graphql/envelop/plugins/use-error-handler

[giscus[bot]]

graphql/envelop/plugins/use-error-handler

GraphQL Envelop Documentation

https://the-guild.dev/graphql/envelop/plugins/use-error-handler

[paul-vd]

The maskErrorFn seems to be maskError and the return type of MaskError is Error, but the err argument type is unknown causing type missmatches

[paul-vd]

The isGraphQLError helper has an incorrect typing, currently it would type the error as Error instead of GraphQLError

export declare function isGraphQLError(error: unknown): error is Error & {
    originalError?: Error;
};

So if you would want to create another error check to see if it has extensions errors, this would cause the typing to fail because extensions are not defined on the Error type, for example

function isGraphQLErrorExtensions(error: unknown): error is GraphQLError & {
    extensions: NonNullable<GraphQLError['extensions']>;
  } {
    return (
      isGraphQLError(error) &&
      error.extensions !== null &&
      error.extensions !== undefined &&
      typeof error?.extensions === 'object'
    );
  }

[paul-vd]

This also causes the path on the error object to not exist

[garfieldnate]

The typing has been changed to isGraphQLError(val: unknown): val is GraphQLError.

[garfieldnate]

No, I see now, GraphQLError is the same as error is Error & {originalError?: Error;};, and it's causing type issues for me while accessing extensions, as well.

[garfieldnate]

This really needs a lot more details. The type for errors is:

errors: {
    errors: readonly Error[] | readonly SerializableGraphQLErrorLike[];
    context: Readonly<DefaultContext>;
    phase: "parse" | "validate" | "context" | "execution";
}

• What do all of these fields indicate? What's the difference between Error and SerializableGraphQLErrorLike?
• What would be the default error formatting if I didn't register a plugin?
• I want to print out the entire incoming GQL query and the field that failed to resolve. Is that possible?

[garfieldnate]

If you have a custom context object configured in your createYoga and you want to access that context in your useErrorHandler, you'll want this in the first line:

    useErrorHandler((errors) => {
      const context = errors.context.contextValue as YOUR_CUSTOM_CONTEXT_TYPE;
      ...
    }