Can I mix different extensions of files on the configuration directory on node.js?

In the config directory of my application I have these files:

/config
 custom-environment-variables.json
 default.yaml
 production.yaml
 development.yaml

I need a configuration of the test of the app so I created a file test.json to the config directory. When I build the app I got this error:

Configuration property "sqlite" is not defined

So I change the extension of the file test.json to test.yaml and make some change. The build of the project runs successfully. I found Configuration-Files and it mentions different extensions. So my question is why the problem occurs when I create a config file with json extension and pass with yaml extension. Is it possible to mix the extensions of files in the config directories or not?

I maintain the node-config module. Yes, mixing extensions is supported. I have used it for years. Your problem is elsewhere.