diff --git a/tests/default.nix b/tests/default.nix
new file mode 100644
index 0000000..539c82d
--- /dev/null
+++ b/tests/default.nix
@@ -0,0 +1,9 @@
+{ branch ? "nixos-stable" }:
+
+let
+  sources = import ../npins;
+  pkgs = import sources.${branch} { };
+in
+{
+  lib = import ./lib { inherit pkgs; };
+}
diff --git a/tests/lib/default.nix b/tests/lib/default.nix
new file mode 100644
index 0000000..e775297
--- /dev/null
+++ b/tests/lib/default.nix
@@ -0,0 +1,12 @@
+{ pkgs }:
+
+let
+  lib = import ../../lib { inherit pkgs; };
+  callLib = file: import file {
+    inherit (pkgs) lib; inherit pkgs;
+    self = lib;
+  };
+in
+{
+  env = callLib ./env;
+}
diff --git a/tests/lib/env/default.nix b/tests/lib/env/default.nix
new file mode 100644
index 0000000..b2da63d
--- /dev/null
+++ b/tests/lib/env/default.nix
@@ -0,0 +1,29 @@
+{ pkgs, lib, self }:
+
+lib.runTests {
+  testsBuildSampleConfiguration = {
+    expr =
+      let
+        sampleConf = self.env.build {
+          inherit pkgs;
+          modules = [ ./wrapper-neofetch.nix ];
+          specialArgs.yourMomName = "Joe Mama";
+        };
+      in
+        lib.isDerivation sampleConf.config.build.toplevel;
+    expected = true;
+  };
+
+  testsBuildSampleConfiguration2 = {
+    expr =
+      let
+        sampleConf = self.env.build {
+          inherit pkgs;
+          modules = [ ./wrapper-fastfetch.nix ];
+          specialArgs.yourMomName = "Joe Mama";
+        };
+      in
+        lib.isDerivation sampleConf.config.build.toplevel;
+    expected = true;
+  };
+}
diff --git a/tests/lib/env/wrapper-fastfetch.nix b/tests/lib/env/wrapper-fastfetch.nix
new file mode 100644
index 0000000..c7af5ab
--- /dev/null
+++ b/tests/lib/env/wrapper-fastfetch.nix
@@ -0,0 +1,7 @@
+{ lib, pkgs, ... }:
+
+{
+  arg0 = lib.getExe' pkgs.fastfetch "fastfetch";
+  appendArgs = [ "--logo" "Guix" ];
+  env.NO_COLOR = "1";
+}
diff --git a/tests/lib/env/wrapper-neofetch.nix b/tests/lib/env/wrapper-neofetch.nix
new file mode 100644
index 0000000..5092d04
--- /dev/null
+++ b/tests/lib/env/wrapper-neofetch.nix
@@ -0,0 +1,11 @@
+{ lib, pkgs, yourMomName, ... }:
+
+{
+  arg0 = lib.getExe' pkgs.neofetch "neofetch";
+  executableName = yourMomName;
+  appendArgs = [
+    "--ascii_distro" "guix"
+    "--title_fqdn" "off"
+    "--os_arch" "off"
+  ];
+}