I might be missing something, but it looks like the only reason we need to set the VUE_DEV_SERVER_URL env var for Cypress is because we don't set the baseUrl. What would you think about replacing:

'--env', `VUE_DEV_SERVER_URL=${url}`,

with:

'--config', `baseUrl=${url}`,

in @vue/cli-plugin-unit-jest/index.js?

Then in Cypress tests, we wouldn't have to write:

cy.visit(Cypress.env('VUE_DEV_SERVER_URL'))

but could instead simplify to:

cy.visit('/')