Breaking change from 3.0.2 to 3.1.0 [ MockedProvider ]

[tyagow]

Intended outcome:
Be able to mock a query using MockProvider

import { MockedProvider } from '@apollo/client/testing';
import { GET_TEACHERS_AND_ADMINS_OF_MY_DISTRICT_QUERY } from '../queries';

const mocks = [
  {
    request: {
      query: GET_TEACHERS_AND_ADMINS_OF_MY_DISTRICT_QUERY,
    },
    result: {
      loading: false,
      error: null,
      data: {
        teachersAndAdminsOfMyDistrict: [
          {
          [...]
...
      <MockedProvider mocks={mocks} addTypename={false}>
        <ComponentThatUsesTheQuery  />
      </MockedProvider>

Actual outcome:

After updating to 3.1.0 tests broke with:

    No more mocked responses for the query: {
      teachersAndAdminsOfMyDistrict {
      [...]

How to reproduce the issue:
Described in the first section but if more info is needed I can add here.

Versions

  System:
    OS: Linux 5.4 Ubuntu 20.04.1 LTS (Focal Fossa)
  Binaries:
    Node: 10.19.0 - /usr/bin/node
    npm: 6.14.4 - /usr/bin/npm
  Browsers:
    Chrome: 84.0.4147.105
    Firefox: 79.0
  npmPackages:
    @apollo/client: ^3.1.0 => 3.1.0 
    apollo-upload-client: ^14.1.0 => 14.1.0 

[mikevercoelen]

+1

We're also experiencing this issue

[mikevercoelen]

@tyagow as a work around, you can mock useQuery like so:

import * as Apollo from '@apollo/client';

jest.spyOn(Apollo, 'useQuery').mockImplementation(() => {
    return {
        loading: false,
        error: undefined,
        data: { MOCK_DATA },
        refetch: jest.fn()
    }
});

[tyagow]

@tyagow as a work around, you can mock useQuery like so:

import * as Apollo from '@apollo/client';

jest.spyOn(Apollo, 'useQuery').mockImplementation(() => {
    return {
        loading: false,
        error: undefined,
        data: { MOCK_DATA },
        refetch: jest.fn()
    }
});

Thank you, great idea!
In the end, I used the new mock wrapper we created that uses the schema.graphql to auto-generate responses, here is a draft:

const mergeResolvers = (target, input) => {
  const inputTypenames = Object.keys(input);
  const merged = inputTypenames.reduce(
    (accum, key) => {
      const inputResolver = input[key];
      if (target[key]) {
        const targetResolver = target[key];
        const resolvedInput = inputResolver();
        const resolvedTarget = targetResolver();
        if (
          !!resolvedTarget &&
          !!resolvedInput &&
          isDict(resolvedTarget) &&
          isDict(resolvedInput)
        ) {
          const newValue = { ...resolvedTarget, ...resolvedInput };
          return {
            ...accum,
            [key]: () => newValue,
          };
        }
      }
      return { ...accum, [key]: inputResolver };
    },
    { ...target }
  );
  return merged;
};
const buildSchema = mocks => {
  const schemaStr = print(schemaGQL) + clientDefs;
  const schema = makeExecutableSchema({
    typeDefs: schemaStr,
    resolverValidationOptions: {
      requireResolversForResolveType: false,
    },
  });

  return addMocksToSchema({ schema, mocks, preserveResolvers: true });
};

export const ApolloProviderWithMock = ({ customResolvers, client, children }) => {
  const mocks = mergeResolvers(globalMocks, customResolvers);
  const schema = buildSchema(mocks);

  let apolloClient = client;

  if (!client) {
    apolloClient = new ApolloClient({
      fetch,
      link: new SchemaLink({ schema }),
      cache: new InMemoryCache({ possibleTypes }),
      typeDefs: schema,
    });
  }

  return <ApolloProvider client={apolloClient}>{children}</ApolloProvider>;
};

Then in a test I just need to wrap the component being tested with it. Also, I can set specific values for specific queries

const customerResolver = {
  Query: () => ({
    SomeQuery: () => ({
      [...]
    })
  })
}
<ApolloProviderWithMock customerResolver={customerResolver}>
  <Component>
</ApolloProviderWithMock>

[bryancuster]

I am actually unable to get MockedProvider working at all on any 3.x version of @apollo/client.

import { render } from '@testing-library/react'
import '@testing-library/jest-dom/extend-expect'
import { MockedProvider } from '@apollo/client/testing'
import { Route, MemoryRouter } from 'react-router-dom'

...

describe('pipeline: none', () => {
  test('does not render environment section', async () => {
    const { getByText } = render(
      <MockedProvider
        mocks={[
          {
            request: {
              query: MARKETPLACE_OFFERING_QUERY,
              variables: {
                guid
              }
            },
            result: {
              data: {
                offering: { guid, name: 'mock offering' }
              }
            }
          }
        ]}
        addTypename={false}
      >
        <MemoryRouter initialEntries={['builder/123/456']}>
          <Route path="builder/:offering_guid/:plan_guid">
            <Builder />
          </Route>
        </MemoryRouter>
      </MockedProvider>
    )

    await new Promise(resolve => setTimeout(resolve, 0)) // wait for response

    expect(getByText('mock offering')).toBeInTheDocument()
  })
})

Leaving out this, the loading state is always true. With it the component is able to log out loading: true and then loading: false.

    await new Promise(resolve => setTimeout(resolve, 0)) // wait for response

The assertion fails, data is always undefined in the component even when loading: false from the useQuery.

[Markus-ipse]

My team seem to have run into the same problem :(

[unHuesio]

Same here, the mock provider seems to stopped working in some cases while running the styleguidist server, and when generating the static version of the styleguidist, some cases do work. A bit unstable, and now we are currently deciding if we should revert, or look for a solution.

[Markus-ipse]

In my case it was the same problem as described here: #6771

I added logging to my component that did the mutations and saw that the variables contained a field with an explicit undefined instead of omitting the field. So I just explicitly added undefined for the variable in my mock as well and it started working!

e.g.
From:

    {
      request: {
        query: UPDATE_ITEM,
        variables: {
          teamId: 'team-1',
          itemId: 'item-1',
        },
    },

To:

    {
      request: {
        query: UPDATE_ITEM,
        variables: {
          teamId: 'team-1',
          itemId: 'item-1',
          optionalField: undefined
        },
    },

[emmanuelkant]

In my case I added the prop like that, <MockedProvider mocks={mock} addTypename={true}> and the error stopped. I realized that the error message was with the data with __typename. Like this:

products {
  name
  description
  price
  __typename
}

So I tried this and worked for me. However, the error still is a mystery for me.

[aleksandr-omise]

Get this error - No more mocked responses for the query: mutation. Seems like MockedProvider broken or poorly documented.

[deltek-rossjackson]

I've resolved this with my post on this one

defaultOptions={{
                                watchQuery: { fetchPolicy: 'no-cache' },
                                query: { fetchPolicy: 'no-cache' },
                            }}

[joshjg]

In my case it was the same problem as described here: #6771

I added logging to my component that did the mutations and saw that the variables contained a field with an explicit undefined instead of omitting the field. So I just explicitly added undefined for the variable in my mock as well and it started working!

I found the issue to be the same as @Markus-ipse

The change in behavior appears to have been introduced here, by switching to a different deep equal function: 2593f8f#diff-fab0a81f7f7c1e746fd7f86a7a1458c9 and 26849a8
(cc: @benjamn)

The previous isEqual implementation ignored undefined object properties. Unfortunately, we were relying on that behavior so hundreds of our tests are now failing in 3.1.x.

[benjamn]

This behavior should be fixed/improved in @apollo/[email protected] (just published to npm), thanks to #7108. Please give it another try after updating!

[AdrienLemaire]

Getting the same No more mocked responses for the query error.
Bumping to 3.3.0-beta.9 didn't resolve it.
Adding defaultOptions with fetchPolicy: "no-cache" didn't help either.

example

test:

describe("ProfileHeader", () => {
  it.only("show a profile header", async () => {
    const { container } = renderApollo(<ProfileHeader />, {
      defaultOptions: {
        query: { fetchPolicy: "no-cache" },
        watchQuery: { fetchPolicy: "no-cache" },
      },
    });
    await waitFor(() => {
      expect(container).toMatchSnapshot();
    });
  });

renderApollo

import { MockedProvider, MockedResponse } from "@apollo/client/testing";

const renderApollo = (
  node: any,
  {
    mocks,
    addTypename,
    defaultOptions,
    cache,
    resolvers,
    ...options
  }: RenderApolloOptions = {}
): RenderResult => {
  return render(
    <MockedProvider
      mocks={mocks}
      addTypename={addTypename}
      defaultOptions={defaultOptions}
      cache={cache}
      resolvers={resolvers}
    >
      {node}
    </MockedProvider>,
    options
  );
};

Component:

const ProfileHeader: React.FC = () => {
  const [queryExecutor, { loading, error, data }] = useLazyQuery<TMe>(
    PROFILE_QUERY,
    {
      // fetchPolicy: "cache-only", // <!== If changing the fetchPolicy here, the test pass!
      fetchPolicy: "cache-and-network",
      nextFetchPolicy: "cache-first",
    }
  );

It would seem like MockedProvider doesn't replace my useLazyQuery options with the defaultOptions passed from the test.
Just in case, I also tried to replace useLazyQuery with useQuery, and am also getting the same error

EDIT: My issue is unrelated to this thread, sorry for the noise
While I still don't know how we're supposed to write tests for queries using fetchPolicy: "cache-and-network" (I would very much like to test the different loading phases of my component), I could get my test to pass with a jest.spy

// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
jest.spyOn(Apollo, "useLazyQuery").mockImplementation(() => {
  return [
    jest.fn(),
    {
      data: null,
      error: undefined,
      loading: false,
    },
  ];
});

[betweenparentheses]

Still experiencing this issue, even with setting fetchPolicy: no-cache, even with using the new beta version. The Dog example from the docs fails on my environment with direct copy/paste, "no more mocked responses". https://www.apollographql.com/docs/react/development-testing/testing/

worth noting that addTypename was set to FALSE but it's still expecting a __typename in one spot

UPDATE:

I was getting these errors because I had missed the necessity of cleanup between test runs.

in create-react-app, I needed

import { cleanup, render } from '@testing-library/react';


afterEach(cleanup)

FURTHER UPDATE: cleanup was not sufficient, the same specs were intermittently getting this error in CI even when passing locally. It was necessary to version bump to the beta.

[manukapoor]

This behavior should be fixed/improved in @apollo/[email protected] (just published to npm), thanks to #7108. Please give it another try after updating!

This fixes my issue @benjamn , do we have any visibility into a release schedule? This is blocking our development and it'd be great to have an estimate. Thanks!

[btferus5]

I was having this issue on any 3.x.x version (my mocks have correct variables + __typenames and all that junk, this seemed like a legitimate bug with MockedProvider), upgrading to @apollo/[email protected] did NOT fix it for me, but upgrading to @apollo/[email protected] DID fix it for me.

edit: just wanted to say that this didn't fix everything, still had some tests that were failing that definitely should pass (spent hours checking typenames + variables, 100% sure things are accurate). We had the most trouble with components that had 2 different queries running in the same file as well as queries with empty variables), it always got confused.
ended up doing this in our jest

jest.mock('@apollo/client', () => ({
...jest.requireActual('@apollo/client'),
useQuery: (query, options) => jest.requireActual('@apollo/client').useQuery(query, {
  ...options,
  fetchPolicy: 'no-cache'
  })
})
)

basically just forcing no-cache for testing purposes

[mbrowne]

The current apollo-client release is 3.3.5, and this seems to be fixed now.

[hwillson]

It doesn't sound like there is an outstanding issue here, so closing. Thanks!

[findlay-hannam]

I'm still getting this on version 3.3.21

[mbrowne]

@findlay-hannam Are you running multiple queries in a single test? Maybe you actually need to add more mocks. (But it's also possible there's still a bug somewhere.)

[findlay-hannam]

I am running multiple queries, but the tests pass when I set the fetchPolicy to 'no-cache'. I'm currently using the workaround @btferus5 suggested

[cheukribbon]

Have similar issue with fetchPolicy