- Introduced an alpha Component Test Runner with new CLI commands (cypress open ct/run ct) and removed the experimentalComponentTesting flag and old file:preprocessor event.
- Added many breaking changes to cy.intercept() (new matching order, automatic JSON parsing, removal of substring match, delay option, and route2 alias) and deprecated cy.route2().
- Updated defaults (Node 14, Electron 12, larger headless window, contextIsolation) and added new features (event hooks, middleware, req.continue, command log for uncaught errors, UI shortcuts) while fixing numerous bugs.