Added diagnostic configuration

config/default.nix

@@ -1,3 +1,4 @@
+{ lib, ... }:
 {
   # Import all your configuration modules here
   imports = [
@@ -32,14 +33,49 @@
   globals = {
     mapleader = " ";
   };
-  diagnostic.settings = {
+  diagnostic.settings =
-    virtual_lines = {
+    let
-      current_line = true;
+      diagnostic = {
+        error = " ";
+        warning = " ";
+        hint = " ";
+        info = " ";
+      };
+    in
+    {
+      virtual_lines = {
+        current_line = true;
+      };
+      virtual_text = {
+        source = "if_many";
+        prefix = lib.nixvim.mkRaw ''
+          function (diagnostic, index, total)
+            if diagnostic.severity == vim.diagnostic.severity.ERROR then
+              return "${diagnostic.error}"
+            end
+            if diagnostic.severity == vim.diagnostic.severity.WARN then
+              return "${diagnostic.warning}"
+            end
+            if diagnostic.severity == vim.diagnostic.severity.HINT then
+              return "${diagnostic.hint}"
+            end
+            if diagnostic.severity == vim.diagnostic.severity.INFO then
+              return "${diagnostic.info}"
+            end
+          end
+        '';
+      };
+      update_in_insert = true;
+      severity_sort = true;
+      signs = {
+        text = lib.nixvim.utils.toRawKeys {
+          "vim.diagnostic.severity.ERROR" = diagnostic.error;
+          "vim.diagnostic.severity.WARN" = diagnostic.warning;
+          "vim.diagnostic.severity.HINT" = diagnostic.hint;
+          "vim.diagnostic.severity.INFO" = diagnostic.info;
+        };
+      };
     };
-    virtual_text = true;
-    update_in_insert = true;
-    severity_sort = true;
-  };
   extraConfigLua = ''
     vim.keymap.set("n", "<leader>pb", ":Pick buffers<CR>", {desc = "Pick buffers"})
     vim.keymap.set("n", "<leader>pd", ":Pick diagnostic<CR>", {desc = "Pick diagnostic"})