diff --git a/feat.go b/feat.go
new file mode 100644
index 0000000..1f6c382
--- /dev/null
+++ b/feat.go
@@ -0,0 +1,11 @@
+package mypkg
+
+import "testing"
+
+func TestAddition(t *testing.T) {
+    got := Add(1, 1)
+    want := 2
+    if got != want {
+        t.Errorf("Add(1, 1) = %d; want %d", got, want)
+    }
+}