wrench is a Nix flake for quickly declaring NixOS configurations with custom packages, and tests to test those configurations.
I haven't written reference documentation yet but you can refer to iliana/nixos-configs for more in-depth usage.
flake.nix:
{
inputs = {
nixpkgs.url = "github:NixOS/nixpkgs/nixos-22.11";
wrench.url = "github:iliana/wrench";
wrench.inputs.nixpkgs.follows = "nixpkgs";
};
outputs = {wrench, ...}:
wrench.lib.generate {
packages = system: callPackage: {
hello = callPackage ./hello.nix {};
};
nixosConfigurations.x86_64-linux.ghost = {myPkgs, ...}: {
environment.systemPackages = [myPkgs.hello];
system.stateVersion = "22.11";
};
checks.x86_64-linux.hello = {
runTest,
ghost,
...
}:
runTest {
nodes = {
inherit ghost;
};
testScript = ''
stdout = ghost.succeed("hello")
assert stdout.strip() == 'Hello, world!'
'';
};
};
}hello.nix (for completeness)
{pkgs, ...}:
pkgs.writeShellApplication {
name = "hello";
text = ''
echo 'Hello, world!'
'';
}