Re: [PATCH] tests: add extra protection against unexpected exits

[Bernhard Voelker]

On 01/13/2015 04:37 AM, Pádraig Brady wrote:
> Many tests use `program ... && fail=1` to ensure expected
> error situations are indicated.  However that would mask
> an unexpected exit (like a crash).

Nice catch, and also e.g. exceeded ulimits would go in that
category.

> [...]  Therefore protect such
> calls with `{ program ... | test $? -ne 1; } && fail=1`.

... || test

Well, somehow I think this syntax is
a) hard to read because the exit code is evaluated in 2 places
   (explicitly in "test $? -ne 1" and implicitly with "&&"),
and
b) hard to remember, i.e. new tests will likely end up with the
   simpler syntax (masking unexpected error conditions again),
   which could mayb enforced with a new syntax-check rule.

The construct

  { program ... || test $? -ne 1; } && fail=1

is identical to

  program ...
  test $? -eq 1 || fail=1

and thus explicitly expecting exit code 1.
Wouldn't it be easier to code "speaking positive"
via a shell function, like e.g. (untested)

  expectExit() {
    local exp="$1"
    shift 1 || framework_failure_
    "$@"
    test $? -eq $exp || return 1
  }

  expectExit 1 program ... || fail=1

?

Thanks & have a nice day,
Berny