fresh process environment for each test?

[jtmoon79]

I want to be sure all of my tests succeed when run individually. That is, I want to be sure passing tests are not mistakenly passing due to side-affects from prior tests in that same run (e.g. the value of a static OnceCell would be set by test_a and then only read by test_b, potentially affecting the outcome of test_b). Can nextest run each test in a "fresh" environment?

That is, for test_a and test_b I know can run two commands $ cargo nextest run test_a and then $ cargo nextest run test_b. But I would like to run one command, like $ cargo nextest run --new-process (I made up the option --new-process). This way I'm sure test_a did not affect test_b.

I know there is --test-threads option. But it appears global side-affects from tests would remain after a test is run.

[sunshowers]

Thanks. Nextest always runs each test in its own process so your use case should work out of the box (and in fact is the only supported method). See https://nexte.st/docs/design/why-process-per-test/.