test utils (#581)

Reviewed-on: fediversity/fediversity#581

.forgejo/workflows/ci.yaml

@@ -14,6 +14,12 @@ concurrency:
   group: ${{ forgejo.workflow }}-${{ forgejo.event.pull_request.number || forgejo.ref }}
 
 jobs:
+  check-utils:
+    runs-on: native
+    steps:
+      - uses: actions/checkout@v4
+      - run: nix-shell --run 'nix-unit ./deployment/utils-test.nix'
+
   check-function:
     runs-on: native
     steps:

deployment/utils-test.nix

@@ -0,0 +1,89 @@
+let
+  inherit (import ../default.nix { }) pkgs;
+  inherit (pkgs.callPackage ./utils.nix { })
+    mapKeys
+    evalOption
+    toBash
+    withPackages
+    filterNull
+    withEnv
+    ;
+  inherit (pkgs) lib;
+  inherit (lib) mkOption types;
+  inherit (types) submodule;
+in
+{
+  _class = "nix-unit";
+
+  test-mapKeys = {
+    expr = mapKeys (k: "${k}${k}") { a = 1; };
+    expected = {
+      aa = 1;
+    };
+  };
+
+  test-evalOption = {
+    expr = evalOption (mkOption {
+      type = submodule {
+        options = {
+          a = mkOption { default = 3; };
+        };
+      };
+    }) { };
+    expected = {
+      a = 3;
+    };
+  };
+
+  test-toBash-int = {
+    expr = toBash 1;
+    expected = "1";
+  };
+
+  test-toBash-null = {
+    expr = toBash null;
+    expected = "";
+  };
+
+  test-toBash-attrs = {
+    expr = toBash { a = 1; };
+    expected = ''{\"a\":1}'';
+  };
+
+  test-toBash-str = {
+    expr = toBash "'b\"";
+    expected = "'b\\\"";
+  };
+
+  test-withPackages = {
+    expr = withPackages [ pkgs.hello ];
+    expected = {
+      makeWrapperArgs = [
+        "--prefix"
+        "PATH"
+        ":"
+        "${lib.makeBinPath [ pkgs.hello ]}"
+      ];
+    };
+  };
+
+  test-filterNull = {
+    expr = filterNull {
+      a = 4;
+      b = null;
+    };
+    expected = {
+      a = 4;
+    };
+  };
+
+  test-withEnv = {
+    expr = withEnv {
+      a = 1;
+      b = null;
+      c = "'d\"";
+      e.f = [ "g" ];
+    };
+    expected = ''a="1" b="" c="'d\"" e="{\"f\":[\"g\"]}"'';
+  };
+}