zsh/Test/C03traps.ztst

# Tests for both trap builtin and TRAP* functions.

%prep

  setopt localtraps
  mkdir traps.tmp && cd traps.tmp

%test

  fn1() {
    trap 'print EXIT1' EXIT
    fn2() { trap 'print EXIT2' EXIT; }
    fn2
  }
  fn1
0:Nested `trap ... EXIT'
>EXIT2
>EXIT1

  fn1() {
    TRAPEXIT() { print EXIT1; }
    fn2() { TRAPEXIT() { print EXIT2; }; }
    fn2
  }
  fn1
0: Nested TRAPEXIT
>EXIT2
>EXIT1

  fn1() {
    trap 'print EXIT1' EXIT
    fn2() { trap - EXIT; }
    fn2
  }
  fn1
0:Nested `trap - EXIT' on `trap ... EXIT'
>EXIT1

  fn1() {
    TRAPEXIT() { print EXIT1; }
    fn2() { trap - EXIT; }
    fn2
  }
  fn1
0:Nested `trap - EXIT' on `TRAPEXIT'
>EXIT1

# We can't test an EXIT trap for the shell as a whole, because
# we're inside a function scope which we don't leave when the
# subshell exits.  Not sure if that's the correct behaviour, but
# it's sort of consistent.
  ( fn1() { trap 'print Function 1 going' EXIT; exit; print Not reached; }
    fn2() { trap 'print Function 2 going' EXIT; fn1; print Not reached; }
    fn2
  )
0:EXIT traps on functions when exiting from function
>Function 1 going
>Function 2 going

# $ZTST_exe is relative to the parent directory.
# We ought to fix this in ztst.zsh...
  cd ..
  $ZTST_exe -fc 'TRAPEXIT() { print Exited.; }'
0:EXIT traps on a script
>Exited.

  fn1() {
    trap
    trap 'print INT1' INT
    fn2() { trap 'print INT2' INT; trap; }
    trap
    fn2
    trap
  }
  fn1
0: Nested `trap ... INT', not triggered
>trap -- 'print INT1' INT
>trap -- 'print INT2' INT
>trap -- 'print INT1' INT

   fn1() {
    trap
    TRAPINT() { print INT1; }
    fn2() { TRAPINT() { print INT2; }; trap; }
    trap
    fn2
    trap
  }
  fn1
0: Nested `trap ... INT', not triggered
>TRAPINT () {
>	print INT1
>}
>TRAPINT () {
>	print INT2
>}
>TRAPINT () {
>	print INT1
>}

  fn1() {
    trap 'print INT1' INT
    fn2() { trap - INT; trap; }
    trap
    fn2
    trap
  }
  fn1
0: Nested `trap - INT' on untriggered `trap ... INT'
>trap -- 'print INT1' INT
>trap -- 'print INT1' INT

# Testing the triggering of traps here is very unpleasant.
# The delays are attempts to avoid race conditions, though there is
# no guarantee that they will work.  Note the subtlety that the
# `sleep' in the function which receives the trap does *not* get the
# signal, only the parent shell, which is waiting for a SIGCHILD.
# (At least, that's what I think is happening.) Thus we have to wait at
# least the full two seconds to make sure we have got the output from the
# execution of the trap.

  print 'This test takes at least three seconds...' >&8
  fn1() {
    trap 'print TERM1' TERM
    fn2() { trap 'print TERM2; return 1' TERM; sleep 2; }
    fn2 &
    sleep 1
    kill -TERM $!
    sleep 2
  }
  fn1
0: Nested `trap ... TERM', triggered on inner loop
>TERM2

  print 'This test, too, takes at least three seconds...' >&8
  fn1() {
    trap 'print TERM1; return 1' TERM
    fn2() { trap 'print TERM2; return 1' TERM; }
    fn2
    sleep 2
  }
  fn1 &
  sleep 1
  kill -TERM $!
  sleep 2
0: Nested `trap ... TERM', triggered on outer loop
>TERM1

  TRAPZERR() { print error activated; }
  fn() { print start of fn; false; print end of fn; }
  fn
  fn() {
    setopt localoptions localtraps
    unfunction TRAPZERR
    print start of fn
    false
    print end of fn
  }
  fn
  unfunction TRAPZERR
  print finish
0: basic localtraps handling
>start of fn
>error activated
>end of fn
>start of fn
>end of fn
>finish

  TRAPZERR() { print 'ERR-or!'; }
  f() { print f; false; }
  t() { print t; }
  f
  f && t
  t && f && true
  t && f
  testunset() {
    setopt localtraps
    unset -f TRAPZERR
    print testunset
    false
    true
  }
  testunset
  f
1: more sophisticated error trapping
>f
>ERR-or!
>f
>t
>t
>f
>ERR-or!
>testunset
>f
>ERR-or!

  f() {
    setopt localtraps
    TRAPWINCH() { print "Window changed.  That wrecked the test."; }
  }
  f
  f
  functions TRAPWINCH
1:Unsetting ordinary traps with localtraps.

#
# Returns from within traps are a perennial problem.
# The following two apply to returns in and around standard
# ksh-style traps.  The intention is that a return value from
# within the function is preserved (i.e. statuses set by the trap
# are ignored) unless the trap explicitly executes `return', which makes
# it return from the enclosing function.
#
  fn() { trap 'true' EXIT; return 1; }
  fn
1: ksh-style EXIT traps preserve return value

  inner() { trap 'return 3' EXIT; return 2: }
  outer() { inner; return 1; }
3: ksh-style EXIT traps can force return status of enclosing function