Nix builder for Deno projects with npm dependencies. Parses deno.lock at evaluation time to create individual fetchurl derivations per npm package, so no manual hash maintenance is needed.

How it works #

fetchDenoDeps.nix reads deno.lock via builtins.fromJSON, extracts every npm entry, and fetches each tarball with fetchurl using the integrity hash from the lock file.
The fetched tarballs are assembled into a DENO_DIR-compatible cache layout (npm/registry.npmjs.org/<package>/<version>/) with generated registry.json metadata files.
buildDenoProject.nix uses this cache to run deno install --frozen in the Nix sandbox, then executes the provided build command.

Usage #

buildDenoProject is exposed as lib.buildDenoProject in pkgs via the perSystemLib workspace module.

In a workspace package definition:

packages.my-app = { lib, ... }:
  lib.buildDenoProject {
    pname = "my-app";
    src = ./.;
    buildCommand = "deno run -A npm:@rsbuild/core build";
    installPhase = "cp -r dist $out";
  };

Parameters #

Parameter	Default	Description
`src`	required	Source directory containing `deno.lock`
`buildCommand`	required	Shell command to build the project
`installPhase`	required	Shell commands to install build output to `$out`
`pname`	`"deno-project"`	Package name
`version`	`"0.0.0"`	Package version
`lockFile`	`src + "/deno.lock"`	Path to the Deno lock file
`nativeBuildInputs`	`[]`	Additional build inputs
`meta`	`{}`	Nixpkgs meta attributes

Files #

default.nix — workspace module exposing buildDenoProject via perSystemLib
buildDenoProject.nix — Project builder derivation
fetchDenoDeps.nix — npm dependency fetcher using dynamic derivations from deno.lock