initial commit

.gitignore

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+.emacs*
+.deno_cache

README.md

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+# Deno with packages
+
+This flake provides utilities for managing Deno dependencies with Nix,
+- reading multiple lock files
+- creating a derivation per Deno dependency
+- combining those into a single derivation
+- installing shared cache into `DENO_DIR`
+
+Currently only NPM dependencies are recognized.
+
+## Usage
+
+See `flake.nix`

deno.lock

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+{
+  "version": "5",
+  "specifiers": {
+    "npm:@types/node@*": "22.13.4",
+    "npm:hjson@^3.2.2": "3.2.2",
+    "npm:jq-web@~0.6.2": "0.6.2"
+  },
+  "npm": {
+    "@types/node@22.13.4": {
+      "integrity": "sha512-ywP2X0DYtX3y08eFVx5fNIw7/uIv8hYUKgXoK8oayJlLnKcRfEYCxWMVE1XagUdVtCJlZT1AU4LXEABW+L1Peg==",
+      "dependencies": [
+        "undici-types"
+      ]
+    },
+    "hjson@3.2.2": {
+      "integrity": "sha512-MkUeB0cTIlppeSsndgESkfFD21T2nXPRaBStLtf3cAYA2bVEFdXlodZB0TukwZiobPD1Ksax5DK4RTZeaXCI3Q==",
+      "bin": true
+    },
+    "jq-web@0.6.2": {
+      "integrity": "sha512-+7XvjBYwTx4vP5PYkf6Q6orubO/v+UgMU6By1GritrmShr9QpT3UKa4ANzXWQfhdqtBnQYXsm7ZNbdIHT6tYpQ=="
+    },
+    "undici-types@6.20.0": {
+      "integrity": "sha512-Ny6QZ2Nju20vw1SRHe3d9jVu6gJ+4e3+MMpqu7pqE5HT6WsTSlce++GQmK5UXS8mzV8DSYHrQH+Xrf2jVcuKNg=="
+    }
+  },
+  "workspace": {
+    "dependencies": [
+      "npm:hjson@^3.2.2",
+      "npm:jq-web@~0.6.2"
+    ]
+  }
+}

flake.lock

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+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1754214453,
+        "narHash": "sha256-Q/I2xJn/j1wpkGhWkQnm20nShYnG7TI99foDBpXm1SY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "5b09dc45f24cf32316283e62aec81ffee3c3e376",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

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+{
+  description = "Builds a shared cache for Deno packages based on lock files";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in rec
+      {
+        lib = {
+          # Extract NPM dependencies from a single Deno lock file
+          denoLockfileToNpmDeps = import ./lib/lockfile-to-npm-deps.nix { self = lib; };
+
+          # Create a shared Deno cache from multiple lock files
+          denoSharedCache = import ./lib/shared-cache.nix { self = lib; };
+
+          # Install shared cache into DENO_DIR
+          installDenoCache = import ./lib/install-cache.nix;
+
+          denoNpmRegistryHostname = "registry.npmjs.org";
+        };
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            deno
+          ];
+
+          shellHook = 
+            let
+              # Example
+              sharedCache = self.lib.${system}.denoSharedCache {
+                inherit pkgs;
+                lockfiles = [ ./deno.lock ]; # Add your lock files here
+              };
+              installScript = self.lib.${system}.installDenoCache {
+                inherit pkgs;
+                cache = sharedCache;
+              };
+            in
+            ''
+              export DENO_DIR="$PWD/.deno_cache"
+
+              if [ -d "${sharedCache}" ]; then
+                echo "Installing Deno shared cache..."
+                ${installScript}/bin/install-deno-cache
+              fi
+
+              echo "Deno development environment ready!"
+              echo "DENO_DIR is set to: $DENO_DIR"
+            '';
+        };
+      }
+    );
+}

lib/install-cache.nix

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+{ pkgs, cache }:
+
+pkgs.writeShellScriptBin "install-deno-cache" ''
+  set -euo pipefail
+
+  if [ -z "''${DENO_DIR:-}" ]; then
+    echo "Error: DENO_DIR environment variable must be set" >&2
+    exit 1
+  fi
+
+  echo "Installing Deno cache to: $DENO_DIR"
+
+  # Remove existing cache if it exists
+  if [ -d "$DENO_DIR" ]; then
+    echo "Removing existing cache..."
+    rm -rf "$DENO_DIR"
+  fi
+
+  # Copy the shared cache, dereferencing symlinks
+  if [ -d "${cache}" ]; then
+    echo "Copying shared cache..."
+    mkdir -p "$(dirname "$DENO_DIR")"
+    cp -rL "${cache}" "$DENO_DIR"
+    chmod -R u+w "$DENO_DIR"
+    echo "Cache installed successfully!"
+  else
+    echo "No shared cache found at ${cache}"
+    mkdir -p "$DENO_DIR"
+  fi
+
+  if [ -d "$DENO_DIR/npm" ]; then
+    echo "NPM packages in cache: $(find "$DENO_DIR/npm" -name "package.json" | wc -l)"
+  fi
+''

lib/lockfile-to-npm-deps.nix

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+{ self }:
+{ pkgs, lockfile }:
+let
+  registry = self.denoNpmRegistryHostname;
+
+  # Extract npm dependencies from a single lockfile
+  extractNpmDeps = lockfile:
+    let
+      lockJSON = builtins.fromJSON (builtins.readFile lockfile);
+    in
+      lockJSON.npm or {};
+
+  npmDeps = extractNpmDeps lockfile;
+
+  # Create tarball derivation for a package
+  mkTarballDrv = { name, version, integrity }:
+    let
+      tarballName =
+        if builtins.substring 0 1 name == "@" 
+        then builtins.baseNameOf name  # "@types/node" → "node"
+        else name;
+    in
+      pkgs.fetchurl {
+        url = "https://${registry}/${name}/-/${tarballName}-${version}.tgz";
+        hash = integrity;
+      };
+
+  # Create derivation for a single npm package
+  mkNpmDep = key: value:
+    let
+      match = builtins.match "(.+)@(.+)" key;
+      name = builtins.elemAt match 0;
+      version = builtins.elemAt match 1;
+    in
+    pkgs.stdenv.mkDerivation {
+      pname = "deno-npm-${builtins.replaceStrings ["@" "/"] ["" "-"] name}";
+      version = version;
+      src = mkTarballDrv {
+        inherit name version; 
+        inherit (value) integrity;
+      };
+
+      installPhase = ''
+        runHook preInstall
+
+        export OUT_PATH="$out/npm/${registry}/${name}/${version}"
+
+        mkdir -p $OUT_PATH
+        tar -xzf $src -C $OUT_PATH --strip-components=1
+
+        runHook postInstall
+      '';
+    };
+
+in
+pkgs.lib.mapAttrsToList mkNpmDep npmDeps

lib/shared-cache.nix

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+{ self }:
+{ pkgs, lockfiles }:
+let
+  allNpmDeps = builtins.concatMap
+    (lockfile:
+      self.denoLockfileToNpmDeps { inherit pkgs lockfile; })
+    lockfiles;
+
+in
+pkgs.symlinkJoin {
+  name = "deno-shared-cache";
+  paths = allNpmDeps;
+}