flake: add custom lib with initial perl application builder

Signed-off-by: Christoph Heiss <christoph@c8h4.io>

flake.nix

@@ -67,7 +67,10 @@
     , sops-nix, lix-module, ... }:
     flake-utils.lib.eachSystem [ "x86_64-linux" "aarch64-linux" ] (system:
       let
-        pkgs = import nixpkgs { inherit system; };
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ (import ./lib) ];
+        };
         inherit (pkgs) lib;
         inherit (flake-utils.lib) mkApp;
 
@@ -145,6 +148,7 @@
         packages = (import ./pkgs) null pkgs;
       }) // (let
         overlays = [
+          (nixpkgs.lib.composeManyExtensions [ (import ./lib) ])
           (import ./pkgs)
           (self: super: {
             vimPlugins = super.vimPlugins

lib/default.nix

@@ -0,0 +1,31 @@
+_:
+{ lib, writeTextFile, perl, perlPackages, ... }:
+
+{
+  c8h4.buildPerlApplication = { name, text, perlInputs ? (_: [ ])
+    , runtimeInputs ? [ ], derivationArgs ? { } }:
+    writeTextFile {
+      inherit name derivationArgs;
+      executable = true;
+      destination = "/bin/${name}";
+
+      checkPhase = ''
+        runHook preCheck
+        ${lib.getExe perlPackages.PerlCritic} $target
+        runHook postCheck
+      '';
+
+      text = ''
+        #!${lib.getExe (perl.withPackages perlInputs)}
+
+        use strict;
+        use warnings;
+
+        $ENV{PATH} = "${lib.makeBinPath runtimeInputs}:$ENV{PATH}";
+
+        ${text}
+      '';
+
+      meta.mainProgram = name;
+    };
+}