Add specs for WinError

Author: straight-shoota

spec/std/system_error_spec.cr

@@ -22,4 +22,22 @@ describe SystemError do
       error.os_error.should eq Errno::ENOENT
     end
   end
+
+  {% if flag?(:win32) %}
+    describe ".from_winerror" do
+      it "avoid reset from message" do
+        WinError.value = :ERROR_FILE_NOT_FOUND
+        error = ::RuntimeError.from_winerror(message: "foobar".tap { WinError.value = :ERROR_ACCESS_DENIED })
+        error.os_error.should eq WinError::ERROR_ACCESS_DENIED # This should be ERROR_FILE_NOT_FOUND
+      end
+    end
+
+    describe ".from_wsa_error" do
+      it "avoid reset from message" do
+        WinError.wsa_value = :ERROR_FILE_NOT_FOUND
+        error = ::RuntimeError.from_wsa_error(message: "foobar".tap { WinError.wsa_value = :ERROR_ACCESS_DENIED })
+        error.os_error.should eq WinError::ERROR_ACCESS_DENIED # This should be ERROR_FILE_NOT_FOUND
+      end
+    end
+  {% end %}
 end