Merge pull request #17 from MatrixAI/optimise

Optimising the default.nix to produce a minimal nix package

Author: CMCDragonkai

default.nix

@@ -20,13 +20,13 @@ let
       --composition $out/default.nix \
       --nodejs-${nodeVersion}
   '';
-  devPackage = (import (node2nixDrv true) { inherit pkgs nodejs; }).package;
-  prodDeps = (
+  # the shell attribute has the nodeDependencies, whereas the package does not
+  node2nixProd = (
     (import (node2nixDrv false) { inherit pkgs nodejs; }).shell.override {
       dontNpmInstall = true;
     }
   ).nodeDependencies;
-  drv = devPackage.overrideAttrs (attrs: {
+  node2nixDev = (import (node2nixDrv true) { inherit pkgs nodejs; }).package.overrideAttrs (attrs: {
     src = src;
     dontNpmInstall = true;
     postInstall = ''
@@ -38,17 +38,21 @@ let
       # are present in `node_modules` already. It creates symlinks in
       # $out/lib/node_modules/.bin according to `bin` section in `package.json`.
       npm install
-
-      # replace dev dependencies
-      rm -rf $out/lib/node_modules/${attrs.packageName}/node_modules
-      cp -r ${prodDeps}/lib/node_modules $out/lib/node_modules/${attrs.packageName}/
-
-      # Create symlink to the deployed executable folder, if applicable
-      if [ -d "$out/lib/node_modules/.bin" ]
-      then
-          ln -s $out/lib/node_modules/.bin $out/bin
-      fi
     '';
   });
+  name = "${builtins.replaceStrings ["/" "@"] ["_" ""] node2nixDev.packageName}-${node2nixDev.version}";
+  drv = runCommandNoCC name {} ''
+    mkdir -p $out/lib/node_modules/${node2nixDev.packageName}
+    # copy only the dist and package.json
+    cp -r ${node2nixDev}/lib/node_modules/${node2nixDev.packageName}/dist $out/lib/node_modules/${node2nixDev.packageName}/
+    cp -r ${node2nixDev}/lib/node_modules/${node2nixDev.packageName}/package.json $out/lib/node_modules/${node2nixDev.packageName}/
+    # copy over the production dependencies
+    cp -r ${node2nixProd}/lib/node_modules $out/lib/node_modules/${node2nixDev.packageName}/
+    # create symlink to the deployed executable folder, if applicable
+    if [ -d "${node2nixDev}/lib/node_modules/.bin" ]; then
+      cp -r ${node2nixDev}/lib/node_modules/.bin $out/lib/node_modules/
+      ln -s $out/lib/node_modules/.bin $out/bin
+    fi
+  '';
 in
   drv