cleanup_test.sh

# Copyright 2013 Google Inc.
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shtk_import cleanup
shtk_import unittest


# Ignores all signals handled by shtk_cleanup.
#
# We have to call this on all shell instances from the beginning of our
# execution to any shells run within.  Some shells (pdksh) bubble these signals
# up which causes our tests to abort when the subshell of a test sends a SIGINT
# to itself, for example.  We seem to have no choice other than ignoring the
# signals here.
#
# Note that we cannot just "ignore" the signals with 'trap "" <signal>' because
# that prevents the subshells from redefining the signal handler: we have to set
# them to an arbitrary command.
#
# See http://www.cons.org/cracauer/sigint.html for details on the craziness
# involved.  This is all very confusing and I'm not even sure that pdksh is
# doing the right thing here; it might be a bug.
ignore_traps() {
    for code in ${_Shtk_Cleanup_Traps}; do
        trap "echo Outer shell \${$} caught signal ${code}" "${code}"
    done
}


# Ignore the signals in the test program.  See the comments in ignore_traps for
# details on why this is necessary.
ignore_traps


# Installs a cleanup handler and validates execution on exit.
#
# \param exitcode Exit code to validate.
do_register_exit_test() {
    local exitcode="${1}"; shift

    local failed=0
    (
        handler() {
            echo 'in the handler'
            return 123
        }
        shtk_cleanup_register handler
        echo 'before exiting'
        if [ ${exitcode} -ne 0 ]; then
            exit ${exitcode}
            echo 'after exiting'
        fi
    ) >out 2>err || failed="${?}"
    [ ${failed} = ${exitcode} ] \
        || fail "Cleanup handler didn't respect exit code"

    expect_command -o inline:"before exiting\nin the handler\n" cat out
    expect_command -o empty cat err
}


shtk_unittest_add_test register__exit_success
register__exit_success_test() {
    do_register_exit_test 0
}


shtk_unittest_add_test register__exit_failure
register__exit_failure_test() {
    do_register_exit_test 56
}


# Installs a cleanup handler and validates execution on signal delivery.
#
# \param uppercase_name Name of the signal to deliver in uppercase; e.g. HUP.
# \param lowercase_name Name of the signal to deliver in lowercase; e.g. hup.
do_register_signal_test() {
    local uppercase_name="${1}"; shift
    local lowercase_name="${1}"; shift

    # Ignore the signals in the subshell started by unittest.  See the comments
    # in ignore_traps for details on why this is necessary.
    ignore_traps

    # We must create a standalone script because we need the ability to deliver
    # a signal to self and accessing ${$} from subshells does not work as
    # intended.
    cat >script.sh <<EOF
shtk_import cleanup

handler() {
    echo 'in the handler'
}

main() {
    shtk_cleanup_register handler
    echo 'before signal'
    eval kill "-${uppercase_name}" \${$}
    echo 'after signal'
}
EOF
    expect_command shtk build script.sh

    if [ -n "${ZSH_VERSION+set}" -a "${uppercase_name}" = HUP ]; then
        # ZSH insists on exiting with code 1 instead of propagating the signal
        # (and thus returning 129) when it receives a SIGHUP.  I haven't found a
        # way around this and I do not see documentation on this fact... so I'm
        # assuming this might be a bug.  Therefore, mark the test as an expected
        # failure in this particular case.
        #
        # Note that we could also change the expectation below to make the test
        # pass... but then, we would be silently accepting two different
        # behaviors depending on the shell on which we run, and that's worse.
        set_expect_failure
    fi

    # We need to ignore the stderr here because, depending on the shell,
    # the stderr may contain a message with the termination reason after
    # we kill ourselves.  There is no way to suppress that particular
    # message.
    expect_command -s "signal:${lowercase_name}" \
        -o inline:"before signal\nin the handler\n" -e ignore ./script
}


shtk_unittest_add_test register__sighup
register__sighup_test() {
    do_register_signal_test HUP hup
}


shtk_unittest_add_test register__sigint
register__sigint_test() {
    do_register_signal_test INT int
}


shtk_unittest_add_test register__sigterm
register__sigterm_test() {
    do_register_signal_test TERM term
}


shtk_unittest_add_test register__many
register__many_test() {
    local failed=0
    (
        handler1() { echo 'first'; }
        handler2() { echo 'second'; }
        handler3() { echo 'third'; }
        shtk_cleanup_register handler1 handler2 handler3
        echo 'before exiting'
        exit 72
        echo 'after exiting'
    ) >out 2>err || failed="${?}"
    [ ${failed} = 72 ] || fail "Cleanup handler didn't respect exit code"

    expect_command -o inline:"before exiting\nfirst\nsecond\nthird\n" cat out
    expect_command -o empty cat err
}