fix: fix code

kong/pdk/private/checks.lua

@@ -51,11 +51,19 @@ function checks.validate_header(name, value)
 
   local tvalue = type(value)
   if tvalue ~= "string" then
-    if tvalue == "number" or tvalue == "boolean" then
+    if tvalue == "table" then
+      for _, vv in ipairs(value) do
+        local tvv = type(vv)
+        if tvv ~= "string" then
+          error(fmt("invalid header value in array %q: got %s, " ..
+                              "expected string", name, tvv), 3)
+        end
+      end
+    elseif tvalue == "number" or tvalue == "boolean" then
       value = tostring(value)
     else
       error(fmt("invalid header value for %q: got %s, expected " ..
-                          "string, number or boolean", name, tvalue), 3)
+                          "string, number or boolean, table", name, tvalue), 3)
     end
   end
   return value

kong/pdk/response.lua

@@ -431,7 +431,7 @@ local function new(self, major_version)
       return
     end
 
-    ngx.header[name] = normalize_header(value)
+    ngx.header[name] = normalize_multi_header(value)
   end
 
 
@@ -463,7 +463,7 @@ local function new(self, major_version)
 
     validate_header(name, value)
 
-    add_header(name, normalize_header(value))
+    add_header(name, normalize_multi_header(value))
   end
 
 

spec/03-plugins/15-response-transformer/01-header_transformer_spec.lua

@@ -151,7 +151,7 @@ describe("Plugin: response-transformer", function()
       it("header rename error trace when same header was set twice", function()
         local headers = get_headers({ h1 = { "v1", "v2"}})
         header_transformer.transform_headers(conf, headers)
-        assert.same({h2 = "v1"}, headers)
+        assert.same({h2 = { "v1", "v2" }}, headers)
       end)
     end)
     describe("replace", function()