Cypress

Cypress (E2E + Component Testing)

Overview

Cypress runs browser automation with first-class network control, time-travel debugging, and a strong local dev workflow. Use it for critical path E2E tests and for component tests when browser-level rendering matters.

Quick Start

Install and open

npm i -D cypress
npx cypress open

Minimal spec

// cypress/e2e/health.cy.ts
describe("health", () => {
  it("loads", () => {
    cy.visit("/");
    cy.contains("Hello").should("be.visible");
  });
});

Core Patterns

1) Stable selectors

Prefer data-testid (or data-cy) attributes for selectors. Avoid brittle CSS chains and text-only selectors for critical interactions.

<button data-testid="save-user">Save</button>

cy.get('[data-testid="save-user"]').click();

2) Deterministic waiting (avoid fixed sleeps)

Wait on app-visible conditions or network aliases rather than cy.wait(1000).

cy.intercept("GET", "/api/users/*").as("getUser");
cy.visit("/users/1");
cy.wait("@getUser");
cy.get('[data-testid="user-email"]').should("not.be.empty");

3) Network control with cy.intercept