Improve error reporting

handler/mastodon/authorizer.go

@@ -15,7 +15,7 @@ import (
 // JWT token was created for a particular OAuth client and is not a regular User token
 func Authorizer(serverFactory *server.Factory) toot.Authorizer[model.Authorization] {
 
-	const location = "handler.mastodon_Authorization"
+	const location = "handler.mastodon.Authorizater"
 
 	return func(request *http.Request) (model.Authorization, error) {
 

service/jwt.go

@@ -114,14 +114,20 @@ func (service *JWT) ParseString(tokenString string) (*jwt.Token, error) {
 
 	const location = "service.JWT.ParseString"
 
-	claims := model.NewAuthorization()
+	// RULE: JWT token must not be empty
+	if tokenString == "" {
+		return nil, derp.NewBadRequestError(location, "JWT token is empty")
+	}
 
+	// Try to parse the JWT token
+	claims := model.NewAuthorization()
 	result, err := jwt.ParseWithClaims(tokenString, &claims, service.FindKey, jwt.WithValidMethods([]string{"HS256", "HS384", "HS512"}))
 
 	if err != nil {
-		return nil, derp.Wrap(err, location, "Error parsing JWT token")
+		return nil, derp.Wrap(err, location, "Error parsing JWT token", tokenString)
 	}
 
+	// Success.
 	return result, nil
 }