graphql-automock

⭐️ graphql-automock ⭐️

Automock GraphQL schemas for better testing.

Getting started

Simply pass your GraphQL type definitions to mockSchema and you're ready to go:

import { mockSchema } from "graphql-automock";
import { graphql } from "graphql";

const types = `
  type Query {
    recentPosts: [Post!]!
  }

  type Post {
    id: ID!
    content: String!
    likes: Int!
  }
`;

const mocked = mockSchema(types);

graphql(
  mocked,
  `
    query {
      recentPosts {
        id
        content
        likes
      }
    }
  `
);

Without any further configuration, this query will return:

{
  "data": {
    "recentPosts": [
      {
        "id": "recentPosts.0.id",
        "content": "recentPosts.0.content",
        "likes": 2
      },
      {
        "id": "recentPosts.1.id",
        "content": "recentPosts.1.content",
        "likes": 2
      }
    ]
  }
}

Deterministic mocking

To ensure that tests are reliable, the values generated by graphql-automock are 100% deterministic. The following default values are used:

• Boolean: true
• Int: 2
• Float: 3.14
• String: Path to value
• ID: Path to value
• Enum: The first enum value, sorted alphabetically by name
• Interface: The first possible implementation, sorted alphabetically by name
• Union: The first possible member type, sorted alphabetically by name
• List length: 2

Customizing mocks

Automatically mocking the entire schema with sensible, deterministic data allows test code to customize only the data that affects the test. This results in test code that is more concise and easier to understand:

test("likes count is hidden when there are no likes", () => {
  // Set up test data
  const mocked = mockSchema({
    schema: types,
    mocks: {
      Post: () => ({
        likes: 0 // Only the likes field is customized
      })
    }
  });

  // Continue with test...
});

API Reference

mockSchema

function mockSchema(schema: String | GraphQLSchema);

function mockSchema({
  schema: String | GraphQLSchema,
  mocks: { [String]: MockTypeResolverFn }
});

type MockTypeResolverFn = (source, args, context, info) => any;