bahaghari/tests: add tests derivation for flake output

Also a schema to check if the whole test suite passes which is nice.

subprojects/bahaghari/flake.nix

@@ -39,8 +39,15 @@
           )
         );
     in eachSystem systems
-      (system: {
+      (system: let
+        tests = branch: import ./tests { inherit branch system; };
+      in {
         devShells.default =
           import ./shell.nix { pkgs = import sources.nixos-stable { inherit system; }; };
+
+        checks = {
+          bahaghariLibStable = (tests "stable").libTestPkg;
+          bahaghariLibUnstable = (tests "unstable").libTestPkg;
+        };
       }) // import ./default.nix { };
 }

subprojects/bahaghari/tests/default.nix

@@ -1,11 +1,27 @@
-# This is the unit cases for our Nix project.
-{ branch ? "nixos-stable" }:
+# This is the unit cases for our Nix project. It should only require a nixpkgs
+# instance and we'll have to make it easy to test between the unstable and
+# stable version of home-manager and NixOS.
+{ branch ? "stable", system ? builtins.currentSystem }:
 
 let
   sources = import ../npins;
-  pkgs = import sources.${branch} { };
+  pkgs = import sources."nixos-${branch}" { inherit system; };
+  bahaghariLib = import ./lib { inherit pkgs; };
 in
 {
-  lib = import ./lib { inherit pkgs; };
+  lib = bahaghariLib;
+  libTestPkg =
+    pkgs.runCommand "bahaghari-lib-test"
+      {
+        testData = builtins.toJSON bahaghariLib;
+        passAsFile = [ "testData" ];
+        nativeBuildInputs = with pkgs; [
+          yajsv
+          jq
+        ];
+      }
+      ''
+        yajsv -s "${./lib/tests.schema.json}" "$testDataPath" && touch $out || jq . "$testDataPath"
+      '';
   #modules = import ./modules { inherit pkgs; };
 }

subprojects/bahaghari/tests/lib/tests.schema.json

@@ -0,0 +1,16 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "nix-lib-bahaghari Nix test object",
+  "type": "object",
+  "patternProperties": {
+    "^\\w+$": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "minItems": 0,
+      "maxItems": 0
+    },
+    "required": true
+  }
+}