# Cypress v4.2.0 — Release & Upgrade Intelligence
- **Product:** Cypress (https://www.cypress.io)
- **Version:** v4.2.0
- **Released:** Mar 16, 2020
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/cypress/updates/v4.2.0/

## Executive Summary (TL;DR)
Cypress v4.2.0. Source highlight: *Released 3/16/2020*

## New Features
- We added types for `Cypress.sinon`. Addresses #6720.
- We've added the foundational work required to support experimental features in the Test Runner. Addresses #6257.

## Bug Fixes
- We fixed a regression in 3.8.3  where HTTPS requests could experience slowdown. Fixes #6659.
- We now detect some installations of Firefox that were previously undetected. Fixes #6669.
- We fixed a race condition where an asynchronous error could fail to be caught when running the plugins file process. Fixes #6570.
- We now more thoroughly ensure the parent of an element exists when recursively calling actionability checks in order to prevent some maximum call stack errors. Fixes #6707.
- Specfiles containing `&` or `%` characters now correctly run instead of erroring. Fixes #4210.
- We added support for running tests on Jira plugins even when Jira scripts were not minified. Fixes #1436.