Custom plugin development in Cypress - Test Execution Trace

Test Overview

This test checks a custom Cypress plugin that logs a message before the test run. It verifies the plugin runs and the log appears in the console.

Test Code

Cypress

/// <reference types="cypress" />

// cypress/plugins/index.js
module.exports = (on, config) => {
  on('before:run', () => {
    console.log('Custom plugin: Test run is starting');
  });
};

// cypress/e2e/sample_spec.cy.js
describe('Custom Plugin Test', () => {
  it('should run a simple test and trigger plugin log', () => {
    cy.visit('https://example.cypress.io');
    cy.contains('type').click();
    cy.url().should('include', '/commands/actions');
  });
});

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Cypress test runner starts and loads plugins	Cypress initializes and loads cypress/plugins/index.js	-	PASS
2	Custom plugin logs message before test run	Console shows 'Custom plugin: Test run is starting'	Verify console log message appears	PASS
3	Test visits https://example.cypress.io	Browser opens example Cypress page	-	PASS
4	Test clicks on link containing text 'type'	Page navigates to /commands/actions	URL includes '/commands/actions'	PASS
5	Assertion checks URL contains '/commands/actions'	URL is https://example.cypress.io/commands/actions	cy.url().should('include', '/commands/actions')	PASS

Failure Scenario

Failing Condition: Custom plugin code has syntax error or plugin file missing

Execution Trace Quiz - 3 Questions

What does the custom plugin do before the test run?

A Logs a message to the console

B Clicks a button on the page

C Changes the URL

D Asserts the page title

Key Result

Always verify that custom plugins are loaded and their side effects (like logging) occur before running tests to ensure plugin integration works correctly.