add flake-compat and a default overlay for consumption in non-flake projects

.gitignore

@@ -6,3 +6,4 @@ test/**/.pnp.loader.mjs
 **/.yarn/unplugged
 **/.yarn/install-state.gz
 tsconfig.tsbuildinfo
+test/workspace/.yarn/cache

default.nix

@@ -0,0 +1,10 @@
+(import
+  (
+    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
+    fetchTarball {
+      url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }
+  )
+  { src = ./.; }
+).defaultNix

flake.nix

@@ -4,30 +4,43 @@
   inputs = {
     nixpkgs.url = github:nixos/nixpkgs/nixos-22.05;
     utils.url = github:numtide/flake-utils;
+    flake-compat ={
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
   };
 
   outputs = inputs@{ self, nixpkgs, utils, ... }:
-    utils.lib.eachDefaultSystem (system:
+    let
+      overlay = final: prev: {
+        yarnBerry = final.callPackage ./yarn.nix {};
+        yarn-plugin-yarnpnp2nix = final.callPackage ./yarnPlugin.nix {};
+        yarnpnp2nixLib = import ./lib/mkYarnPackage.nix { defaultPkgs = final; lib = final.lib; };
+      };
+    in (utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs {
           inherit system;
-          overlays = [
-            (final: prev: {
-              yarnBerry = prev.callPackage ./yarn.nix {};
-            })
-          ];
+          overlays = [overlay];
         };
       in
       rec {
         packages = {
-          yarn-plugin = pkgs.callPackage ./yarnPlugin.nix {};
-        };
-        lib = {
-          mkYarnPackagesFromManifest = (import ./lib/mkYarnPackage.nix { defaultPkgs = pkgs; lib = pkgs.lib; }).mkYarnPackagesFromManifest;
+          yarn-plugin = pkgs.yarn-plugin-yarnpnp2nix;
+          yarnBerry = pkgs.yarnBerry;
+          yarnpnp2nix-test = pkgs.writeShellApplication {
+            name = "yarnpnp2nix-test";
+            runtimeInputs = [ pkgs.jq ];
+            text = builtins.readFile ./runTests.sh;
+          };
         };
+        lib = pkgs.yarnpnp2nixLib;
         devShell = import ./shell.nix {
           inherit pkgs;
         };
       }
-    );
+    ))
+    //
+    { overlays.default = overlay; }
+  ;
 }

runTests.sh

@@ -8,23 +8,23 @@ pushd test
 
 nix eval --json .#packages.aarch64-darwin.testa.transitiveRuntimePackages
 
-nix build -L .#packages.$system.testb
+nix build -L ".#packages.$system.testb"
 ./result/bin/testb
 
-nix build -L .#packages.$system.testa
+nix build -L ".#packages.$system.testa"
 ./result/bin/testa-peer-test
 
-nix build -L .#packages.$system.testb.package
+nix build -L ".#packages.$system.testb.package"
 testbPackage=$(realpath ./result)/node_modules/testb
 
-nix build -L .#packages.$system.testb.shellRuntimeEnvironment
+nix build -L ".#packages.$system.testb.shellRuntimeEnvironment"
 runShellEnvironmentTest=$(realpath ./result)
 
-pushd $testbPackage
-$runShellEnvironmentTest/bin/testa-test
+pushd "$testbPackage"
+"$runShellEnvironmentTest/bin/testa-test"
 popd
 
-nix develop .#packages.$system.testb -c bash <<EOF
+nix develop ".#packages.$system.testb" -c bash <<EOF
 cd $testbPackage
 testa-test
 EOF