Cache should not add __typename to @export-ed input variables

[OurMajesty]

Intended outcome:
Non-scalar @export-ed variables should be send to the server without adding a __typename field, because input types do not have a __typename field.

Actual outcome:
Server responds with Field "__typename" is not defined by type LessonFilter. because the $where variable has an extra __typename field added.

How to reproduce the issue:
https://codesandbox.io/s/n58767y81p

The query:

  query GetListItems($where: LessonFilter) {
    currentFilter @client @export(as: "where") {
      title_contains
      enabled
    }
    lessonCollection(where: $where) {
      items {
        title
        slug
      }
    }
  }

currentFilter in cache is like this:

{
      __typename: "LessonFilter",
      title_contains: "SDK",
      enabled: true
}

Versions
apollo-client@2.5.1 and apollo-client@2.6.0-beta.4

Workaround for me right now is to have client resolved extra field, which is @export-ed instead of the original currentFilter and clears the extra __typename.

[supercranky]

I'm having the same problem.

[OurMajesty]

According to (updated) reproduction, the error is still there with latest apollo-client 🤔

[OurMajesty]

@benjamn 2.6.2 - same error in reproduction, where's the problem? Should I recreate issue?

[Crysp]

Theirs fixes just remove __typename from query. but you should to remove __typename from resolver by yourself.

it works for me.

resolvers.js - remove from response

export const filter = (root, variables, { cache }, { field }) => {
    const data = cache.readQuery({ query: filterQuery });
    if (field.directives.some(({ name }) => name.value === 'export')) {
        delete data.filter.__typename;
    }
    return data.filter;
};

cache.js - add when writing cache

const cache = new InMemoryCache({
    dataIdFromObject: (object) => {
        // check some unique field for filter object
        if ('contractual' in object) {
            object.__typename = 'filter';
        }
        return defaultDataIdFromObject(object);
    },
});

[Jayphen]

Do we really have to manually delete the __typename from the response as above? This seems rather hacky. I don't quite understand how this PR resolved the issue.

Here is a reproduction:
https://codesandbox.io/s/using-local-state-with-gql-server-response-ouqlu

The fix at

apollo-client/packages/apollo-utilities/src/transform.ts

Line 241 in 843fd6c

// If this SelectionSet is @export-ed as an input variable, it should

does not remove the __typename from nested fields.

i.e. in this:

          filters @client @export(as: "filters") {
            priceFilters {
              value
            }

It removes the __typename from filters, but not from priceFilters.

I have been getting around it by doing this

          filters @client @export(as: "filters") {
            priceFilters @export {
              value
            }

However this also seems like a silly hack…