Right now documentation suggest fields like this in the jest.config: link
transform<span>: </span><span>{<br></span> <span>".(css|scss|sass|less)$"</span><span>: </span><span>"<rootDir>/style-mock.ts"</span><span>,</span><span><br></span><span>},</span>
I suggest to add another transform:
<span>"^.+</span><span>\\</span><span>.(t|j)sx?$"</span><span>: </span><span>[</span><span>"ts-jest"</span><span>, { </span>isolatedModules<span>: true </span><span>}],</span>
It might sharply decrease the execution time of jest tests.
In our case, this change reduces execution time from 20-40s* to 10s (34 test suites, 140 tests on Apple m1 chip)
* 40s only in case when jest runs tests without starting from the slowest one. Usually it takes 20-25s