Add tests for matching regex

tests.sh

@@ -32,6 +32,21 @@ exit" | ./example | grep -E "(ans =|Can't evaluate function/operator \".*\":)")
   esac
 }
 
+function match_regex() {
+  input="$1"
+  regex="$2"
+
+  output=$(echo "$input
+exit" | ./example | grep -E "(ans =|Can't evaluate function/operator \".*\":)")
+
+  if echo "$output" | egrep -q "$regex"; then
+    printf "\e[32mTest passed for input $input\e[0m\n"
+  else
+    printf "\e[31mTest failed for input $input: regex did not match\e[0m\n"
+    exit 1
+  fi
+}
+
 # Arithmetic tests
 test_eval "2 + 2" "4"
 test_eval "55 * 33" "1815"
@@ -329,5 +344,8 @@ test_eval 'weekday("2019-03-21", "invalidlocale")' 'The chosen locale is not sup
 test_eval 'weekday("2024-32-21")' 'Invalid format on the parameter(s). Please use two "yyyy-mm-dd" for dates OR two "yyyy-mm-ddTHH:MM" for date_times.'
 test_eval 'weekday("2024-09-17", "en", "one too many params")' 'Too many parameters passed to function "weekday".'
 
+# Regex match test
+match_regex 'current_time(5)' '\b([01]?[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]\b'
+
 echo "All tests passed!"