graphql-mock

GraphQL Client Side Mocking

This is a little library that helps with the apollo graphql projects testing. Essentially it's a wrapper over the SchemaLink to make it a bit more useful in a React app testing schenario.

At the basic level it adds two things: an option to check which queries were sent, and mock responses.

Installation & Usage

npm add -D graphq-mock

thow this somewhere in your testing environment setup

import GraphQLMock from 'graphql-mock';

const schema = `
  type Item {
    id: ID!
    name: String!
  }

  type Query {
    items: [Item]
  }
`;

// optional mocks
const mocks = {
  ... // your regular apollo mocks
};

// optional resolvers
const resolvers = {
  ... // graphql resolvers
};

export default new GraphQLMock(schema, mocks, resolvers);

Then use like so in your enzyme tests:

import { mount } from 'enzyme';
import { ApolloProvider } from 'react-apollo';
import { normalize } from 'graphql-mock';
import graphqlMock from './graphql';

import TodoList from 'src/my/component';

it('shoulda render alright', () => {
  const query = `
    query GetItems {
      items {
        id
        name
      }
    }
  `;

  graqhqlMock.expect(query).reply({
    items: [
      { id: '1', name: 'one' },
      { id: '2', name: 'two' }
    ]
  });

  const wrapper = mount(
    <ApolloProvider client={graphqlMock.client}>
      <TodoList />
    </ApolloProvider>
  );

  expect(wrapper.html()).toEqual('<ul><li>one</li><li>two</li></ul>');
  expect(graphqlMock.lastQuery).toEqual(normalize(query));
});

Testing Error States

you can test failure states by using the expect + fail combo. here are some examples

  graqhqlMock.expect(query).fail('everything is terrible');
  graqhqlMock.expect(query).fail([
    { mesage: 'everything is terrible' },
    // ...
  ]);
  graqhqlMock.expect(query).fail(new ApolloError({ .... }));

Using Existing Schema

If you have your own schema, for example to use custom resolvers, you pass a schema instance into the GraphqlMock constructor:

const typeDefs = `
`;

const resolvers = {
  // ...
};

const schema = makeExecutableSchema({ typeDefs });
const mock = new GraphqlMock(schema);

API & Stuff

#client -> a reference to the underline ApolloClient instance

#reset() -> to reset all the mocks and queries history

#queries -> the list of (string and normalized) queries that sent to the endpoint

#lastQuery -> returns the last query that sent

#requests -> requests (queries + variables) that sent to the server

#lastRequest -> return the last request that sent

#expect(query: string) -> an API to mock the exact responses

also some helper functions:

import { parse, stringify, normalize } from 'graphql-mock';

parse(query) // turns a string query into an object
stringify(query) // turns an object into a standardly formatted string query
normalize(query) // turns an object or string query into a standard formatted string query

Copyright & License

All code in this library released under the terms of the MIT license

Copyright (C) 2018 Nikolay Nemshilov