UpdateHub / updatehub / 32293795643

70%

Build Type

push

github

Committed by otavio

Commit Message

test: route every PATH change through a guard

The tests changed `PATH` on the running process and never put it back.
`create_echo_bins` prepended its mock directory and left it there, and the
"missing binaries" tests emptied `PATH` for everyone. Since libtest runs the
tests on parallel threads, one test could make another fail: both the reboot
mock in `states::tests` and the one in `states::reboot` answer to the same name
but write to different files, so whichever prepended last won for all of them.
The 2024 edition surfaced the same problem as `unsafe`, because `setenv` races
with any concurrent read.

Split the two needs the tests actually have:

`SearchPathGuard` covers `check_requirements`, which only calls
`is_executable_in_path`. It overrides the directories that lookup reads, in a
`thread_local!`, so it writes no process state at all. libtest gives each test
its own thread and every test here uses the current-thread runtime, so the tests
no longer see each other.

`PathEnvGuard` covers the three places that run a real subprocess, where
`execvp` reads `PATH` from the process. It takes a process-wide lock, reads the
old value under that lock, and restores it on drop, including during a panic
unwind.

`create_echo_bins` now only creates the directory, and the caller picks the
guard it needs. That drops the `unsafe` writes from fourteen to one, inside
`PathEnvGuard`, and `PATH` stops leaking between tests.

Six tests cover the guards, because the old assertions passed whether or not
the lookup worked: the host has no `flash_erase` either.

Coverage Stats

150 of 156 new or added lines in 7 files covered. (96.15%)

48 existing lines in 4 files now uncovered.

2978 of 4520 relevant lines covered (65.88%)

1102.98 hits per line