theoddler / elmder Goto Github PK

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    mkElmDerivation.url = github:jeslie0/mkElmDerivation;
  };
  outputs = { self, flake-utils, nixpkgs, mkElmDerivation }:
    flake-utils.lib.eachDefaultSystem
      (system:
        let
          pkgs = import nixpkgs {
            inherit system;
            overlays = [ mkElmDerivation.overlays.mkDotElmDirectoryCmd ];
          };

          elmParcelNixFix = {
            # To make Elm, Parcel and Nix work together we need do some some fixes:
            # 1. The Elm node package tries to download the binary when installing, this doesn't work in Nix's sandbox, so instead we add it to the nativeBuildPackages, set the npmFlag to not run install scripts, and alter this (https://github.com/elm/compiler/blob/047d5026fe6547c842db65f7196fed3f0b4743ee/installers/npm/bin/elm#L8-L30) script to instead of downloading the binary to just use the one we installed as the native build package
            nativeBuildPackages = [ pkgs.elmPackages.elm ];
            npmFlags = [ "--ignore-scripts" ];
            preBuild = ''
            substituteInPlace node_modules/.bin/elm \
            --replace 'var binaryPath = path.resolve' 'var binaryPath = "${pkgs.lib.getExe (pkgs.elmPackages.elm // {meta.mainProgram="elm";})}"; runCommand(); return; //'
            '';
            # 2. Generate the .elm directory 
            generateElmJsonFiles = pkgs.mkDotElmDirectoryCmd ./elm.json;
          };

          buildInputs = with pkgs; [
            elmPackages.elm
            elmPackages.elm-live
            elmPackages.elm-test
            elmPackages.elm-format
            nodejs-18_x
          ];
        in
        {
          packages.default = self.packages.${system}.frontend;
          packages.frontend = pkgs.buildNpmPackage {
            name = "parceljs-with-elm-and-nix";
            src = ./.;

            nativeBuildInputs = elmParcelNixFix.nativeBuildPackages;
            npmFlags = elmParcelNixFix.npmFlags;
            npmPackFlags = [ "--ignore-scripts" ]; # The prepack script runs the build script, which we'd rather do in the build phase.
            prePatch = elmParcelNixFix.generateElmJsonFiles;
            # preConfigure = elmParcelNixFix.generateElmJsonFiles; # seems you can do either prePatch or preConfigure (maybe others? IDK -- I'm new to this)
            preBuild = elmParcelNixFix.preBuild;

            npmDepsHash = "sha256-Lpj6we8KXfdFNEQpWxeLwX0vTPeZRV0B5oRoh9Ur+y4=";
            # npmDepsHash = lib.fakeHash;

            npmBuild = "npm run build";

            installPhase = ''
              mkdir $out
              cp -R dist_prod/* $out/
            '';

          };

          devShells.default = pkgs.mkShell {
            inherit buildInputs;
          };

        }
      );
}