adds custom response errors

cmd/api/errors.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func (app *application) logError(r *http.Request, err error) {
+	app.logger.Print(err)
+}
+
+func (app *application) errorResponse(w http.ResponseWriter, r *http.Request, status int, message any) {
+	env := envelope{"error": message}
+
+	err := app.writeJSON(w, status, env, nil)
+	if err != nil {
+		app.logError(r, err)
+		w.WriteHeader(500)
+	}
+}
+
+func (app *application) serverErrorResponse(w http.ResponseWriter, r *http.Request, err error) {
+	app.logError(r, err)
+
+	message := "the server encountered an error and could not process your request"
+	app.errorResponse(w, r, http.StatusInternalServerError, message)
+}
+
+func (app *application) notFoundResponse(w http.ResponseWriter, r *http.Request) {
+	message := "the requested resources could not be found"
+	app.errorResponse(w, r, http.StatusNotFound, message)
+}
+
+func (app *application) methodNotAllowedResponse(w http.ResponseWriter, r *http.Request) {
+	message := fmt.Sprintf("the %s method is not supported for this resource", r.Method)
+	app.errorResponse(w, r, http.StatusMethodNotAllowed, message)
+}