ch3.6

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 a problem 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 resource 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)
+}

cmd/api/healthcheck.go

@@ -15,6 +15,6 @@ func (app *application) healthcheckHandler(w http.ResponseWriter, r *http.Reques
 	err := app.writeJSON(w, http.StatusOK, env, nil)
 	if err != nil {
 		app.logger.Print(err)
-		http.Error(w, "The server encountered a problem and could not process your request", http.StatusInternalServerError)
+		app.serverErrorResponse(w, r, err)
 	}
 }

cmd/api/movies.go

@@ -15,7 +15,7 @@ func (app *application) createMovieHandler(w http.ResponseWriter, r *http.Reques
 func (app *application) showMovieHandler(w http.ResponseWriter, r *http.Request) {
 	id, err := app.readIDParam(r)
 	if err != nil {
-		http.NotFound(w, r)
+		app.notFoundResponse(w, r)
 		return
 	}
 
@@ -31,6 +31,6 @@ func (app *application) showMovieHandler(w http.ResponseWriter, r *http.Request)
 	err = app.writeJSON(w, http.StatusOK, envelope{"movie": movie}, nil)
 	if err != nil {
 		app.logger.Print(err)
-		http.Error(w, "The server encountered a problem and could not process your request", http.StatusInternalServerError)
+		app.serverErrorResponse(w, r, err)
 	}
 }

cmd/api/routes.go

@@ -9,6 +9,9 @@ import (
 func (app *application) routes() *httprouter.Router {
 	router := httprouter.New()
 
+	router.NotFound = http.HandlerFunc(app.notFoundResponse)
+	router.MethodNotAllowed = http.HandlerFunc(app.methodNotAllowedResponse)
+
 	router.HandlerFunc(http.MethodGet, "/v1/healthcheck", app.healthcheckHandler)
 	router.HandlerFunc(http.MethodPost, "/v1/movies", app.createMovieHandler)
 	router.HandlerFunc(http.MethodGet, "/v1/movies/:id", app.showMovieHandler)