diff --git a/lib/include/assert.sh b/lib/include/assert.sh
new file mode 100644
index 0000000..1be9973
--- /dev/null
+++ b/lib/include/assert.sh
@@ -0,0 +1,18 @@
+# compare two strings and ensure they match or crash
+# matching node order of actual, expected, [message]  https://nodejs.org/api/assert.html#assertequalactual-expected-message
+# matching rust order of actual, expexted https://users.rust-lang.org/t/assert-eq-expected-and-actual/20304/3
+#
+# @param actual
+# @param expected
+# @param [message]
+assert_eq() {
+	local actual="$1"
+	local expected="$2"
+	local message="${3:-}"
+	[ "$actual" = "$expected" ] && return
+
+	printf 'assertion error! %s\n' "$message" 1>&2
+	printf ' expected: %s\n' "$expected" 1>&2
+	printf '      got: %s\n' "$actual" 1>&2
+}
+
diff --git a/lib/include/tw_config.sh b/lib/include/tw_config.sh
index 09b1579..956bf1c 100644
--- a/lib/include/tw_config.sh
+++ b/lib/include/tw_config.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+source lib/include/assert.sh
+
 twcfg_line=0
 twcfg_last_line="firstline"
 
@@ -205,6 +207,16 @@ function twcfg.include_exec() {
 	done < "$config"
 }
 
+# usage: get_tw_config_value LINE
+# given one config value line it extracts only the value
+# stripping of the config key and comments
+function get_tw_config_value() {
+	local line="$1"
+	printf '%s' "$line" | cut -d' ' -f2- | xargs
+}
+
+assert_eq "$(get_tw_config_value 'sv_name "foo"')" "foo" "simple double quotes"
+
 function get_tw_config() {
 	if [ "$#" != "2" ]
 	then
@@ -232,7 +244,7 @@ function get_tw_config() {
 	then
 		printf '%s' "$default_value"
 	else
-		printf '%s' "$found_key"
+		get_tw_config_value "$found_key"
 	fi
 }