Mocks plugin

Replace selected field resolvers when building a schema for tests or local development. Mocks are configured per toSchema() call, so the same builder can produce mocked and unmocked schemas.

Usage

Install

npm install --save @pothos/plugin-mocks

Setup

import SchemaBuilder from '@pothos/core';
import MocksPlugin from '@pothos/plugin-mocks';
const builder = new SchemaBuilder({
  plugins: [MocksPlugin],
});

Adding mocks

You can mock any field by adding a mock in the options passed to builder.toSchema under mocks.{typeName}.{fieldName}.

builder.queryType({
  fields: (t) => ({
    greeting: t.string({
      resolve: () => {
        throw new Error('Not implemented');
      },
    }),
    untouched: t.string({ resolve: () => 'Original resolver' }),
  }),
});

export const schema = builder.toSchema({
  mocks: {
    Query: {
      greeting: () => 'Mock result!',
    },
  },
});

A mock resolver receives the usual parent, args, context, and info arguments. Configured mocks replace their field resolvers whenever those fields execute; unlisted fields keep their original resolvers. Without a mocks option, the original greeting resolver throws its error. A schema can be built multiple times with different mocks.

Adding mocks for subscribe functions

To add a mock for a subscriber you can nest the mocks for subscribe and resolve in an object. Subscription execution uses GraphQL's subscribe() in a server or test:

builder.subscriptionType({
  fields: (t) => ({
    someField: t.string({
      resolve: () => {
        throw new Error('Not implemented');
      },
      subscribe: () => {
        throw new Error('Not implemented');
      },
    }),
  }),
});

builder.toSchema({
  mocks: {
    Subscription: {
      someField: {
        resolve: (event) => event,
        subscribe: async function* () {
          yield 'First event';
          yield 'Second event';
        },
      },
    },
  },
});