fix: the returned result may be nil when max retry is exceeded (#150)

Author: spacewander

lib/resty/etcd/v3.lua

@@ -142,22 +142,26 @@ local function _request_uri(self, method, uri, opts, timeout, ignore_auth)
     local res
     if health_check.conf.retry then
         local max_retry = #self.endpoints * health_check.conf.max_fails + 1
-        for _ = 1, max_retry do
+        for i = 1, max_retry do
             res, err = http_request_uri(self, http_cli, method, uri, body, headers, keepalive)
-            if err then
-                if err == "has no healthy etcd endpoint available" then
-                    return nil, err
-                end
-                utils.log_warn(err .. ". Retrying")
-            else
+            if res then
                 break
             end
+
+            if err == "has no healthy etcd endpoint available" then
+                return nil, err
+            end
+
+            if i < max_retry then
+                utils.log_warn(err .. ". Retrying")
+            end
         end
     else
         res, err = http_request_uri(self, http_cli, method, uri, body, headers, keepalive)
-        if err then
-            return nil, err
-        end
+    end
+
+    if err then
+        return nil, err
     end
 
     if not typeof.string(res.body) then
@@ -641,22 +645,26 @@ local function request_chunk(self, method, path, opts, timeout)
     local endpoint
     if health_check.conf.retry then
         local max_retry = #self.endpoints * health_check.conf.max_fails + 1
-        for _ = 1, max_retry do
+        for i = 1, max_retry do
             endpoint, err = http_request_chunk(self, http_cli)
-            if err then
-                utils.log_warn(err .. ". Retrying")
-                if err == "has no healthy etcd endpoint available" then
-                    return nil, err
-                end
-            else
+            if endpoint then
                 break
             end
+
+            if err == "has no healthy etcd endpoint available" then
+                return nil, err
+            end
+
+            if i < max_retry then
+                utils.log_warn(err .. ". Retrying")
+            end
         end
     else
         endpoint, err = http_request_chunk(self, http_cli)
-        if err then
-            return nil, err
-        end
+    end
+
+    if err then
+        return nil, err
     end
 
     local res