tests for PoC!

tests/basic/configuration-package.nix

@@ -0,0 +1,9 @@
+{
+  runCommand,
+}: runCommand "tests-basic-configuration-dot-nix" {
+} ''
+  set -euo pipefail
+  mkdir -vp "$out/share/nixos"
+  cp -rv ${./configuration.nix} "$out/share/nixos/configuration.nix"
+  cp -rv ${../../modules/dynamicism} "$out/share/nixos/dynamicism"
+''

tests/basic/configuration.nix

@@ -0,0 +1,69 @@
+{ pkgs, lib, config, modulesPath, ... }:
+let
+  name = config.networking.hostName;
+  nixosLibPath = (modulesPath + "/../lib");
+  moduleList = import (modulesPath + "/module-list.nix");
+
+  optionalPath = p: lib.optional (builtins.pathExists p) p;
+in
+assert builtins.pathExists nixosLibPath;
+builtins.seq lib
+builtins.seq modulesPath
+builtins.seq moduleList
+{
+  imports = moduleList ++ [
+    (modulesPath + "/testing/test-instrumentation.nix")
+  ] ++ lib.concatLists [
+    (optionalPath ./hardware-configuration.nix)
+    (optionalPath ./dynamicism)
+    (optionalPath ../../modules/dynamicism)
+  ];
+
+  system.switch.enable = true;
+  documentation.enable = false;
+
+  networking.hostName = "machine";
+
+  boot.loader.grub = {
+    enable = true;
+    device = "/dev/vda";
+    forceInstall = true;
+  };
+
+  nix = {
+    package = pkgs.lixPackageSets.latest.lix;
+    nixPath = [ "nixpkgs=${pkgs.path}" ];
+
+    settings = {
+      experimental-features = [ "nix-command" "pipe-operator" ];
+      substituters = lib.mkForce [ ];
+      hashed-mirrors = null;
+      connect-timeout = 1;
+    };
+  };
+
+  services.gotosocial = {
+    enable = true;
+    setupPostgresqlDB = true;
+    settings = {
+      application-name = "gotosocial-for-${name}";
+      host = "${name}.local";
+    };
+  };
+
+  dynamicism.for.gotosocial.enable = true;
+
+  environment.pathsToLink = [ "/share" ];
+  environment.variables = {
+    "NIXOS_CONFIG" = "/etc/nixos/configuration.nix";
+  };
+
+  environment.shellAliases = {
+    ls = "eza --long --header --group --group-directories-first --classify --binary";
+  };
+  environment.systemPackages = with pkgs; [
+    eza
+    fd
+    ripgrep
+  ];
+}

tests/basic/default.nix

@@ -0,0 +1,7 @@
+/**
+ * Convenience shortcut for running this test from the command-line.
+ * Normally this test is initialized from /tests/default.nix.
+ */
+{
+  pkgs ? import <nixpkgs> { },
+}: pkgs.testers.runNixOSTest ./test.nix

tests/basic/test-script.py

@@ -0,0 +1,84 @@
+from pathlib import Path
+import shlex
+import textwrap
+from typing import cast, TYPE_CHECKING
+
+from beartype import beartype
+
+from test_driver.machine import Machine
+from test_driver.errors import RequestedAssertionFailed
+
+if TYPE_CHECKING:
+    global machine
+    machine = cast(Machine, ...)
+    assert machine.shell is not None
+
+ls = "eza -lah --color=always --group-directories-first"
+
+@beartype
+def run_log(machine: Machine, *commands: str, timeout: int | None = 60) -> str:
+    output = ""
+    for command in commands:
+        with machine.nested(f"must succeed: {command}"):
+            (status, out) = machine.execute(f"{command} | tee /dev/stderr", timeout=timeout)
+            if status != 0:
+                machine.log(f"output: {out}")
+                raise RequestedAssertionFailed(
+                    f"command `{command}` failed (exit code {status})",
+                )
+            output += out
+
+    return output
+
+@beartype
+def get_config_file() -> str:
+    machine.wait_for_unit("gotosocial.service")
+    gotosocial_pid = int(machine.get_unit_property("gotosocial.service", "MainPID"))
+    print(f"{gotosocial_pid=}")
+
+    cmdline = machine.succeed(f"cat /proc/{gotosocial_pid}/cmdline")
+    cmdline_args = cmdline.split("\0")
+
+    config_file_idx = cmdline_args.index("--config-path") + 1
+    config_file = Path(cmdline_args[config_file_idx])
+
+    machine.log(f"copying from VM: {config_file=}")
+    machine.copy_from_vm(config_file.as_posix())
+
+    config_file_path = machine.out_dir / config_file.name
+    with open(config_file_path, "r") as f:
+        return f.read()
+
+
+machine.wait_for_unit("default.target")
+assert "lix" in machine.succeed("nix --version").lower()
+
+run_log(machine, "nixos-generate-config")
+machine.succeed("mkdir -vp /etc/nixos")
+machine.succeed("cp -rv /run/current-system/sw/share/nixos/* /etc/nixos/")
+machine.succeed("env PAGER= nixos-rebuild switch --log-format raw-with-logs -v --fallback >&2")
+
+config_text = get_config_file()
+lines = config_text.splitlines()
+application_name = next((line for line in lines if line.startswith("application-name:")), None)
+assert application_name is not None, f"no 'application-name:' found in config file: {textwrap.indent(config_text, "")}"
+assert "gotosocial-for-machine" in application_name, f"'gotosocial-for-machine' should be in {application_name=}"
+
+new_app_name = "yay!"
+expr = textwrap.dedent(f"""
+    let
+        nixos = import <nixpkgs/nixos> {{ }};
+    in nixos.config.dynamicism.doChange {{
+        option = "services.gotosocial.settings.application-name";
+        value = "{new_app_name}";
+    }}
+""").strip()
+machine.succeed(rf"""
+    nix run --show-trace --log-format raw-with-logs --impure -E {shlex.quote(expr)}
+""".strip())
+
+config_file_new = get_config_file()
+lines = config_file_new.splitlines()
+
+application_name = next(line for line in lines if line.startswith("application-name:"))
+assert new_app_name in application_name, f"'{new_app_name}' should be in {application_name=}"

tests/basic/test.nix

@@ -0,0 +1,43 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+{
+  name = "nixos-test-dynamicism-main";
+
+  defaults = { ... }: { };
+
+  #node.pkgsReadOnly = false;
+
+  extraPythonPackages = p: [
+    p.beartype
+  ];
+
+  nodes.machine = { pkgs, config, ... }: {
+    imports = [ ./configuration.nix ];
+
+    system.includeBuildDependencies = true;
+    system.switch.enable = true;
+
+    virtualisation.additionalPaths = [ config.system.build.toplevel ];
+    virtualisation = {
+      memorySize = 4096;
+      cores = 4;
+      writableStore = true;
+      mountHostNixStore = true;
+      installBootLoader = true;
+    };
+
+    environment.systemPackages = let
+      configFileTree = pkgs.callPackage ./configuration-package.nix { };
+    in [
+      configFileTree
+    ];
+  };
+
+  # What's a little IFD between friends?
+  testScript = ./test-script.py
+  |> builtins.readFile;
+}