Template: CI Tests

The CI template is Den’s comprehensive test suite. It tests every feature using nix-unit. This is the best learning resource for understanding exactly how Den behaves.

Structure

flake.nix
modules/
  empty.nix                              # example test skeleton
  test-support/
    eval-den.nix                         # denTest + evalDen helpers
    nix-unit.nix                         # nix-unit integration
  features/
    angle-brackets.nix                   # <den/...> syntax
    conditional-config.nix               # conditional imports/configs
    default-includes.nix                 # den.default behavior
    forward.nix                          # den._.forward
    homes.nix                            # standalone HM
    host-options.nix                     # host/user schema options
    namespaces.nix                       # namespace define/merge/export
    os-user-class.nix                    # user class forwarding
    parametric.nix                       # parametric functors
    schema-base-modules.nix              # den.base modules
    special-args-custom-instantiate.nix  # custom instantiation
    top-level-parametric.nix             # top-level context aspects
    user-host-bidirectional-config.nix   # bidirectional providers
    batteries/
      define-user.nix                    # define-user battery
      flake-parts.nix                    # inputs' and self'
      import-tree.nix                    # import-tree battery
      primary-user.nix                   # primary-user battery
      tty-autologin.nix                  # tty-autologin battery
      unfree.nix                         # unfree packages
      user-shell.nix                     # user-shell battery
    context/
      apply.nix                          # ctx application
      apply-non-exact.nix               # non-exact matching
      cross-provider.nix                 # cross-provider mechanism
      custom-ctx.nix                     # custom context types
      den-default.nix                    # den.default as context
      host-propagation.nix              # full host pipeline
      named-provider.nix                # self-named providers
    deadbugs/
      _external-namespace-deep-aspect.nix
      static-include-dup-package.nix
    home-manager/
      home-managed-home.nix
      use-global-pkgs.nix
  non-dendritic/                         # non-den files for import-tree tests
  provider/                              # external namespace provider flake

Test Categories

Core Features

Test File	What It Tests
conditional-config.nix	Conditional imports using host/user attributes
default-includes.nix	den.default applying to all hosts/users
host-options.nix	Custom host attributes, hostName, aspect names
top-level-parametric.nix	Context-aware top-level aspects
parametric.nix	All parametric functors (atLeast, fixedTo, expands)

Bidirectional & Providers

Test File	What It Tests
user-host-bidirectional-config.nix	Host→user and user→host config flow
context/cross-provider.nix	Source providing config to target context
context/named-provider.nix	Self-named provider mechanism

Context System

Test File	What It Tests
context/apply.nix	Context application mechanics
context/apply-non-exact.nix	Non-exact context matching
context/custom-ctx.nix	User-defined context types with into
context/den-default.nix	den.default as a context type
context/host-propagation.nix	Full host pipeline with all contributions

Batteries

Test File	What It Tests
batteries/define-user.nix	User definition across contexts
batteries/primary-user.nix	Primary user groups
batteries/user-shell.nix	Shell configuration
batteries/unfree.nix	Unfree package predicates
batteries/tty-autologin.nix	TTY autologin service
batteries/import-tree.nix	Auto-importing class dirs
batteries/flake-parts.nix	inputs' and self' providers

Advanced

Test File	What It Tests
angle-brackets.nix	All bracket resolution paths
namespaces.nix	Local, remote, merged namespaces
forward.nix	Custom class forwarding
homes.nix	Standalone Home-Manager configs
schema-base-modules.nix	den.base.{host,user,home,conf}

Bug Regressions

Test File	What It Tests
deadbugs/static-include-dup-package.nix	Duplicate deduplication for packages/lists
deadbugs/_external-namespace-deep-aspect.nix	Deep aspect access from external flakes

External Provider

The provider/ subdirectory is a separate flake that defines a namespace provider with aspects. It’s used by the deadbugs test to verify cross-flake namespace consumption:

provider/modules/den.nix

{ inputs, ... }:
{
  imports = [ inputs.den.flakeModule  (inputs.den.namespace "provider" true) ];
  provider.tools._.dev._.editors = {
    nixos.programs.vim.enable = true;
  };
}

Running CI Tests

From the Den root against your local checkout:

nix flake check --override-input den . ./templates/ci

You can also run a single or a subset of tests using:

# You can use any attr-path bellow flake.tests after system-agnositc to run those specific tests:
nix-unit  --override-input den .  --flake ./templates/ci#.tests.systems.x86_64-linux.system-agnostic

Writing New Tests

Copy modules/empty.nix as a starting point:

{ denTest, ... }:
{
  flake.tests.my-feature = {
    test-name = denTest (
      { den, igloo, ... }:
      {
        den.hosts.x86_64-linux.igloo.users.tux = { };
        expr = /* what you get */;
        expected = /* what you expect */;
      }
    );
  };
}