inside it named "graphqlHTTP". hence the code should be exactly
const { graphqlHTTP } = require('express-graphql');
and to make a connection,
app.use('/graphql', graphqlHTTP({
// your config
}));