By placing a specific YAML under config/ and defining the constants, you can easily read the value.

npm install const-settings

Place the file that defines the constants in config/settings.yaml or config/settings.yml.
If you want to split the file, set YAML under config/settings/.

├── config
│   ├── settings
│   │   ├── fuga.yaml
│   │   └── piyo.yml
│   ├── settings.yaml
│   └── settings.yml
├── package-lock.json
└── package.json

const Settings = require('const-settings').default

Settings.PIYO.forEach(v => console.log(v))

import Settings from 'const-settings'

Settings.PIYO.forEach((v: string) => console.log(v))

npm run test