improve native fuzz

myfuzz/myfuzz_test.go

@@ -16,20 +16,22 @@ func FuzzAuth(f *testing.F) {
 		db.Close()
 	})
 
-	f.Add("admin", "admin")
-	f.Add("user", "password")
-	f.Add("", "")
+	f.Add("admin", "admin123") // right admin
+	f.Add("user1", "password1") // right user
+	f.Add("admin", "admin") // wrong admin
+	f.Add("user", "password") // wrong user
+	f.Add("", "") // blank test
 
 	f.Fuzz(func(t *testing.T, username string, password string) {
 		ok, err := auth.Authenticate(username, password)
 		if err != nil {
-			t.Errorf("For {username} {%q} and {password} {%q} error: %v", username, password, err)
+			t.Errorf("For username %q and password %q error: %v", username, password, err)
 		}
 		if ok {
 			if (username == "admin" && password == "admin123") || (username == "user1" && password == "password1") {
 				return
 			}
-			t.Errorf("Unexpected login for {username} {%q} and {password} {%q}", username, password)
+			t.Errorf("Unexpected login for username %q and password %q", username, password)
 		}
 	})
 }