Fix Cypress code coverage

[masakudamatsu]

Problem

Cypress 10 requires @cypress/code-coverage@3.10.0.

• see https://docs.cypress.io/guides/references/migration-guide#Code-Coverage-Plugin
• Cypress 10.2 is needed for Apple Silicon machines (source)

But code-coverage@3.10.0 fails to run with the following error:

Error: Cannot find module '@cypress/code-coverage/use-browserify-istanbul'

This is a known issue: https://github.com/cypress-io/code-coverage/issues/573

Solution 1

A solution (cited in this post) is:

@cypress/code-coverage/use-browserify-istanbul reference which no longer exists in version 3.10.0 of @cypress/code-coverage.

The only thing cypress/code-coverage provides now is @cypress/code-coverage/use-babelrc, which has peer dependencies on webpack, babel-loader, babel/preset-env and babel/core.

After all those added, and babel.config.js configured under 'test' env (and added BABEL_ENV=test to package.json 'test:coverage' script that runs Cypress with coverage option, as well as GH ci.yml), things are looking good locally with .nyc_output/out.json once again generated.

Solution 2

When I set up the coverage report for Cypress, I went with the approach using use-browserify-istanbul, as described in the official readme. See cypress/plugins/index.js in my repo.

I can try an alternative approach, also described in the official readme.

Solution 3

Start from scratch: read Cypress docs on code coverage.

[masakudamatsu]

For the time being, we stop Cypress from reporting code coverage.

Before the first release, we'll investigate this issue again.