Version: XState v4

Quickstart

Install xstate and @xstate/test:

yarn add xstate @xstate/test@alpha

Create your test machine using createTestMachine:

import { createTestMachine } from '@xstate/test';

const machine = createTestMachine({
  initial: 'onHomePage',
  states: {
    onHomePage: {
      on: {
        SEARCH_FOR_MODEL_BASED_TESTING: 'searchResultsVisible',
      },
    },
    searchResultsVisible: {
      on: {
        CLICK_MODEL_BASED_TESTING_RESULT: 'onModelBasedTestingPage',
        PRESS_ESCAPE: 'searchBoxClosed',
      },
    },
    searchBoxClosed: {},
    onModelBasedTestingPage: {},
  },
});

Turn the machine into a test model using createTestModel

import { createTestModel } from '@xstate/test';

const model = createTestModel(machine);

Run the model in a test, passing in instructions on what to do on different states and events. For example, using Cypress:

describe('Toggle component', () => {
  /**
   * For each path generated by XState,
   * run a new test via `it`
   */
  model.getPaths().forEach((path) => {
    it(path.description, () => {
      // Run any setup before each test here

      /**
       * In environments, like Cypress,
       * that don’t support async, run plan.testSync();
       *
       * Otherwise, you can run await plan.test();
       */
      path.testSync({
        states: {
          onHomePage: () => {
            cy.visit('/');
          },
          searchResultsVisible: () => {
            cy.findByText('Model-based testing').should('be.visible');
          },
          searchBoxClosed: () => {
            cy.findByText('Model-based testing').should('not.be.visible');
          },
          onModelBasedTestingPage: () => {
            cy.url().should('include', '/model-based-testing/intro');
          },
        },
        events: {
          CLICK_MODEL_BASED_TESTING_RESULT: () => {
            cy.findByText('Model-based testing').click();
          },
          SEARCH_FOR_MODEL_BASED_TESTING: () => {
            cy.findByPlaceholderText('Search').type('Model-based testing');
          },
        },
      });

      // Run any cleanup after each test here
    });
  });
});