How To Throw Errors In Apollo Server v4?

Question

thanks for looking into this. So I am trying to migrate my Apollo Server from V3 to V4, I have a resolver that type checks for an Access Token and returns it like so

export class LoginResolver {
    @Mutation(() => AccessToken)
    async login(
        @Arg("email") email: string,
        @Arg("password") password: string,
        @Ctx() { prisma, res }: ProjectContext
    ): Promise<AccessToken> {
        // check if user exists
        const user = await prisma.user.findFirst({
            where: {
                email,
            },
        });
        if (!user) {
            throw new GraphQLError("No user found");
        }
        const valid = await verify(user.password, password);
        if (!valid) {
            throw new GraphQLError("Invalid Password");
        }
        // the user logged in successully
        res.cookie("*****", createRefreshToken(user), { httpOnly: true });
        const accessToken = createAccessToken(user);
        return {
            accessToken,
        };
    }
}

It returns the following error if the validation fails.

{
  "data": {},
  "error": {
    "message": "JSON.parse: unexpected character at line 1 column 1 of the JSON data"
  }
}

But however, if the right credentials were provided the API works just fine returning me a access token

{
  "data": {
    "login": {
      "accessToken": "..."
    }
  }
}

Correct Input:
email : [email protected]
password : password

Initially in Apollo V3 I had standard throw statements that worked just fine

        const user = await prisma.user.findFirst({
            where: {
                email,
            },
        });
        if (!user) {
            throw new Error("No user found");
        }
        const valid = await verify(user.password, password);
        if (!valid) {
            throw new Error("Invalid Password");
        }

digging into Apollo server’s docs I found that in V4 Apollo Error was removed and GraphQLError from graphql took it’s place, I gave that a shot but that does not seem to fix it.

Error Message from the console :

Unexpected error processing request: TypeError: graphqlError.toJSON is not a function
TypeError: graphqlError.toJSON is not a function
    at enrichError (D:ProjectsPlacementHubbackendnode_modules@apolloserversrcerrorNormalize.ts:84:30)
    at D:ProjectsPlacementHubbackendnode_modules@apolloserversrcerrorNormalize.ts:46:18
    at Array.map (<anonymous>)
    at normalizeAndFormatErrors (D:ProjectsPlacementHubbackendnode_modules@apolloserversrcerrorNormalize.ts:39:29)
    at ApolloServer.errorResponse (D:ProjectsPlacementHubbackendnode_modules@apolloserversrcApolloServer.ts:1028:73)
    at ApolloServer.executeHTTPGraphQLRequest (D:ProjectsPlacementHubbackendnode_modules@apolloserversrcApolloServer.ts:1020:19)

Michel FloydMichel Floyd 18.9k4 gold badges25 silver badges40 bronze badges · Accepted Answer · 2022-10-28 18:43:42Z

0

I suspect that GraphQLError has a mandatory 2nd argument and Apollo isn’t handling it well if it’s omitted.

try

throw new GraphQLError('"No user found', {
  extensions: {
    code: 'UNKNOWN_USER',
  },
});

answered Oct 28, 2022 at 18:43

Michel Floyd

18.9k4 gold badges25 silver badges40 bronze badges

umutyerebakmazumutyerebakmaz 9378 silver badges18 bronze badges · Accepted Answer · 2023-10-05 14:56:12Z

I experienced similar problems when I switched from v3 to v4. If you want to show custom errors in the resolver, using GraphQLError is enough.

In the past, it tolerated throw new Error usage. This behavior no longer works like it used to. You have to use GraphQLError instead. If you throw new Error like the past, your server will stop working.

Package versions that I have tested and are compatible with:

"graphql": "16.8.1",
"@apollo/server": "4.9.4",
"express": "4.18.2",

GraphQL has three different error types:

Syntax errors (e.g., a query was malformed)
Validation errors (e.g., a query included a schema field that doesn’t exist)
Resolver errors (e.g., an error occurred while attempting to populate
a query field)

I hope I helped you. You can review the documentation for more information. By the way, it would be beneficial for you to consider the NodeJS version separately.

throw new GraphQLError('Invalid argument value', {
    extensions: {
        code: 'BAD_USER_INPUT',
    },
});

https://www.apollographql.com/docs/react/data/error-handling

Furkan GulsenFurkan Gulsen 1,3942 gold badges12 silver badges24 bronze badges · Accepted Answer · 2022-10-28 06:47:19Z

-3

You should use ApolloError for this.


import { ApolloError } from 'apollo-server-express';

throw new ApolloError("there is a big problem");

I did the one for Express in the above line of code. You can download other packages according to your project.

answered Oct 28, 2022 at 6:47

Furkan Gulsen

1,3942 gold badges12 silver badges24 bronze badges

2

Yeahh but in V4 they have removed Apollo Error?

– Vishvaa Kesav

Oct 28, 2022 at 13:39
Probably yes, apolloError removed

– Furkan Gulsen

Oct 28, 2022 at 16:35

How To Throw Errors In Apollo Server v4?