yarn-plugin-nixify

WORK IN PROGRESS

Generates a Nix expression to build a Yarn v2 project (not using zero-install).

Usage

yarn plugin import https://raw.githubusercontent.com/stephank/yarn-plugin-nixify/main/dist/yarn-plugin-nixify.js
yarn
nix-build

Running yarn with this plugin enabled will generate two files:

• yarn-project.nix: This file is always overwritten, and contains a basic derivation for your project.

• default.nix: Only generated if it does not exist yet. This file is intended to be customized with any project-specific logic you need.

When building the basic derivation without any customization, it'll run yarn inside your project, copy your project to $out/libexec/<name>, and setup wrappers in $out/bin for any executables declared in the bin field of your top-level package.json.

Some examples of how to customize your build from within default.nix:

{ pkgs ? import <nixpkgs> { } }:

let

  # Example of providing a different source.
  src = fetchFromGitHub {
    owner = "johndoe";
    repo = "myproject";
    rev = "v1.0.0";
    sha256 = "1hdhafj726g45gh7nj8qv1xls8mps3vhzq3aasdymbdqcb1clhkz";
  };

  project = pkgs.callPackage ./yarn-project.nix {

    # Example of selecting a specific version of Node.js.
    nodejs = pkgs.nodejs-14_x;

  } src;

in project.overrideAttrs (oldAttrs: {

  # Example of adding dependencies to the environment.
  # Native modules sometimes need these to build.
  buildInputs = oldAttrs.buildInputs ++ [ python3 ];

  # Example of invoking a build step in your project.
  buildPhase = ''
    yarn build
  '';

})

Hacking

# In this directory:
yarn
yarn build-dev

# In your test project:
yarn plugin import /path/to/yarn-plugin-nixify/dist/yarn-plugin-nixify.dev.js

(Alternatively, add a direct reference in .yarnrc.yml. This will likely only work if the Nix sandbox is disabled.)