[MM-45991] Check and return JSON errors (#20735)

web/context.go

@@ -241,8 +241,8 @@ func (c *Context) SetInvalidRemoteClusterTokenError() {
 	c.Err = NewInvalidRemoteClusterTokenError()
 }
 
-func (c *Context) SetJSONEncodingError() {
-	c.Err = NewJSONEncodingError()
+func (c *Context) SetJSONEncodingError(err error) {
+	c.Err = NewJSONEncodingError(err)
 }
 
 func (c *Context) SetCommandNotFoundError() {
@@ -294,9 +294,9 @@ func NewInvalidRemoteClusterTokenError() *model.AppError {
 	return err
 }
 
-func NewJSONEncodingError() *model.AppError {
-	err := model.NewAppError("Context", "api.context.json_encoding.app_error", nil, "", http.StatusInternalServerError)
-	return err
+func NewJSONEncodingError(err error) *model.AppError {
+	appErr := model.NewAppError("Context", "api.context.json_encoding.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+	return appErr
 }
 
 func (c *Context) SetPermissionError(permissions ...*model.Permission) {

web/oauth.go

@@ -48,7 +48,7 @@ func authorizeOAuthApp(c *Context, w http.ResponseWriter, r *http.Request) {
 	var authRequest *model.AuthorizeRequest
 	err := json.NewDecoder(r.Body).Decode(&authRequest)
 	if err != nil || authRequest == nil {
-		c.SetInvalidParam("authorize_request")
+		c.SetInvalidParamWithErr("authorize_request", err)
 		return
 	}
 
@@ -241,7 +241,7 @@ func getAccessToken(c *Context, w http.ResponseWriter, r *http.Request) {
 	c.LogAudit("success")
 
 	if err := json.NewEncoder(w).Encode(accessRsp); err != nil {
-		mlog.Warn("Error writing response", mlog.Err(err))
+		c.Logger.Warn("Error writing response", mlog.Err(err))
 	}
 }
 

web/webhook.go

@@ -50,8 +50,15 @@ func incomingWebhook(c *Context, w http.ResponseWriter, r *http.Request) {
 	defer func() {
 		if *c.App.Config().LogSettings.EnableWebhookDebugging {
 			if c.Err != nil {
-				payload, _ := json.Marshal(incomingWebhookPayload)
-				mlog.Debug("Incoming webhook received", mlog.String("webhook_id", id), mlog.String("request_id", c.AppContext.RequestId()), mlog.String("payload", string(payload)))
+				fields := []mlog.Field{mlog.String("webhook_id", id), mlog.String("request_id", c.AppContext.RequestId())}
+				payload, err := json.Marshal(incomingWebhookPayload)
+				if err != nil {
+					fields = append(fields, mlog.NamedErr("encoding_err", err))
+				} else {
+					fields = append(fields, mlog.String("payload", string(payload)))
+				}
+
+				mlog.Debug("Incoming webhook received", fields...)
 			}
 		}
 	}()