Add stub_called_with and related functions

test/__stub_register-test.sh

@@ -0,0 +1,22 @@
+#! /usr/bin/env bash
+source "test-helper.sh"
+
+#
+# __stub_register() tests.
+#
+
+# Sets up stub index, stub call list, and adds stub to index.
+__stub_register "uname"
+__stub_register "top"
+assert 'echo ${STUB_INDEX[@]}' 'uname=0 top=1'
+assert 'echo ${STUB_INDEX[0]}' 'uname=0'
+assert 'echo ${STUB_INDEX[1]}' 'top=1'
+assert 'echo $STUB_NEXT_INDEX' "2"
+
+# Note: There seems to be no possible way to validate if a empty array
+# variable has been set, as it appears to be empty/null/undefined whatever I
+# try.
+
+
+# End of tests.
+assert_end "__stub_register()"