diff --git a/smiles.go b/smiles.go
new file mode 100644
index 0000000..7ca6743
--- /dev/null
+++ b/smiles.go
@@ -0,0 +1,7 @@
+package calculator
+
+type Smiles struct{}
+
+func (Smiles) Smile() string {
+	return ":)"
+}
diff --git a/smiles_test.go b/smiles_test.go
new file mode 100644
index 0000000..4501c83
--- /dev/null
+++ b/smiles_test.go
@@ -0,0 +1,9 @@
+package calculator
+
+import "testing"
+
+func TestSmile(t *testing.T) {
+	if got := (Smiles{}).Smile(); got != ":)" {
+		t.Fatalf("Smile() = %q", got)
+	}
+}