Mix.Config.import_config

You're seeing just the macro import_config, go back to Mix.Config module for more information.
Link to this macro

import_config(path_or_wildcard)

View Source (macro)
This macro is deprecated. Use the Config module instead.

Imports configuration from the given file or files.

If path_or_wildcard is a wildcard, then all the files matching that wildcard will be imported; if no file matches the wildcard, no errors are raised. If path_or_wildcard is not a wildcard but a path to a single file, then that file is imported; in case the file doesn't exist, an error is raised.

If path/wildcard is a relative path/wildcard, it will be expanded relatively to the directory the current configuration file is in.

Examples

This is often used to emulate configuration across environments:

import_config "#{Mix.env()}.exs"

Or to import files from children in umbrella projects:

import_config "../apps/*/config/config.exs"