Add test

test/parallel.bats

@@ -5,6 +5,8 @@ bats_require_minimum_version 1.5.0
 load test_helper
 fixtures parallel
 
+BATS_TEST_TIMEOUT=10 # only intended for the short form test
+
 setup() {
   type -p parallel &>/dev/null || skip "--jobs requires GNU parallel"
   (type -p flock &>/dev/null || type -p shlock &>/dev/null) || skip "--jobs requires flock/shlock"
@@ -208,3 +210,9 @@ check_parallel_tests() { # <expected maximum parallelity>
 @test "BATS_NO_PARALLELIZE_WITHIN_FILE does not work from inside test function" {
   DISABLE_IN_TEST_FUNCTION=1 reentrant_run ! bats --jobs 2 "$FIXTURE_ROOT/must_not_parallelize_within_file.bats"
 }
+
+@test "Short form typo does not run endlessly" {
+  run bats -j2 "$FIXTURE_ROOT/../bats/passing.bats"
+  (( SECONDS < 5 ))
+  [ "${lines[1]}" = 'Invalid number of jobs: -2' ]
+}