lib: init builder for XDG desktop entry

lib/builders.nix

@@ -39,4 +39,33 @@
       text = lib.generators.toINI { } config;
       destination = "/share/xdg-desktop-portal/${lib.optionalString (desktopName != "common") "${desktopName}-"}portals.conf";
     };
+
+  /* Create an XDG desktop entry file. Unlike the `makeDesktopItem`, it doesn't
+     have a required schema as long as it is valid data to be converted to.
+     Furthermore, the validation process can be disabled in case you want to
+     create something like an entry for a desktop session.
+  */
+  makeXDGDesktopEntry = {
+    name,
+    config,
+    validate ? true,
+    destination ? "/share/applications/${name}.desktop",
+  }:
+    pkgs.writeTextFile {
+      name = "xdg-desktop-entry-${name}";
+      text = lib.generators.toINI {
+        listsAsDuplicateKeys = false;
+        mkKeyValue = lib.generators.mkKeyValueDefault {
+          mkValueString = v:
+            if lib.isList v then lib.concatStringsSep ";" v
+            else lib.generators.mkValueStringDefault { } v;
+        } "=";
+      } config;
+      inherit destination;
+      checkPhase =
+        lib.optionalString validate
+          ''
+            ${lib.getExe' pkgs.desktop-file-utils "desktop-file-validate"} "$target"
+          '';
+    };
 }

tests/lib/builders.nix

@@ -64,4 +64,42 @@ lib.runTests {
     expected =
       builtins.readFile ./data/fixtures/xdg-portal.conf;
   };
+
+  # We're just testing out if the destination is correct at this point.
+  testsBuilderMakeSampleXDGDesktopEntry = {
+    expr =
+      let
+        xdgDesktopEntry = self.builders.makeXDGDesktopEntry {
+          name = sampleDesktopName;
+          validate = false;
+          config = {
+            "Desktop Entry".Exec = "Hello";
+          };
+        };
+      in
+        builtins.readFile "${xdgDesktopEntry}/share/applications/${sampleDesktopName}.desktop";
+    expected =
+      builtins.readFile ./data/fixtures/xdg-desktop-entry.desktop;
+  };
+
+  # We're just testing out if the destination is correct at this point.
+  testsBuilderMakeSampleDesktopSessionFile = {
+    expr =
+      let
+        xdgDesktopEntry = self.builders.makeXDGDesktopEntry {
+          name = sampleDesktopName;
+          validate = false;
+          destination = "/share/wayland-sessions/${sampleDesktopName}.desktop";
+          config = {
+            "Desktop Entry" = {
+              Exec = "Hello";
+              DesktopNames = [ "GNOME" "Sway" ];
+            };
+          };
+        };
+      in
+        builtins.readFile "${xdgDesktopEntry}/share/wayland-sessions/${sampleDesktopName}.desktop";
+    expected =
+      builtins.readFile ./data/fixtures/xdg-desktop-session.desktop;
+  };
 }

tests/lib/data/fixtures/xdg-desktop-entry.desktop

@@ -0,0 +1,2 @@
+[Desktop Entry]
+Exec=Hello

tests/lib/data/fixtures/xdg-desktop-session.desktop

@@ -0,0 +1,3 @@
+[Desktop Entry]
+DesktopNames=GNOME;Sway
+Exec=Hello