httpx: Add new redirect

2022-11-24 14:19:17 +01:00 · 2022-11-24 14:19:17 +01:00 · 8e2d2cce3e
commit 8e2d2cce3e
parent 41d41035e3
5 changed files with 123 additions and 35 deletions
--- a/pkg/httpx/errors.go
+++ b/pkg/httpx/errors.go
@ -0,0 +1,75 @@
+package httpx
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+)
+
+// ErrInterceptor intercepts errors and directly returns specific responses for them
+type ErrInterceptor struct {
+	Errors   map[error]Response
+	Fallback Response
+}
+
+// Intercept attempts to intercept the given error.
+// When err is nil, does nothing.
+//
+// When err is not nil, first attempts to find a static response in errors and respond with that.
+// Otherwise it returns the Fallback response.
+// intercepted indicates if some response was sent.
+func (ei ErrInterceptor) Intercept(w http.ResponseWriter, r *http.Request, err error) (intercepted bool) {
+	if err == nil {
+		return false
+	}
+
+	res, ok := ei.Errors[err]
+	if !ok {
+		res = ei.Fallback
+	}
+
+	res.ServerHTTP(w, r)
+	return true
+}
+
+// StatusInterceptor creates a new ErrInterceptor handling default responses.
+// If body returns err != nil, StatusInterceptor calls panic().
+func StatusInterceptor(contentType string, body func(code int, text string) ([]byte, error)) ErrInterceptor {
+	makeResponse := func(code int) (res Response) {
+		var err error
+		res.Body, err = body(code, http.StatusText(code))
+		if err != nil {
+			panic("StatusInterceptor: err != nil")
+		}
+
+		res.ContentType = contentType
+		res.StatusCode = code
+		return
+	}
+
+	return ErrInterceptor{
+		Errors: map[error]Response{
+			ErrNotFound:  makeResponse(http.StatusNotFound),
+			ErrForbidden: makeResponse(http.StatusForbidden),
+		},
+		Fallback: makeResponse(http.StatusInternalServerError),
+	}
+}
+
+// Common errors accepted by all httpx handlers
+var (
+	ErrNotFound  = errors.New("httpx: Not Found")
+	ErrForbidden = errors.New("httpx: Forbidden")
+)
+
+var (
+	textInterceptor = StatusInterceptor("text/plain", func(code int, text string) ([]byte, error) {
+		return []byte(text), nil
+	})
+	jsonInterceptor = StatusInterceptor("application/json", func(code int, text string) ([]byte, error) {
+		return json.Marshal(map[string]any{"status": text, "code": code})
+	})
+	htmlInterceptor = StatusInterceptor("text/html", func(code int, text string) ([]byte, error) {
+		return []byte(`<!DOCTYPE HTML><title>` + text + `</title>` + text), nil
+	})
+)