Add first tests to install module

test/mix/tasks/git_hooks/install_test.exs

@@ -0,0 +1,44 @@
+defmodule Mix.Tasks.InstallTest do
+  @moduledoc false
+
+  use ExUnit.Case, async: false
+  use GitHooks.TestSupport.ConfigCase
+
+  alias Mix.Tasks.GitHooks.Install
+  alias GitHooks.Git.Path, as: GitPath
+
+  @tag capture_log: true
+
+  describe "run/1" do
+    test "replaces the hook template with config values" do
+      put_git_hook_config(
+        [:pre_commit, :pre_push],
+        tasks: {:cmd, "check"}
+      )
+
+      hooks_file = Install.run(["--dry-run", "--quiet"])
+
+      assert hooks_file == [
+               pre_commit: expect_hook_template("pre_commit"),
+               pre_push: expect_hook_template("pre_push")
+             ]
+    end
+  end
+
+  #
+  # Private functions
+  #
+
+  defp expect_hook_template(git_hook) do
+    app_path = GitPath.resolve_app_path()
+
+    ~s(#!/bin/sh
+
+[ "#{app_path}" != "" ] && cd #{app_path}
+
+mix git_hooks.run #{git_hook} "$@"
+[ $? -ne 0 ] && exit 1
+exit 0
+)
+  end
+end