refactor: streamline JWKS file caching logic in validation function

Author: wpjunior

lib/resty/libjwt/init.lua

@@ -38,18 +38,15 @@ local function _validate(params)
 
     local files_cached = cached:getInstance()
     for _, jwks_file in ipairs(params.jwks_files) do
-        local jwks_set
-        if files_cached:get(jwks_file) == nil then
+        local jwks_set = files_cached:get(jwks_file)
+        if jwks_set == nil then
             local file = _read_file(jwks_file)
             if file == nil then
                 goto continue
             end
             jwks_set = jwks_c.jwks_create(file);
             ffi.gc(jwks_set, jwks_c.jwks_free);
             files_cached:set(jwks_file, jwks_set, JWKS_CACHE_TTL)
-
-        else
-            jwks_set = files_cached:get(jwks_file)
         end
         local checker = jwks_c.jwt_checker_new();
         ffi.gc(checker, jwks_c.jwt_checker_free);