vscode: add user tasks (#2804)

modules/programs/vscode.nix

@@ -28,6 +28,7 @@ let
     "${config.xdg.configHome}/${configDir}/User";
 
   configFilePath = "${userDir}/settings.json";
+  tasksFilePath = "${userDir}/tasks.json";
   keybindingsFilePath = "${userDir}/keybindings.json";
 
   # TODO: On Darwin where are the extensions?
@@ -70,6 +71,27 @@ in {
         '';
       };
 
+      userTasks = mkOption {
+        type = jsonFormat.type;
+        default = { };
+        example = literalExpression ''
+          {
+            "version": "2.0.0",
+            "tasks": [
+              {
+                "type": "shell",
+                "label": "Hello task",
+                "command": "hello",
+              }
+            ]
+          }
+        '';
+        description = ''
+          Configuration written to Visual Studio Code's
+          <filename>tasks.json</filename>.
+        '';
+      };
+
       keybindings = mkOption {
         type = types.listOf (types.submodule {
           options = {
@@ -146,6 +168,10 @@ in {
         "${configFilePath}".source =
           jsonFormat.generate "vscode-user-settings" cfg.userSettings;
       })
+      (mkIf (cfg.userTasks != { }) {
+        "${tasksFilePath}".source =
+          jsonFormat.generate "vscode-user-tasks" cfg.userTasks;
+      })
       (mkIf (cfg.keybindings != [ ])
         (let dropNullFields = filterAttrs (_: v: v != null);
         in {