In bats, !
does not cause a test failure.
Problematic code:
#!/usr/bin/env bats
@test "test" {
# ... code
! test_file_exists
# ... more code
}
Correct code:
#!/usr/bin/env bats
@test "test" {
# ... code
run ! test_file_exists
# ... more code
}
Rationale:
Bats uses set -e
and trap ERR
to catch test failures as early as possible.
Although the return code of a !
negated command is inverted, they will never trigger errexit
, due to a bash design decision (see Related Resources).
This means that tests which use !
can never fail.
Starting with bats 1.5.0 you can use !
inside run
.
If you are still using an older bats version, you can rewrite ! <command>
to <command> && exit 1
.
Exceptions:
The return code of the last command in the test will be the exit code of the test function.
This means that you can use ! <command>
on the last line of the test and it will still fail appropriately.
However, you are encouraged to still use run !
in this case for consistency.
Related resources:
- SC2251: This ! is not on a condition and skips errexit
- Stackoverflow: Why do I need parenthesis In bash
set -e
and negated return code - bash manpage (look at
trap [-lp] [[arg] sigspec ...]
):The ERR trap is not executed [...] if the command's return value is being inverted via !