Ensure git path resolution for different versions

Updated `resolve_git_path/1` to handle both legacy and modern
git versions correctly and ensured absolute paths are
returned for all git-related path resolution functions.

Author: qgadrian

lib/git/git_path.ex

@@ -1,35 +1,69 @@
 defmodule GitHooks.Git.GitPath do
   @moduledoc false
 
+  alias GitHooks.Git
+
   @doc """
   Returns the absolute path to the project's root directory.
   """
   def resolve_app_path do
-    # Attempt to get the project path from the config,
-    # otherwise find the git root by traversing upwards.
-    Application.get_env(:git_hooks, :project_path) ||
+    project_path = Application.get_env(:git_hooks, :project_path)
+
+    if project_path do
+      Path.expand(project_path)
+    else
+      # Find the git root by traversing upwards
       find_git_root(File.cwd!()) ||
-      raise "Could not find .git directory from #{File.cwd!()}"
+        raise "Could not find .git directory from #{File.cwd!()}"
+    end
   end
 
   @doc """
   Returns the absolute `.git/hooks` path directory for the parent project.
   """
   def resolve_git_hooks_path do
-    Path.join(resolve_git_dir(), "hooks")
+    "hooks"
+    |> resolve_git_path()
+    |> Path.expand(resolve_app_path())
   end
 
   @doc """
   Returns the path to a specific hook file within the `.git/hooks` directory.
   """
   def git_hooks_path_for(hook_name) do
-    Path.join(resolve_git_hooks_path(), hook_name)
+    resolve_git_hooks_path()
+    |> Path.join(hook_name)
+    |> Path.expand()
   end
 
   #
   # Private helper functions
   #
 
+  # Resolves the absolute path to a directory within the `.git` directory
+  defp resolve_git_path(dir) when is_binary(dir) and dir != "" do
+    git_path =
+      Git.git_version()
+      |> Version.compare(Version.parse!("2.10.0"))
+      |> case do
+        :lt ->
+          git_dir = resolve_git_dir()
+          Path.join(git_dir, dir)
+
+        _ ->
+          {git_path, 0} =
+            System.cmd("git", ["rev-parse", "--git-path", dir], cd: resolve_app_path())
+
+          String.trim(git_path)
+      end
+
+    Path.expand(git_path, resolve_app_path())
+  end
+
+  defp resolve_git_path(_dir) do
+    raise ArgumentError, "resolve_git_path/1 requires a non-empty directory argument"
+  end
+
   # Returns the absolute `.git` directory path for the parent project.
   defp resolve_git_dir do
     {git_dir, 0} =

mix.exs

@@ -4,7 +4,7 @@ defmodule GitHooks.MixProject do
   use Mix.Project
 
   @source_url "https://github.com/qgadrian/elixir_git_hooks"
-  @version "0.8.0-pre1"
+  @version "0.8.0-pre2"
 
   def project do
     [