Cypress Tips/Tricks - Typing Environment Variables

index.d.ts

// Can import types from other files using TypeScript's typed imports functionality
type TestEnvironment = import('../utils/testEnv').TestEnvironment;

// Or you can define the types here as well in this type definition file
type ApiHost = "https://staging.api.com" | "https://testing.api.com" | string;

declare namespace Cypress {
  interface Cypress {
    // This types out our Cypress.env("key") calls better
    env(key: 'apiHost'): ApiHost | undefined;
    env(key: 'testEnv'): TestEnvironment | undefined;
  }
}