Improved error handling

Context.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"errors"
 	"io"
 	"net/http"
 	"unsafe"
@@ -12,8 +13,9 @@ const maxParams = 16
 // Context represents the interface for a request & response context.
 type Context interface {
 	Bytes([]byte) error
-	Error(int, error) error
+	Error(status int, messages ...any) error
 	Reader(io.Reader) error
+	SetStatus(status int)
 	String(string) error
 }
 
@@ -42,9 +44,20 @@ func (ctx *context) Bytes(body []byte) error {
 }
 
 // Error is used for sending error messages to the client.
-func (ctx *context) Error(status int, err error) error {
-	ctx.response.WriteHeader(status)
-	return err
+func (ctx *context) Error(status int, messages ...any) error {
+	var combined []error
+
+	for _, msg := range messages {
+		switch err := msg.(type) {
+		case error:
+			combined = append(combined, err)
+		case string:
+			combined = append(combined, errors.New(err))
+		}
+	}
+
+	ctx.SetStatus(status)
+	return errors.Join(combined...)
 }
 
 // Reader sends the contents of the io.Reader without creating an in-memory copy.
@@ -53,6 +66,11 @@ func (ctx *context) Reader(reader io.Reader) error {
 	return err
 }
 
+// SetStatus writes the header with the given HTTP status code.
+func (ctx *context) SetStatus(status int) {
+	ctx.response.WriteHeader(status)
+}
+
 // String responds with the given string.
 func (ctx *context) String(body string) error {
 	slice := unsafe.Slice(unsafe.StringData(body), len(body))

Server.go

@@ -1,7 +1,8 @@
 package server
 
 import (
-	"fmt"
+	"io"
+	"log"
 	"net/http"
 
 	"git.akyoto.dev/go/router"
@@ -34,7 +35,7 @@ func (server *Server) ServeHTTP(response http.ResponseWriter, request *http.Requ
 
 	if handler == nil {
 		response.WriteHeader(http.StatusNotFound)
-		fmt.Fprint(response, http.StatusText(http.StatusNotFound))
+		response.(io.StringWriter).WriteString(http.StatusText(http.StatusNotFound))
 		contextPool.Put(ctx)
 		return
 	}
@@ -42,7 +43,8 @@ func (server *Server) ServeHTTP(response http.ResponseWriter, request *http.Requ
 	err := handler(ctx)
 
 	if err != nil {
-		fmt.Fprint(response, err.Error())
+		response.(io.StringWriter).WriteString(err.Error())
+		log.Println(request.URL, err)
 	}
 
 	contextPool.Put(ctx)

Server_test.go

@@ -24,7 +24,11 @@ func TestRouter(t *testing.T) {
 	})
 
 	s.Get("/error", func(ctx server.Context) error {
-		return ctx.Error(http.StatusUnauthorized, errors.New("Not logged in"))
+		return ctx.Error(http.StatusUnauthorized, "Not logged in")
+	})
+
+	s.Get("/error2", func(ctx server.Context) error {
+		return ctx.Error(http.StatusUnauthorized, "Not logged in", errors.New("Missing auth token"))
 	})
 
 	s.Get("/reader", func(ctx server.Context) error {
@@ -43,6 +47,7 @@ func TestRouter(t *testing.T) {
 		{URL: "/", Status: http.StatusOK, Body: "Hello"},
 		{URL: "/blog/post", Status: http.StatusOK, Body: "Hello"},
 		{URL: "/error", Status: http.StatusUnauthorized, Body: "Not logged in"},
+		{URL: "/error2", Status: http.StatusUnauthorized, Body: "Not logged in\nMissing auth token"},
 		{URL: "/not-found", Status: http.StatusNotFound, Body: http.StatusText(http.StatusNotFound)},
 		{URL: "/reader", Status: http.StatusOK, Body: "Hello"},
 		{URL: "/string", Status: http.StatusOK, Body: "Hello"},