Setting up helix LSPs more reproducibly

nix/home/programs/helix/default.nix

@@ -1,4 +1,8 @@
 { pkgs, ...}:
+let
+  # We need a version of vscode-language-servers that's less than 4.10
+  oldNixpkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/f68797befe20fc56153363e71ea0f0b74542db4b.tar.gz") {};
+in
 {
   programs.helix = {
     enable = true;
@@ -9,10 +13,29 @@
         };
 
         typescript-language-server = {
-          command = "typescript-language-server";
+          command = "${pkgs.typescript-language-server}/bin/typescript-language-server";
           args = [ "--stdio" ];
           config.hostInfo = "helix";
         };
+
+        eslint = {
+          command = "${oldNixpkgs.nodePackages.vscode-langservers-extracted}/bin/vscode-eslint-language-server";
+          args = ["--stdio"];
+          config = {
+            run = "onType";
+            validate = "on";
+            nodePath = "";
+            rulesCustomizations = [];
+            workingDirectory.mode = "location";
+            showDocumentation.enable = true;
+            experimental = { useFlatConfig = false; };
+            problems = { shortenToSingleLine = false; };
+            codeAction = {
+              enable = true;
+              location = "separateLine";
+            };
+          };
+        };
       };
 
       language = [
@@ -25,11 +48,13 @@
         }
         {
           name = "typescript";
+          file-types = [ "tsx" "ts" ];
           auto-format = true;
+          formatter = { command = "prettier"; args = ["--parser=typescript"]; };
           language-servers = [
+            { name = "eslint"; }
             {
               name = "typescript-language-server";
-              except-features = [ "format" "diagnostics" ];
             }
           ];
         }
@@ -45,6 +70,7 @@
           normal = "block";
           select = "block";
         };
+        bufferline = "multiple";
       };
       keys = {
         normal = {
@@ -52,7 +78,6 @@
           "ret" = [ "move_line_down" "goto_first_nonwhitespace" ]; # Maps the enter key to move to start of next line
           X = "extend_line_above";
           D = "delete_char_backward";
-          ";" = "command_mode"; # Note: this shadows the normal use of ";", which is to reset the selection to the cursor.
           "S-ret" = [ "move_line_up" "goto_first_nonwhitespace" ];
         };
         insert = {