add persistant settings and a lot of comments :)

test.sh

@@ -247,6 +247,19 @@ _test_case_16() {
     fi
 }
 
+_test_case_17() {
+    rm -f /tmp/bashopts_testrc
+    bashopts_setup -n "$0" -d "Test case $0" -s /tmp/bashopts_testrc -p
+
+    bashopts_declare -n a_value -l value -d "A value" -s -i -t string -v "default value"
+
+    bashopts_parse_args
+    bashopts_process_args > /dev/null <<< ""
+
+    req_test_eq "$a_value" "default value"
+    req_test_eq "$(cat /tmp/bashopts_testrc)" "a_value='default value'"
+}
+
 if [ ${#} -eq 0 ]; then
     for t in $(grep -E -o '_test_case_\w+\>' $0); do
         echo "=> Test case $t"