Assignment 4: tests, interface refactor, e2e suite

internal/handler/response.go

@@ -0,0 +1,17 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func writeJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+// writeError selalu mengirim error sebagai JSON (Content-Type: application/json).
+func writeError(w http.ResponseWriter, status int, msg string) {
+	writeJSON(w, status, map[string]string{"error": msg})
+}