Enforce flat flake inputs. That is, all inputs are explicitly specified at the top-level or explicitly allowed.

Just run,

nix run github:linyinfeng/flat-flake -- check FLAKE

To explicitly allow non-top-level inputs, add these input paths to outputs.flatFlake.allowed, e.g. to add flake-utils/system:

{
  outputs = {...}: {
    flatFlake = {
      allowed = [
        ["flake-utils" "systems"]
      ];
    };
  };
}

Use check --lock-file /path/to/flake.lock to read lock contents directly from a file instead of calling nix flake metadata --json.

Use check --config-file /path/to/flat-flake.json to read configuration directly from a file instead of calling nix eval flake#flatFlake --json.

flat-flake.json example:

{
  "allowed": [
    ["flake-utils", "systems"]
  ]
}

Use --help to get help information.

Just import github:linyinfeng/flat-flake#flakeModules.flat-flake. The module will create checks.${system}.flat-flake for you.

To set flat flake configuration, use the flatFlake.config option. Set flatFlake.check.enable = false to disable check generation. Set flatFlake.output.enable = false to disable configuration output.

Read flake-module.nix for more information.