writers: init

flake-parts/writers/default.nix

@@ -0,0 +1,45 @@
+{ flake-parts-lib, ... }: {
+  options.perSystem = flake-parts-lib.mkPerSystemOption (
+    { config
+    , lib
+    , pkgs
+    , ...
+    }:
+    let
+      writers = pkgs.callPackage ./writers.nix { };
+    in
+    {
+      options.writers = {
+        writePureShellScript = lib.mkOption {
+          type = lib.types.functionTo (lib.types.functionTo lib.types.package);
+          description = ''
+            Create a script that runs in a `pure` environment, in the sense that:
+              - the behavior is similar to `nix-shell --pure`
+              - `PATH` only contains exactly the packages passed via the `PATH` arg
+              - `NIX_PATH` is set to the path of the current `pkgs`
+              - `TMPDIR` is set up and cleaned up even if the script fails
+              - out, if set, is kept as-is
+              - all environment variables are unset, except:
+                - the ones listed in `keepVars` defined in ./default.nix
+                - the ones listed via the `KEEP_VARS` variable
+          '';
+        };
+        writePureShellScriptBin = lib.mkOption {
+          type = lib.types.functionTo (lib.types.functionTo (lib.types.functionTo lib.types.package));
+          description = ''
+            Creates a script in a `bin/` directory in the output; suitable for use with `lib.makeBinPath`, etc.
+            See {option}`writers.writePureShellScript`
+          '';
+        };
+      };
+
+      config.writers = {
+        inherit
+          (writers)
+          writePureShellScript
+          writePureShellScriptBin
+          ;
+      };
+    }
+  );
+}