commited trivial example

flake.nix

@@ -0,0 +1,39 @@
+{
+  description = "Example of a project that integrates nix flake with yarn.";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        node-modules = pkgs.mkYarnPackage {
+          name = "node-modules";
+          src = ./.;
+        };
+        frontend = pkgs.stdenv.mkDerivation {
+          name = "frontend";
+          src = ./.;
+          buildInputs = [pkgs.yarn node-modules];
+          buildPhase = ''
+            ln -s ${node-modules}/libexec/yarn-nix-example/node_modules node_modules
+            ${pkgs.yarn}/bin/yarn build
+          '';
+          installPhase =  ''
+          mkdir $out
+          mv dist $out/lib
+          '';
+
+        };
+      in 
+        {
+          packages = {
+            node-modules = node-modules;
+            default = frontend;
+          };
+        }
+    );
+}