flake.nix

{
  description = "A post-modern text editor.";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    nixCargoIntegration = {
      url = "github:yusdacra/nix-cargo-integration";
      inputs.nixpkgs.follows = "nixpkgs";
      inputs.rustOverlay.follows = "rust-overlay";
    };
  };

  outputs = inputs @ {
    nixpkgs,
    nixCargoIntegration,
    ...
  }:
    nixCargoIntegration.lib.makeOutputs {
      root = ./.;
      renameOutputs = {"helix-term" = "helix";};
      # Set default app to hx (binary is from helix-term release build)
      # Set default package to helix-term release build
      defaultOutputs = {
        app = "hx";
        package = "helix";
      };
      overrides = {
        cCompiler = common:
          with common.pkgs;
            if stdenv.isLinux
            then gcc
            else clang;
        crateOverrides = common: _: {
          helix-term = prev: let
            inherit (common) pkgs;
            mkRootPath = rel:
              builtins.path {
                path = "${common.root}/${rel}";
                name = rel;
              };
            grammars = pkgs.callPackage ./grammars.nix {};
            runtimeDir = pkgs.runCommandNoCC "helix-runtime" {} ''
              mkdir -p $out
              ln -s ${mkRootPath "runtime"}/* $out
              rm -r $out/grammars
              ln -s ${grammars} $out/grammars
            '';
          in {
            # disable fetching and building of tree-sitter grammars in the helix-term build.rs
            HELIX_DISABLE_AUTO_GRAMMAR_BUILD = "1";
            # link languages and theme toml files since helix-term expects them (for tests)
            preConfigure =
              pkgs.lib.concatMapStringsSep
              "\n"
              (path: "ln -sf ${mkRootPath path} ..")
              ["languages.toml" "theme.toml" "base16_theme.toml"];
            buildInputs = (prev.buildInputs or []) ++ [common.cCompiler.cc.lib];
            nativeBuildInputs = [pkgs.makeWrapper];

            postFixup = ''
              if [ -f "$out/bin/hx" ]; then
                wrapProgram "$out/bin/hx" --set HELIX_RUNTIME "${runtimeDir}"
              fi
            '';
          };
        };
        shell = common: prev: {
          packages =
            prev.packages
            ++ (
              with common.pkgs; [lld_13 lldb cargo-tarpaulin cargo-flamegraph]
            );
          env =
            prev.env
            ++ [
              {
                name = "HELIX_RUNTIME";
                eval = "$PWD/runtime";
              }
              {
                name = "RUST_BACKTRACE";
                value = "1";
              }
              {
                name = "RUSTFLAGS";
                value =
                  if common.pkgs.stdenv.isLinux
                  then "-C link-arg=-fuse-ld=lld -C target-cpu=native -Clink-arg=-Wl,--no-rosegment"
                  else "";
              }
            ];
        };
      };
    };
}