cleanups and code fixes incl templ

server/handler/request_context.go

@@ -2,6 +2,9 @@ package handler
 
 import (
 	"context"
+	"encoding/json"
+	"errors"
+	"io"
 	"net/http"
 	"time"
 )
@@ -10,6 +13,7 @@ const (
 	defaultRequestTimeout     = 2 * time.Minute
 	reportRequestTimeout      = 10 * time.Minute
 	longRunningRequestTimeout = 2 * time.Hour
+	defaultJSONBodyLimitBytes = 1 << 20 // 1 MiB
 )
 
 func withRequestTimeout(r *http.Request, timeout time.Duration) (context.Context, context.CancelFunc) {
@@ -22,3 +26,21 @@ func withRequestTimeout(r *http.Request, timeout time.Duration) (context.Context
 	}
 	return context.WithTimeout(base, timeout)
 }
+
+func decodeJSONBody(w http.ResponseWriter, r *http.Request, dst any) error {
+	if r == nil || r.Body == nil {
+		return errors.New("request body is required")
+	}
+	decoder := json.NewDecoder(http.MaxBytesReader(w, r.Body, defaultJSONBodyLimitBytes))
+	if err := decoder.Decode(dst); err != nil {
+		return err
+	}
+	var trailing any
+	if err := decoder.Decode(&trailing); err != io.EOF {
+		if err == nil {
+			return errors.New("request body must contain only one JSON object")
+		}
+		return err
+	}
+	return nil
+}