Ensure only directories exist in Rails default load paths

Previously, some files put under `app` directory would contaminate the load paths.
This commit removes files from the default load paths set up by the Rails framework.

Now, only directories are included as default in the following paths:

* autoload_paths
* autoload_once_paths
* eager_load_paths
* load_paths

railties/CHANGELOG.md

@@ -1,3 +1,17 @@
+*   Ensure only directories exist in Rails default load paths
+
+    Previously, some files put under `app` directory would contaminate the load paths.
+    This commit removes files from the default load paths set up by the Rails framework.
+
+    Now, only directories are included as default in the following paths:
+
+    * autoload_paths
+    * autoload_once_paths
+    * eager_load_paths
+    * load_paths
+
+    *Takumasa Ochi*
+
 *   Prevent unnecessary application reloads in development.
 
     Previously, some files outside autoload paths triggered unnecessary reloads.

railties/lib/rails/paths.rb

@@ -105,8 +105,8 @@ module Rails
     private
       def filter_by(&block)
         all_paths.find_all(&block).flat_map { |path|
-          paths = path.existent
-          paths - path.children.flat_map { |p| yield(p) ? [] : p.existent }
+          paths = path.existent_directories
+          paths - path.children.flat_map { |p| yield(p) ? [] : p.existent_directories }
         }.uniq
       end
     end

railties/test/paths_test.rb

@@ -101,7 +101,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to add a path that should be autoloaded only once" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app"
       @root["app"].autoload_once!
       assert_predicate @root["app"], :autoload_once?
@@ -120,7 +120,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to add a path without assignment and specify it should be loaded only once" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app", autoload_once: true
       assert_predicate @root["app"], :autoload_once?
       assert_includes @root.autoload_once, "/app"
@@ -128,7 +128,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to add multiple paths without assignment and specify it should be loaded only once" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: ["/app", "/app2"], autoload_once: true
       assert_predicate @root["app"], :autoload_once?
       assert_includes @root.autoload_once, "/app"
@@ -137,7 +137,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "making a path autoload_once more than once only includes it once in @root.load_once" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "/app"
       @root["app"].autoload_once!
       @root["app"].autoload_once!
@@ -146,7 +146,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "paths added to a load_once path should be added to the autoload_once collection" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "/app"
       @root["app"].autoload_once!
       @root["app"] << "/app2"
@@ -155,7 +155,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to mark a path as eager loaded" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "/app"
       @root["app"].eager_load!
       assert_predicate @root["app"], :eager_load?
@@ -174,7 +174,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to add a path without assignment and mark it as eager" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app", eager_load: true
       assert_predicate @root["app"], :eager_load?
       assert_includes @root.eager_load, "/app"
@@ -182,7 +182,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to add multiple paths without assignment and mark them as eager" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: ["/app", "/app2"], eager_load: true
       assert_predicate @root["app"], :eager_load?
       assert_includes @root.eager_load, "/app"
@@ -191,7 +191,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "it is possible to create a path without assignment and mark it both as eager and load once" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app", eager_load: true, autoload_once: true
       assert_predicate @root["app"], :eager_load?
       assert_predicate @root["app"], :autoload_once?
@@ -201,7 +201,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "making a path eager more than once only includes it once in @root.eager_paths" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "/app"
       @root["app"].eager_load!
       @root["app"].eager_load!
@@ -210,7 +210,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "paths added to an eager_load path should be added to the eager_load collection" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "/app"
       @root["app"].eager_load!
       @root["app"] << "/app2"
@@ -243,7 +243,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "a path can be added to the load path" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "app"
       @root["app"].load_path!
       @root["app/models"] = "app/models"
@@ -252,7 +252,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "a path can be added to the load path on creation" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app", load_path: true
       assert_predicate @root["app"], :load_path?
       assert_equal ["/app"], @root.load_paths
@@ -260,7 +260,7 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "a path can be marked as autoload path" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root["app"] = "app"
       @root["app"].autoload!
       @root["app/models"] = "app/models"
@@ -269,12 +269,32 @@ class PathsTest < ActiveSupport::TestCase
   end
 
   test "a path can be marked as autoload on creation" do
-    File.stub(:exist?, true) do
+    File.stub(:directory?, true) do
       @root.add "app", with: "/app", autoload: true
       assert_predicate @root["app"], :autoload?
       assert_equal ["/app"], @root.autoload_paths
     end
   end
+
+  test "load paths does NOT include files" do
+    File.stub(:directory?, false) do
+      @root.add "app/README.md", autoload_once: true, eager_load: true, autoload: true, load_path: true
+      assert_equal [], @root.autoload_once
+      assert_equal [], @root.eager_load
+      assert_equal [], @root.autoload_paths
+      assert_equal [], @root.load_paths
+    end
+  end
+
+  test "load paths does include directories" do
+    File.stub(:directory?, true) do
+      @root.add "app/special", autoload_once: true, eager_load: true, autoload: true, load_path: true
+      assert_equal ["/foo/bar/app/special"], @root.autoload_once
+      assert_equal ["/foo/bar/app/special"], @root.eager_load
+      assert_equal ["/foo/bar/app/special"], @root.autoload_paths
+      assert_equal ["/foo/bar/app/special"], @root.load_paths
+    end
+  end
 end
 
 class PathsIntegrationTest < ActiveSupport::TestCase