How to write mocks https://www.apollographql.com/docs/graphql-tools/mocking.html

Install

yarn global add graphql-mock-server

or

yarn add --dev graphql-mock-server

Usage

graphql-mock-server ./schema.graphql -p 4000

gms ./schema.graphql -p 4000

Basic example

import { serializedMocks } from 'graphql-mock-server';

const mock = {
  Query: () => ({
    users: () => [
      {
        id: '1',
        name: 'Foo',
      },
      {
        id: '2',
        name: 'Baz',
      },
    ],
  }),
};

const data = serializedMocks(mock);

// Set mock
fetch('http://localhost:4000/mock', {
  method: 'POST',
  body: JSON.stringify(data),
});

// Reset mock
fetch('http://localhost:4000/reset', {
  method: 'POST',
});

Accessing arguments in mock resolvers

Since the mock functions on fields are actually just GraphQL resolvers, you can use arguments and context in them as well:

{
  Query: () => ({
    // the number of friends in the list now depends on numPages
    paginatedFriends: (root, { numPages }) => new MockList(numPages * PAGE_SIZE),
  }),
}