From 04d16d93f86432e28faeb492445fc16f240553b7 Mon Sep 17 00:00:00 2001
From: Christian Koch <ckoch@cars.com>
Date: Wed, 20 Jul 2022 11:57:36 -0500
Subject: [PATCH] fix(ExFactor.Extractor): create path! for new modules

Ensure we attempt create a new path as needed and raise exceptions on File failures.
---
 lib/ex_factor/extractor.ex        |  6 +++-
 test/ex_factor/extractor_test.exs | 54 ++++++++++++++++++++++++-------
 test/ex_factor_test.exs           | 10 ++++++
 3 files changed, 57 insertions(+), 13 deletions(-)

diff --git a/lib/ex_factor/extractor.ex b/lib/ex_factor/extractor.ex
index 0a44cfd..431a745 100644
--- a/lib/ex_factor/extractor.ex
+++ b/lib/ex_factor/extractor.ex
@@ -83,7 +83,11 @@ defmodule ExFactor.Extractor do
   end
 
   defp write_file(target_path, contents, module, _dry_run) do
-    _ = File.write(target_path, contents, [:write])
+    target_path
+    |> Path.dirname()
+    |> File.mkdir_p!()
+
+    File.write!(target_path, contents, [:write])
 
     %{
       module: module,
diff --git a/test/ex_factor/extractor_test.exs b/test/ex_factor/extractor_test.exs
index cef8557..c6b4b39 100644
--- a/test/ex_factor/extractor_test.exs
+++ b/test/ex_factor/extractor_test.exs
@@ -2,20 +2,16 @@ defmodule ExFactor.ExtractorTest do
   use ExUnit.Case
   alias ExFactor.Extractor
 
-  setup_all do
+  setup do
     File.mkdir_p("test/tmp")
+    File.mkdir_p("lib/ex_factor/tmp")
 
     on_exit(fn ->
+      File.rm_rf("lib/ex_factor/tmp")
       File.rm_rf("test/tmp")
     end)
   end
 
-  setup do
-    File.rm_rf("lib/ex_factor/tmp")
-    File.mkdir_p("lib/ex_factor/tmp")
-    :ok
-  end
-
   describe "emplace/1" do
     test "requires some options" do
       opts = [
@@ -32,6 +28,45 @@ defmodule ExFactor.ExtractorTest do
     test "noop when no matching fns found in source" do
     end
 
+    test "create the dir path if necessary" do
+      content = """
+      defmodule ExFactorSampleModule do
+        @somedoc "This is somedoc"
+        # a comment and no aliases
+        _docp = "here's an arbitrary module underscore"
+        @spec pub1(term()) :: term()
+        def pub1(arg1) do
+          :pub1_ok
+        end
+      end
+      """
+
+      File.write("test/tmp/source_module.ex", content)
+
+      opts = [
+        target_module: "ExFactor.Test.NewModule",
+        source_module: "ExFactorSampleModule",
+        source_path: "test/tmp/source_module.ex",
+        source_function: :pub1,
+        arity: 1
+      ]
+
+      Extractor.emplace(opts)
+      file = File.read!("lib/ex_factor/test/new_module.ex")
+
+      assert file =~ "def pub1(arg1) do"
+      assert file =~ "defmodule ExFactor.Test.NewModule do"
+      # includes additional attrs
+      assert file =~ "@spec pub1(term()) :: term()"
+      assert file =~ "@somedoc \"This is somedoc\""
+      # assert the added elements get flattened correctly
+      refute file =~ "[@somedoc \"This is somedoc\", "
+      # comments don't get moved
+      refute file =~ "# a comment and no aliases"
+
+      File.rm_rf("lib/ex_factor/test")
+    end
+
     test "write a new file with the function" do
       content = """
       defmodule ExFactorSampleModule do
@@ -48,7 +83,6 @@ defmodule ExFactor.ExtractorTest do
       File.write("test/tmp/source_module.ex", content)
 
       target_path = "test/tmp/target_module.ex"
-      File.rm(target_path)
 
       opts = [
         target_path: target_path,
@@ -71,8 +105,6 @@ defmodule ExFactor.ExtractorTest do
       refute file =~ "[@somedoc \"This is somedoc\", "
       # comments don't get moved
       refute file =~ "# a comment and no aliases"
-      File.rm("test/tmp/source_module.ex")
-      File.rm("test/tmp/target_module.ex")
     end
 
     test "write a new file add a moduledoc comment" do
@@ -88,7 +120,6 @@ defmodule ExFactor.ExtractorTest do
       File.write("test/tmp/source_module.ex", content)
 
       target_path = "test/tmp/target_module.ex"
-      File.rm(target_path)
 
       opts = [
         target_path: target_path,
@@ -122,7 +153,6 @@ defmodule ExFactor.ExtractorTest do
       File.write("test/tmp/source_module.ex", content)
 
       target_path = "test/tmp/target_module.ex"
-      File.rm(target_path)
 
       opts = [
         target_path: target_path,
diff --git a/test/ex_factor_test.exs b/test/ex_factor_test.exs
index e14bb55..2efe8ec 100644
--- a/test/ex_factor_test.exs
+++ b/test/ex_factor_test.exs
@@ -9,6 +9,16 @@ defmodule ExFactorTest do
     end)
   end
 
+  describe "path/1" do
+    test "convert a module name to a file path" do
+      assert "lib/test_module.ex" == ExFactor.path(TestModule)
+    end
+
+    test "convert a multi-atom module name to a file path" do
+      assert "lib/my/test/module_name.ex" == ExFactor.path(My.Test.ModuleName)
+    end
+  end
+
   describe "refactor/1" do
     test "it refactors the functions into a new module, specified in opts" do
       File.rm("lib/ex_factor/tmp/source_module.ex")