perform structural deconfuckulation

example/flake.nix

@@ -19,14 +19,11 @@
       systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
 
       perSystem = { config, pkgs, ... }: {
-        deno = {
+        deno-with-packages.lockfiles = [ ./deno.lock ];
-          enable = true;
-          lockfiles = [ ./deno.lock ];
-        };
 
         devShells.default = pkgs.mkShell {
           inputsFrom = [ config.flake-root.devShell ];
-          buildInputs = [ config.packages.deno ];
+          buildInputs = [ config.deno-with-packages.package ];
         };
       };
     };

flake-module.nix

@@ -1,28 +1,16 @@
-{ self, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (flake-parts-lib) mkPerSystemOption;
-  inherit (lib) mkOption mkEnableOption types;
+  inherit (lib) mkOption types;
 in
 {
+  options.perSystem = mkPerSystemOption (
+    { pkgs, config, ... }:
+    let
+      impl = import ./impl.nix { inherit pkgs; };
+      mainSubmodule = types.submodule {
         options = {
-    flake.lib.deno = mkOption {
+          basePackage = mkOption {
-      type = types.attrs;
-      default = {};
-      description = "Deno-related library functions";
-    };
-  };
-
-  options.perSystem = mkPerSystemOption ({ pkgs, system, ... }: {
-    options.deno = {
-      enable = mkEnableOption "Deno with shared cache support";
-      
-      lockfiles = mkOption {
-        type = types.listOf types.path;
-        default = [];
-        description = "List of deno.lock files to build cache from";
-      };
-
-      package = mkOption {
             type = types.package;
             default = pkgs.deno;
             description = "Base deno package to wrap";
@@ -33,156 +21,47 @@ in
             default = "registry.npmjs.org";
             description = "NPM registry hostname";
           };
-    };
-  });
 
-  config = {
+          lockfiles = mkOption {
-    flake.lib.deno = rec {
+            type = types.listOf types.path;
-      denoLockfileToNpmDeps = { pkgs, lockfile, registryHostname }:
+            default = [ ];
-        let
+            description = "List of deno.lock files to build cache from";
-          extractNpmDeps = lockfile:
-            let
-              lockJSON = builtins.fromJSON (builtins.readFile lockfile);
-            in
-              lockJSON.npm or {};
-
-          npmDeps = extractNpmDeps lockfile;
-
-          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://${registryHostname}/${name}/-/${tarballName}-${version}.tgz";
-                hash = integrity;
           };
 
-          mkNpmDep = key: value:
+          dir = mkOption {
-            let
+            type = types.str;
-              match = builtins.match "(@?[^@]+)@([^_]+).*" key;
+            default = "$HOME/.cache/deno-nix";
-              name = builtins.elemAt match 0;
+            description = "What to set DENO_DIR to in the wrapper script";
-              version = builtins.elemAt match 1;
-              cachePath = "npm/${registryHostname}/${name}";
-            in {
-              drv = pkgs.stdenv.mkDerivation {
-                pname = "deno-npm-${builtins.replaceStrings ["@" "/"] ["" "-"] name}";
-                version = version;
-                src = mkTarballDrv {
-                  inherit name version; 
-                  inherit (value) integrity;
           };
 
-                installPhase = ''
+          package = mkOption {
-                  runHook preInstall
+            type = types.package;
-  
+            readOnly = true;
-                  export OUT_PATH="$out/${cachePath}/${version}"
+            description = "Resulting wrapper mimicking Deno executable";
-  
+            default = impl.denoWithCache {
-                  mkdir -p $OUT_PATH
+              baseDeno = config.deno-with-packages.basePackage;
-                  tar -xzf $src -C $OUT_PATH --strip-components=1
+              sharedCache = config.deno-with-packages.cache;
-
+            };
-                  runHook postInstall
+          };
-                '';
+
+          cache = mkOption {
+            type = types.package;
+            readOnly = true;
+            description = "Pre-generated Deno cache based on the given lockfiles";
+            default = impl.denoSharedCache {
+              lockfiles = config.deno-with-packages.lockfiles;
+              registryHostname = config.deno-with-packages.registryHostname;
+            };
+          };
         };
-              inherit name cachePath;
       };
     in
-          pkgs.lib.mapAttrsToList mkNpmDep npmDeps;
-
-      denoSharedCache = { pkgs, lockfiles, registryHostname }:
-        let
-          allNpmDeps = builtins.concatMap
-            (lockfile: denoLockfileToNpmDeps { 
-              inherit pkgs lockfile registryHostname; 
-            })
-            lockfiles;
-          sharedCacheBase = pkgs.symlinkJoin {
-            name = "deno-shared-cache-base";
-            paths = map (d: d.drv) allNpmDeps;
-          };
-        in
-          pkgs.runCommand "deno-shared-cache" {} ''
-            runHook preInstall
-
-            mkdir -p $out
-            chmod -R +w $out
-
-            cp -rs ${sharedCacheBase}/* $out
-
-            while IFS='|' read -r dep name; do
-              chmod +w $out/$dep
-cat > $out/$dep/registry.json <<EOF
     {
-  "name": "$name",
+      options.deno-with-packages = mkOption {
-  "dist-tags": {},
+        type = mainSubmodule;
-  "versions": {}
+        description = "Wrapping Deno with a pre-generated cache";
-}
+        default = { };
-EOF
-              while IFS= read -r ver; do
-                SUBSET_FILTER='to_entries | map(select(.key == "version" or .key == "bin" or .key == "dependencies" or .key == "peerDependencies")) | from_entries'
-                PACKAGE_SUBSET=$(${pkgs.jq}/bin/jq "$SUBSET_FILTER" $out/$dep/$ver/package.json)
-                 ${pkgs.jq}/bin/jq --arg version "$ver" --argjson subset "$PACKAGE_SUBSET" \
-                   '.versions[$version] = $subset' \
-                   $out/$dep/registry.json > $out/$dep/registry.json.tmp
-
-                mv $out/$dep/registry.json.tmp $out/$dep/registry.json
-              done < <(find $out/$dep -mindepth 1 -maxdepth 1 -type d | xargs -n1 basename)
-            done < <(echo "${builtins.concatStringsSep "\n" (map (d: "${d.cachePath}|${d.name}") allNpmDeps)}" | sort -u)
-
-            runHook postInstall
-          '';
-
-      denoWithCache = { pkgs, baseDeno, sharedCache }:
-        pkgs.writeShellScriptBin "deno" ''
-          set -euo pipefail
-
-          if [ -n "''${FLAKE_ROOT:-}" ]; then
-            CACHE_DIR="$FLAKE_ROOT/.deno_cache"
-          else
-            echo "FLAKE_ROOT not set. Make sure you're using the flake-root devShell." >&2
-            exit 1
-          fi
-
-          if [ ! -d "$CACHE_DIR" ] || [ ! "$(ls -A "$CACHE_DIR" 2>/dev/null)" ]; then
-            echo "Setting up Deno cache at: $CACHE_DIR" >&2
-            mkdir -p "$CACHE_DIR"
-            
-            if [ -d "${sharedCache}" ]; then
-              echo "Copying shared cache..." >&2
-              cp -rL "${sharedCache}"/* "$CACHE_DIR"/ 2>/dev/null || true
-              chmod -R u+w "$CACHE_DIR" 2>/dev/null || true
-            fi
-          fi
-      
-          export DENO_DIR="$CACHE_DIR"
-          exec "${baseDeno}/bin/deno" "$@"
-        '';
-    };
-
-    perSystem = { config, pkgs, system, ... }: 
-      lib.mkIf config.deno.enable {
-        packages = lib.mkIf (config.deno.lockfiles != []) {
-          deno = 
-            let
-              sharedCache = self.lib.deno.denoSharedCache {
-                inherit pkgs;
-                lockfiles = config.deno.lockfiles;
-                registryHostname = config.deno.registryHostname;
-              };
-            in
-              self.lib.deno.denoWithCache {
-                inherit pkgs sharedCache;
-                baseDeno = config.deno.package;
-              };
-
-          deno-cache = self.lib.deno.denoSharedCache {
-            inherit pkgs;
-            lockfiles = config.deno.lockfiles;
-            registryHostname = config.deno.registryHostname;
-          };
-        };
-      };
       };
     }
+  );
+}

flake.nix

@@ -1,7 +1,9 @@
 {
   description = "Provides a Deno executable wrapper pointing to pre-built NPM dependency cache based on lock files";
 
-  outputs = { ... }: {
+  outputs =
+    { ... }:
+    {
       flakeModule = ./flake-module.nix;
     };
 }

impl.nix

@@ -0,0 +1,137 @@
+{ pkgs }:
+rec {
+  denoLockfileToNpmDeps =
+    { lockfile, registryHostname }:
+    let
+      extractNpmDeps =
+        lockfile:
+        let
+          lockJSON = builtins.fromJSON (builtins.readFile lockfile);
+        in
+        lockJSON.npm or { };
+
+      npmDeps = extractNpmDeps lockfile;
+
+      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://${registryHostname}/${name}/-/${tarballName}-${version}.tgz";
+          hash = integrity;
+        };
+
+      mkNpmDep =
+        key: value:
+        let
+          match = builtins.match "(@?[^@]+)@([^_]+).*" key;
+          name = builtins.elemAt match 0;
+          version = builtins.elemAt match 1;
+          cachePath = "npm/${registryHostname}/${name}";
+        in
+        {
+          drv = 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/${cachePath}/${version}"
+
+              mkdir -p $OUT_PATH
+              tar -xzf $src -C $OUT_PATH --strip-components=1
+
+              runHook postInstall
+            '';
+          };
+          inherit name cachePath;
+        };
+    in
+    pkgs.lib.mapAttrsToList mkNpmDep npmDeps;
+
+  denoSharedCache =
+    { lockfiles, registryHostname }:
+    let
+      allNpmDeps = builtins.concatMap (
+        lockfile:
+        denoLockfileToNpmDeps {
+          inherit lockfile registryHostname;
+        }
+      ) lockfiles;
+      sharedCacheBase = pkgs.symlinkJoin {
+        name = "deno-shared-cache-base";
+        paths = map (d: d.drv) allNpmDeps;
+      };
+    in
+      pkgs.runCommand "deno-shared-cache" {} ''
+        runHook preInstall
+
+        mkdir -p $out
+        chmod -R +w $out
+
+        cp -rs ${sharedCacheBase}/* $out
+
+        while IFS='|' read -r dep name; do
+          chmod +w $out/$dep
+cat > $out/$dep/registry.json <<EOF
+{
+  "name": "$name",
+  "dist-tags": {},
+  "versions": {}
+}
+EOF
+          while IFS= read -r ver; do
+            SUBSET_FILTER='to_entries | map(select(.key == "version" or .key == "bin" or .key == "dependencies" or .key == "peerDependencies")) | from_entries'
+            PACKAGE_SUBSET=$(${pkgs.jq}/bin/jq "$SUBSET_FILTER" $out/$dep/$ver/package.json)
+             ${pkgs.jq}/bin/jq --arg version "$ver" --argjson subset "$PACKAGE_SUBSET" \
+               '.versions[$version] = $subset' \
+               $out/$dep/registry.json > $out/$dep/registry.json.tmp
+
+            mv $out/$dep/registry.json.tmp $out/$dep/registry.json
+          done < <(find $out/$dep -mindepth 1 -maxdepth 1 -type d | xargs -n1 basename)
+        done < <(echo "${builtins.concatStringsSep "\n" (map (d: "${d.cachePath}|${d.name}") allNpmDeps)}" | sort -u)
+
+        runHook postInstall
+      '';
+
+  denoWithCache =
+    { baseDeno, sharedCache }:
+    pkgs.writeShellScriptBin "deno" ''
+      set -euo pipefail
+
+      if [ -n "''${FLAKE_ROOT:-}" ]; then
+        CACHE_DIR="$FLAKE_ROOT/.deno_cache"
+      else
+        echo "FLAKE_ROOT not set. Make sure you're using the flake-root devShell." >&2
+        exit 1
+      fi
+
+      if [ ! -d "$CACHE_DIR" ] || [ ! "$(ls -A "$CACHE_DIR" 2>/dev/null)" ]; then
+        echo "Setting up Deno cache at: $CACHE_DIR" >&2
+        mkdir -p "$CACHE_DIR"
+
+        if [ -d "${sharedCache}" ]; then
+          echo "Copying shared cache..." >&2
+          cp -rL "${sharedCache}"/* "$CACHE_DIR"/ 2>/dev/null || true
+          chmod -R u+w "$CACHE_DIR" 2>/dev/null || true
+        fi
+      fi
+
+      export DENO_DIR="$CACHE_DIR"
+      exec "${baseDeno}/bin/deno" "$@"
+    '';
+}