The documentation for this library mentions that it follows the dotenv-flow for multi-environment variable loading. (link)

However, I've noticed a minor difference when compared to the dotenv-flow.
According to the dotenv-flow's variables overwriting priority, the variable merging order should be:

1. .env
2. .env.local
3. .env.development
4. .env.development.local
5. Command line variables

But in practice, when NODE_ENV='development', the order of variable merging in this library seems to be:

1. .env
2. .env.development
3. .env.local
4. .env.development.local
5. Command line variables

This had lead some confusions, for instance, mode-specific variables being unexpectedly overwritten by variables from the .env.local file.