Note: please refer to the upstream repo for a great explanation of what all this does.
Mostly, nothing. This is a forked AWS Repo that builds infrastructure to authenticate against for a CloudFront distribution.
BUT: Currently the only thing in here that is used is the code for the Lambda functions. Everything else has already been migrated to Terraform, and now lives in the Infrastructure repository.
As mentioned here, essentially just run npm install for the first time and npm run build and it will create the appropriate files in the src folders. As it stands, the only files that are deployed out of this repository are:
└── lambda-edge
├── check-auth
│ ├── bundle.js
│ ├── configuration.json
│ └── package.json
├── http-headers
│ ├── bundle.js
│ ├── configuration.json
│ └── package.json
├── parse-auth
│ ├── bundle.js
│ ├── configuration.json
│ └── package.json
├── refresh-auth
│ ├── bundle.js
│ ├── configuration.json
│ └── package.json
└── sign-out
├── bundle.js
├── configuration.json
└── package.json