add nix flake

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -6,4 +6,5 @@ yarn-error.log
 *.vsix
 
 # A symbolic link to a local development kanata repo for testing changes.
-kanata-local
+kanata-local
+.direnv

flake.nix

@@ -0,0 +1,48 @@
+{
+  # testing flake: nix develop --unset PATH
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+
+    rust-overlay.url = "github:oxalica/rust-overlay/stable";
+    rust-overlay.inputs.nixpkgs.follows = "nixpkgs";
+    rust-overlay.inputs.flake-utils.follows = "flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils, rust-overlay }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ (import rust-overlay) ];
+        };
+        target = "wasm32-unknown-unknown";
+        targetUpperSnake = pkgs.lib.toUpper (builtins.replaceStrings [ "-" ] [ "_" ] target);
+        toolchainOverride = {
+          extensions = [ "rust-src" ];
+          targets = [ target ];
+        };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          RUSTC_WRAPPER = "${pkgs.sccache}/bin/sccache";
+          "CARGO_TARGET_${targetUpperSnake}_LINKER" = "${pkgs.lld_18}/bin/lld";
+          RUSTFLAGS = nixpkgs.lib.strings.concatStringsSep " " [
+            # "-C link-arg=-fuse-ld=${pkgs.mold}"
+            # "-C link-arg=--ld-path=${pkgs.mold}"
+            # "-Zlinker-features=-lld"
+          ];
+          nativeBuildInputs = with pkgs; [
+            # (rust-bin.selectLatestNightlyWith (toolchain: toolchain.default.override toolchainOverride))
+            (rust-bin.stable.latest.default.override toolchainOverride)
+            # (rust-bin.stable."1.73.0".default.override toolchainOverride)
+            just
+            git
+            yarn
+            wasm-pack
+          ];
+        };
+      }
+    );
+}

package.json

@@ -23,7 +23,7 @@
   },
   "license": "LGPL-3.0",
   "engines": {
-    "node": "^21.1.0",
+    "node": "^20.12.2",
     "vscode": "^1.80.0"
   },
   "main": "./out/client.js",