Add sourcemap support for testing

Closes #196

PiperOrigin-RevId: 195188262
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 5c23f73..00ea325 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -14,3 +14,4 @@
 Bowen Ni <bowen1897@gmail.com>
 Daniel Muller <mrmeku@gmail.com>
 Martin Probst <martin@probst.io>
+Eric Stolten <stoltene2@gmail.com>