Version Details and Security Vulnerabilities

Jest Environment JSDOM version 27.0.0 represents a significant update compared to its predecessor, version 26.6.2, primarily driven by advancements within the Jest ecosystem. While both versions maintain the MIT license and are housed within the Facebook's Jest repository, several key dependencies have been bumped to newer iterations. Notably, core Jest-related packages like jest-mock, jest-util, @jest/types, @jest/environment, and @jest/fake-timers are upgraded from version 26.6.2 to versions in the 27.0.0 range, specifically ^27.0.0-next.10 or ^27.0.0-next.11 in some cases.

This means version 27.0.0 takes a step into the upcoming Jest 27 release, introducing potential breaking changes or new features associated with those core package updates. Developers should carefully review the Jest 27 changelog and release notes to understand the implications of these dependency updates, especially if relying on specific behaviors of the mocked modules, utilities, or environment functionalities. The jsdom dependency remains at ^16.4.0 in both versions, suggesting stability in that area. The @types/node dependency also remains unchanged as a wildcard, continually pulling in the latest type definitions. jest-environment-jsdom provides a test environment that simulates a browser environment, this update also upgrades the tools necessary to make that happen. Finally, the unpacked size of version 27.0.0 is slightly smaller than that of version 26.6.2.