diff --git a/test/test_idgen.c3 b/test/test_idgen.c3
new file mode 100644
index 0000000..d4709d5
--- /dev/null
+++ b/test/test_idgen.c3
@@ -0,0 +1,30 @@
+import std::io;
+
+alias Id = uint;
+
+fn void foo_ex(Id id)
+{
+	io::printfn("id = %d", id);
+}
+
+
+macro Id @compute_id(...)
+{
+	Id id = (Id)$$LINE.hash() ^ (Id)@str_hash($$FILE);
+	$for var $i = 0; $i < $vacount; $i++:
+		id ^= (Id)$vaconst[$i].hash();
+	$endfor
+	return id;
+}
+
+macro foo(...) => foo_ex(@compute_id($vasplat));
+
+fn int main()
+{
+	foo_ex(1234);
+	foo();
+	foo();
+	foo();
+
+	return 0;
+}
\ No newline at end of file