Bug Fixes
- compiler: sourcemap for dist-custom-elements generation (#4200) (62ad269), closes #3165
- compiler: write exports for defineCustomElement typedefs (#4194) (89cd845), closes #4093
- mock-doc: add missing properties of object returned by matchMedia (#2880) (69176f8), closes #4193
- test: fix infinite loops w/ react and @testing-library/dom (#4188) (51750a2), closes #3434