Move type assertions into tests.

web/mux.go

@@ -56,10 +56,6 @@ type Mux struct {
 	router
 }
 
-// Sanity check types
-var _ http.Handler = &Mux{}
-var _ Handler = &Mux{}
-
 // New creates a new Mux without any routes or middleware.
 func New() *Mux {
 	mux := Mux{

web/mux_test.go

@@ -6,6 +6,10 @@ import (
 	"testing"
 )
 
+// Sanity check types
+var _ http.Handler = &Mux{}
+var _ Handler = &Mux{}
+
 // There's... really not a lot to do here.
 
 func TestIfItWorks(t *testing.T) {