How do fixtures work in Cypress?

A fixture is a file, usually JSON, that holds test data. Cypress resolves the path relative to cypress/fixtures by default, so cy.fixture with users.json reads cypress/fixtures/users.json. Fixtures keep large payloads out of the test body and make the data easy to review.

describe("user list", () => {
  beforeEach(() => {
    cy.fixture("users.json").as("users");

    cy.intercept("GET", "/api/users", { fixture: "users.json" }).as("getUsers");
    cy.visit("/users");
    cy.wait("@getUsers");
  });

  it("renders every fixture user", () => {
    cy.get("@users").then((users) => {
      cy.get("[data-cy=user-row]").should("have.length", users.length);
    });
  });
});

Ways to use fixtures

• cy.fixture reads a file and yields its parsed contents
• A fixture option on cy.intercept stubs the response body
• Alias a fixture to reuse it across assertions in the same test
• Use .then to transform or parameterise fixture data before using it
• Keep fixtures small and purposeful instead of copying a production dump

Fixtures are static. If a test needs a unique value, generate it in the test or in a custom command rather than editing the file. For database-backed tests, seed through cy.task or a request, because a fixture only controls what the browser receives.