index.test.js

import 'jest';
import { withPlugins, extend } from '../index';

const PHASE_DEVELOPMENT_SERVER = 'phase-development-server';
const PHASE_PRODUCTION_SERVER = 'phase-production-server';

describe('next-compose-plugins', () => {
  it('extends a base config', () => {
    const plugin1 = jest.fn(nextConfig => ({ ...nextConfig, plugin1: true }));
    const plugin2 = jest.fn(nextConfig => ({ ...nextConfig, plugin2: true }));
    const plugin3 = jest.fn(nextConfig => ({ ...nextConfig, plugin3: true }));

    const baseConfig = withPlugins([plugin1, plugin2], {
      baseConfig: 'hello',
      foo: 'bar',
    });

    const extendedConfig = extend(baseConfig).withPlugins([plugin3], { foo: 'baz', extendedConfig: 'world' });

    expect(extendedConfig(PHASE_DEVELOPMENT_SERVER, { defaultConfig: { nextConfig: 'abc' } })).toEqual({
      plugin1: true,
      plugin2: true,
      plugin3: true,
      baseConfig: 'hello',
      extendedConfig: 'world',
      foo: 'baz',
      nextConfig: 'abc',
    });

    expect(plugin1).toHaveBeenCalledTimes(1);
    expect(plugin2).toHaveBeenCalledTimes(1);
    expect(plugin3).toHaveBeenCalledTimes(1);
  });

  it('passes the current phase to the extended config', () => {
    const plugin1 = jest.fn(nextConfig => ({ ...nextConfig, plugin1: true }));
    const plugin2 = jest.fn(nextConfig => ({ ...nextConfig, plugin2: true }));
    const plugin3 = jest.fn(nextConfig => ({ ...nextConfig, plugin3: true }));
    const plugin4 = jest.fn(nextConfig => ({ ...nextConfig, plugin4: true }));

    const baseConfig = withPlugins([
      [plugin1, [PHASE_DEVELOPMENT_SERVER]],
      [plugin2, [PHASE_PRODUCTION_SERVER]],
    ], {
      baseConfig: 'hello',
      foo: 'bar',
    });

    const extendedConfig = extend(baseConfig).withPlugins([
      [plugin3, [PHASE_DEVELOPMENT_SERVER]],
      [plugin4, [PHASE_PRODUCTION_SERVER]],
    ], { foo: 'baz', extendedConfig: 'world' });

    expect(extendedConfig(PHASE_PRODUCTION_SERVER, { defaultConfig: { nextConfig: 'abc' } })).toEqual({
      plugin2: true,
      plugin4: true,
      baseConfig: 'hello',
      extendedConfig: 'world',
      foo: 'baz',
      nextConfig: 'abc',
    });

    expect(plugin1).toHaveBeenCalledTimes(0);
    expect(plugin2).toHaveBeenCalledTimes(1);
    expect(plugin3).toHaveBeenCalledTimes(0);
    expect(plugin4).toHaveBeenCalledTimes(1);
  });

  it('extends the webpack config', () => {
    const plugin1 = jest.fn(nextConfig => ({
      ...nextConfig,
      webpack: () => {
        if (nextConfig.webpack) {
          return `changed from base ${nextConfig.webpack()}`;
        }

        return null;
      },
    }));

    const plugin2 = jest.fn(nextConfig => ({
      ...nextConfig,
      webpack: () => {
        if (nextConfig.webpack) {
          return `changed from current ${nextConfig.webpack()}`;
        }

        return null;
      },
    }));

    const baseConfig = withPlugins([plugin1]);
    const extendedConfig = extend(baseConfig).withPlugins([plugin2]);
    const result = extendedConfig(PHASE_DEVELOPMENT_SERVER, {
      defaultConfig: {
        webpack: () => 'webpack config',
      },
    });

    expect(result.webpack()).toEqual('changed from current changed from base webpack config');
    expect(plugin1).toHaveBeenCalledTimes(1);
    expect(plugin2).toHaveBeenCalledTimes(1);
  });
});