vscode: support path literals in userSettings

programs.vscode.profiles.<name>.userSettings accepts either JSON settings or a path to a settings.json file. The update-check defaults were merged into userSettings before deciding whether to generate JSON or link a source file, so path values failed when Nix tried to apply // to them.

Skip those merges for path-like values and use the shared isPathLike helper for VS Code's source-or-generated JSON options so Nix paths, store path strings, and derivation outputs are handled consistently.

Fixes #7726

modules/programs/vscode/mkVscodeModule.nix

@@ -22,6 +22,7 @@ let
     optionalString
     types
     ;
+  inherit (lib.hm.strings) isPathLike;
 
   moduleName = lib.concatStringsSep "." modulePath;
 
@@ -60,15 +61,16 @@ let
 
   mergedUserSettings =
     userSettings: enableUpdateCheck: enableExtensionUpdateCheck:
-    userSettings
+    if isPathLike userSettings then
-    // lib.optionalAttrs (enableUpdateCheck == false) {
+      userSettings
-      "update.mode" = "none";
+    else
-    }
+      userSettings
-    // lib.optionalAttrs (enableExtensionUpdateCheck == false) {
+      // lib.optionalAttrs (enableUpdateCheck == false) {
-      "extensions.autoCheckUpdates" = false;
+        "update.mode" = "none";
-    };
+      }
-
+      // lib.optionalAttrs (enableExtensionUpdateCheck == false) {
-  isPath = p: builtins.isPath p || lib.isStorePath p;
+        "extensions.autoCheckUpdates" = false;
+      };
 
   transformMcpServerForVscode = name: server: {
     inherit name;
@@ -372,28 +374,26 @@ in
     home.file = lib.mkMerge (flatten [
       (mkIf (cfg.argvSettings != { }) {
         "${argvPath}".source =
-          if isPath cfg.argvSettings then
+          if isPathLike cfg.argvSettings then
             cfg.argvSettings
           else
             jsonFormat.generate "vscode-argv" cfg.argvSettings;
       })
 
       (mapAttrsToList (n: v: [
-        (mkIf ((mergedUserSettings v.userSettings v.enableUpdateCheck v.enableExtensionUpdateCheck) != { })
+        (
-          {
+          let
+            merged = mergedUserSettings v.userSettings v.enableUpdateCheck v.enableExtensionUpdateCheck;
+          in
+          mkIf (merged != { }) {
             "${configFilePath n}".source =
-              if isPath v.userSettings then
+              if isPathLike merged then merged else jsonFormat.generate "vscode-user-settings" merged;
-                v.userSettings
-              else
-                jsonFormat.generate "vscode-user-settings" (
-                  mergedUserSettings v.userSettings v.enableUpdateCheck v.enableExtensionUpdateCheck
-                );
           }
         )
 
         (mkIf (v.userTasks != { }) {
           "${tasksFilePath n}".source =
-            if isPath v.userTasks then v.userTasks else jsonFormat.generate "vscode-user-tasks" v.userTasks;
+            if isPathLike v.userTasks then v.userTasks else jsonFormat.generate "vscode-user-tasks" v.userTasks;
         })
 
         (mkIf
@@ -403,7 +403,7 @@ in
           )
           {
             "${mcpFilePath n}".source =
-              if isPath v.userMcp then
+              if isPathLike v.userMcp then
                 v.userMcp
               else
                 let
@@ -424,7 +424,7 @@ in
 
         (mkIf (v.keybindings != [ ]) {
           "${keybindingsFilePath n}".source =
-            if isPath v.keybindings then
+            if isPathLike v.keybindings then
               v.keybindings
             else
               jsonFormat.generate "vscode-keybindings" (map (lib.filterAttrs (_: v: v != null)) v.keybindings);

tests/modules/programs/vscode/default.nix

@@ -14,6 +14,7 @@ let
     mcp-integration = import ./mcp-integration.nix;
     mcp-integration-with-override = import ./mcp-integration-with-override.nix;
     update-checks = import ./update-checks.nix;
+    path-literal = import ./path-literal.nix;
     snippets = import ./snippets.nix;
     null-package = import ./null-package.nix;
     fork-package-warning = import ./fork-package-warning.nix;

tests/modules/programs/vscode/path-literal-settings.json

@@ -0,0 +1,3 @@
+{
+  "editor.fontSize": 18
+}

tests/modules/programs/vscode/path-literal.nix

@@ -0,0 +1,33 @@
+package:
+
+{
+  pkgs,
+  ...
+}:
+
+let
+  settingsPath =
+    if pkgs.stdenv.hostPlatform.isDarwin then
+      "Library/Application Support/Code/User/settings.json"
+    else
+      ".config/Code/User/settings.json";
+in
+
+{
+  programs.vscode = {
+    enable = true;
+    inherit package;
+    profiles = {
+      default = {
+        userSettings = ./path-literal-settings.json;
+        enableUpdateCheck = false;
+        enableExtensionUpdateCheck = false;
+      };
+    };
+  };
+
+  nmt.script = ''
+    assertFileExists "home-files/${settingsPath}"
+    assertFileContent "home-files/${settingsPath}" "${./path-literal-settings.json}"
+  '';
+}