Extract git path logic to its own module

Author: qgadrian

lib/git.ex

@@ -0,0 +1,37 @@
+defmodule GitHooks.Git do
+  @moduledoc false
+
+  alias Mix.Project
+
+  @doc false
+  @spec resolve_git_path() :: any
+  def resolve_git_path do
+    :git_hooks
+    |> Application.get_env(:git_path)
+    |> case do
+      nil ->
+        path = Path.join(Project.deps_path(), "/../.git")
+
+        if File.dir?(path) do
+          path
+        else
+          resolve_git_submodule_path(path)
+        end
+
+      custom_path ->
+        custom_path
+    end
+  end
+
+  @spec resolve_git_submodule_path(String.t()) :: any
+  defp resolve_git_submodule_path(git_path) do
+    with {:ok, contents} <- File.read(git_path),
+         %{"dir" => submodule_dir} <- Regex.named_captures(~r/^gitdir:\s+(?<dir>.*)$/, contents) do
+      Project.deps_path()
+      |> Path.join("/../" <> submodule_dir)
+    else
+      _error ->
+        raise "Error resolving git submodule path '#{git_path}'"
+    end
+  end
+end

lib/mix/tasks/git_hooks/install.ex

@@ -21,8 +21,8 @@ defmodule Mix.Tasks.GitHooks.Install do
   use Mix.Task
 
   alias GitHooks.Config
+  alias GitHooks.Git
   alias GitHooks.Printer
-  alias Mix.Project
 
   @impl true
   @spec run(Keyword.t()) :: :ok
@@ -56,7 +56,7 @@ defmodule Mix.Tasks.GitHooks.Install do
       case File.read(template_file) do
         {:ok, body} ->
           target_file_path =
-            resolve_git_path()
+            Git.resolve_git_path()
             |> Path.join("/hooks/#{git_hook_atom_as_kebab_string}")
 
           target_file_body =
@@ -86,11 +86,11 @@ defmodule Mix.Tasks.GitHooks.Install do
   @spec backup_current_hook(String.t(), Keyword.t()) :: {:error, atom} | {:ok, non_neg_integer()}
   defp backup_current_hook(git_hook_to_backup, opts) do
     source_file_path =
-      resolve_git_path()
+      Git.resolve_git_path()
       |> Path.join("/hooks/#{git_hook_to_backup}")
 
     target_file_path =
-      resolve_git_path()
+      Git.resolve_git_path()
       |> Path.join("/hooks/#{git_hook_to_backup}.pre_git_hooks_backup")
 
     unless opts[:quiet] || !Config.verbose?() do
@@ -104,7 +104,7 @@ defmodule Mix.Tasks.GitHooks.Install do
   defp track_configured_hooks do
     git_hooks = Config.git_hooks() |> Enum.join(" ")
 
-    resolve_git_path()
+    Git.resolve_git_path()
     |> Path.join("/hooks/git_hooks.db")
     |> write_backup(git_hooks)
   end
@@ -121,40 +121,9 @@ defmodule Mix.Tasks.GitHooks.Install do
       )
   end
 
-  @spec resolve_git_path() :: any
-  defp resolve_git_path() do
-    :git_hooks
-    |> Application.get_env(:git_path)
-    |> case do
-      nil ->
-        path = Path.join(Project.deps_path(), "/../.git")
-
-        if File.dir?(path) do
-          path
-        else
-          resolve_git_submodule_path(path)
-        end
-
-      custom_path ->
-        custom_path
-    end
-  end
-
-  @spec resolve_git_submodule_path(String.t()) :: any
-  defp resolve_git_submodule_path(git_path) do
-    with {:ok, contents} <- File.read(git_path),
-         %{"dir" => submodule_dir} <- Regex.named_captures(~r/^gitdir:\s+(?<dir>.*)$/, contents) do
-      Project.deps_path()
-      |> Path.join("/../" <> submodule_dir)
-    else
-      _error ->
-        raise "Error resolving git submodule path '#{git_path}'"
-    end
-  end
-
   @spec ensure_hooks_folder_exists() :: any
   defp ensure_hooks_folder_exists do
-    resolve_git_path()
+    Git.resolve_git_path()
     |> Path.join("/hooks")
     |> File.mkdir_p()
   end
@@ -165,7 +134,7 @@ defmodule Mix.Tasks.GitHooks.Install do
       Config.git_hooks()
       |> Enum.map(&Atom.to_string/1)
 
-    resolve_git_path()
+    Git.resolve_git_path()
     |> Path.join("/git_hooks.db")
     |> File.read()
     |> case do
@@ -180,7 +149,7 @@ defmodule Mix.Tasks.GitHooks.Install do
               "Remove old git hook `#{git_hook_atom_as_kebab_string}` and restore backup"
             )
 
-            resolve_git_path()
+            Git.resolve_git_path()
             |> Path.join("/hooks/#{git_hook_atom_as_kebab_string}")
             |> File.rm()
 
@@ -197,13 +166,13 @@ defmodule Mix.Tasks.GitHooks.Install do
   defp restore_backup(git_hook_atom_as_kebab_string) do
     backup_path =
       Path.join(
-        resolve_git_path(),
+        Git.resolve_git_path(),
         "/hooks/#{git_hook_atom_as_kebab_string}.pre_git_hooks_backup"
       )
 
     restore_path =
       Path.join(
-        resolve_git_path(),
+        Git.resolve_git_path(),
         "/#{git_hook_atom_as_kebab_string}"
       )