Fail assert_exactly_one_of if it receives an odd number of arguments

Author: jeckhart

modules/bash-commons/src/assert.sh

@@ -80,6 +80,10 @@ function assert_value_in_list {
 function assert_exactly_one_of {
   local -ra args=("$@")
   local -r num_args="${#args[@]}"
+  if [[ "$((num_args % 2))" -ne 0 ]]; then
+    log_error "This script expects an even number of arguments but received $num_args instead."
+    exit 1
+  fi
 
   local num_non_empty=0
   local -a arg_names=()

test/assert.bats

@@ -184,6 +184,11 @@ load "test-helper"
   assert_failure
 }
 
+@test "assert_exactly_one_of list of length 5, with one value set, fails for odd num_args" {
+  run assert_exactly_one_of "--foo" "foo" "--bar" "" "--baz" "" "--qux"
+  assert_failure
+}
+
 @test "assert_uid_is_root_or_sudo as root" {
   run assert_uid_is_root_or_sudo
   assert_success