From 45633dc6a0512cbbb010bc615b5d1b6e46e57597 Mon Sep 17 00:00:00 2001
From: Tom Hubrecht <tom.hubrecht@dgnum.eu>
Date: Wed, 22 Jan 2025 13:09:37 +0100
Subject: [PATCH] feat(nix-reuse): Add installPath option

This allows installing the REUSE.toml file in a distinct directory from
the git toplevel
---
 modules/reuse.nix | 54 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 19 deletions(-)

diff --git a/modules/reuse.nix b/modules/reuse.nix
index b9e8729..7a9bbf0 100644
--- a/modules/reuse.nix
+++ b/modules/reuse.nix
@@ -64,6 +64,14 @@ in
       readOnly = true;
     };
 
+    installPath = mkOption {
+      type = nullOr str;
+      default = null;
+      description = ''
+        Where to place the REUSE.toml generated file, if `null`, the file will be placed in the git toplevel directory.
+      '';
+    };
+
     defaultLicense = mkOption {
       type = nullOr str;
       default = null;
@@ -188,25 +196,33 @@ in
       }
     ];
 
-    installationScript =
-      # bash
-      ''
-        if ! type -t git >/dev/null; then
-          # This happens in pure shells, including lorri
-          echo 1>&2 "WARNING: nix-reuse: git command not found; skipping installation."
-        elif ! git rev-parse --git-dir &> /dev/null; then
-          echo 1>&2 "WARNING: nix-reuse: .git not found; skipping installation."
+    installationScript = builtins.concatStringsSep "\n" [
+      (
+        if cfg.installPath == null then
+          ''
+            if ! type -t git >/dev/null; then
+              # This happens in pure shells, including lorri
+              echo 1>&2 "WARNING: nix-reuse: git command not found; skipping installation."
+            elif ! git rev-parse --git-dir &> /dev/null; then
+              echo 1>&2 "WARNING: nix-reuse: .git not found; skipping installation."
+            else
+              GIT_WC=`git rev-parse --show-toplevel`
+
+              # Install REUSE.toml
+              if [ ! -f "$GIT_WC/REUSE.toml" ] || ! ${getExe' pkgs.diffutils "cmp"} -s "$GIT_WC/REUSE.toml" ${result} ; then
+                # Copy the updated workflow definition
+                cp --no-preserve=mode,ownership ${result} "$GIT_WC/REUSE.toml" && echo "nix-reuse: Updated REUSE.toml"
+              fi
+            fi
+          ''
         else
-          GIT_WC=`git rev-parse --show-toplevel`
-
-          # Install REUSE.toml
-          if [ ! -f "$GIT_WC/REUSE.toml" ] || ! ${getExe' pkgs.diffutils "cmp"} -s "$GIT_WC/REUSE.toml" ${result} ; then
-            # Copy the updated workflow definition
-            cp --no-preserve=mode,ownership ${result} "$GIT_WC/REUSE.toml" && echo "nix-reuse: Updated REUSE.toml"
-          fi
-        fi
-
-        ${optionalString config.downloadLicenses "${getExe pkgs.reuse} download --all"}
-      '';
+          ''
+            if [ ! -f "${cfg.installPath}/REUSE.toml" ] || ! ${getExe' pkgs.diffutils "cmp"} -s "${cfg.installPath}/REUSE.toml" ${result} ; then
+              cp --no-preserve=mode,ownership ${result} "${cfg.installPath}/REUSE.toml" && echo "nix-reuse: Updated REUSE.toml"
+            fi
+          ''
+      )
+      (optionalString config.downloadLicenses "${getExe pkgs.reuse} download --all")
+    ];
   };
 }