Cannot read property 'name' of null (react-admin) - react-admin

Question

I have the most simple code possible to check react-admin:
import React, { Component } from "react";
import buildGraphQLProvider from "ra-data-graphql-simple";
import { Admin, Resource } from "react-admin";
import posts from "./routes/posts";
class App extends Component {
constructor() {
super();
this.state = { dataProvider: null };
}
componentDidMount() {
buildGraphQLProvider({
clientOptions: { uri: "https://countries.trevorblades.com" }
})
.then(dataProvider => this.setState({ dataProvider }))
.catch(e => console.log(e.message));
}
render() {
const { dataProvider } = this.state;
if (!dataProvider) {
return <div>Loading</div>;
}
return (
<Admin dataProvider={dataProvider}>
<Resource name="posts" {...posts} />
</Admin>
);
//or, directly return <Admin dataProvider={dataProvider} />
}
}
export default App;
but I always get the same error in console: Cannot read property 'name' of null
My dependences are:
"graphql": "14.6.0",
"graphql-tag": "2.10.1",
"ra-core": "3.1.4",
"ra-data-graphql-simple": "3.1.4",
"react": "16.12.0",
"react-admin": "3.2.0",
"react-apollo": "3.1.3",
"react-dom": "16.12.0",
"react-scripts": "3.0.1"
What I'm doing wrong??

Answer 1

I had the same problem.
The issue was that I was missing Mutation type in my graphql schema, therefore the check
type.name !== schema.mutationType.name
threw an error, because schema.mutationType was undefined
Make sure you have a Mutation type in your schema even if it's an empty one

Answer 2

Maybe you wanted to write?
<Resource name="posts" />
Have you read the docs?
https://marmelab.com/react-admin/Resource.html