How to register cypress `code-coverage` plugin with cypress v10?

Question

In cypress migration guide they mention that plugin files are no longer supported. They also mention that you need to use >=v3.10 of code-coverage plugin

I do have correct version installed, and I tried to update cypress.config.ts to:

import { defineConfig } from "cypress";

export default defineConfig({
  video: false,
  e2e: {
    setupNodeEvents(on, config) {
      // implement node event listeners here
      require('@cypress/code-coverage/task')(on, config)
      return config
    },
  },
});

but it doesn't work. What's the correct way? I believe I do have instrumenting working (I'm using @cypress/instrument-cra and see coverage object) but I don't see generated coverage files and I don't see a reset coverege step in tests

Answer 1

From your description the only step missing is the support file import.

// cypress/support/e2e.js
import '@cypress/code-coverage/support'

I also have a .babelrc with the following, but I believe you can do without it if just covering e2e tests.

{
  "plugins": ["istanbul"]
}

Let me know if that's not it, I will give you step-by-step.