implementation of scalar functions min and max

testing/scalar-functions.test

@@ -141,4 +141,27 @@ do_execsql_test length-null {
 
 do_execsql_test length-empty-text {
   SELECT length('');
-} {0}
+} {0}
+do_execsql_test min-number {
+  select min_arr(-10,2,3)
+} {-10}
+
+do_execsql_test min-str {
+  select min_arr('b','a','z')
+} {a}
+
+do_execsql_test min-null {
+  select min_arr(null,null)
+} {}
+
+do_execsql_test max-number {
+  select max_arr(-10,2,3)
+} {3}
+
+do_execsql_test max-str {
+  select max_arr('b','a','z')
+} {z}
+
+do_execsql_test max-null {
+  select max_arr(null,null)
+} {}