Merge pull request #14684 from Futurelearn/jc-deep-nested-shallow-url-helper-bug

Add a failing test for a URL helper that was broken by a6b9ea2e.

actionpack/CHANGELOG.md

+*   Only make deeply nested routes shallow when parent is shallow.
+
+    Fixes #14684.
+
+    *Andrew White*, *James Coglan*
+
 *   Append link to bad code to backtrace when exception is SyntaxError.
 
     *Boris Kuznetsov*
-    
+
 *   Swapped the parameters of assert_equal in `assert_select` so that the
-    proper values were printed correctly 
+    proper values were printed correctly
 
     Fixes #14422.
 

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -995,6 +995,7 @@ def initialize(entities, options = {})
             @as         = options[:as]
             @param      = (options[:param] || :id).to_sym
             @options    = options
+            @shallow    = false
           end
 
           def default_actions
@@ -1055,6 +1056,13 @@ def nested_scope
             "#{path}/:#{nested_param}"
           end
 
+          def shallow=(value)
+            @shallow = value
+          end
+
+          def shallow?
+            @shallow
+          end
         end
 
         class SingletonResource < Resource #:nodoc:
@@ -1361,7 +1369,7 @@ def nested
           end
 
           with_scope_level(:nested) do
-            if shallow? && nesting_depth > 1
+            if shallow? && shallow_nesting_depth > 1
               shallow_scope(parent_resource.nested_scope, nested_options) { yield }
             else
               scope(parent_resource.nested_scope, nested_options) { yield }
@@ -1576,6 +1584,7 @@ def with_scope_level(kind)
           end
 
           def resource_scope(kind, resource) #:nodoc:
+            resource.shallow = @scope[:shallow]
             old_resource, @scope[:scope_level_resource] = @scope[:scope_level_resource], resource
             @nesting.push(resource)
 
@@ -1600,6 +1609,10 @@ def nesting_depth #:nodoc:
             @nesting.size
           end
 
+          def shallow_nesting_depth #:nodoc:
+            @nesting.select(&:shallow?).size
+          end
+
           def param_constraint? #:nodoc:
             @scope[:constraints] && @scope[:constraints][parent_resource.param].is_a?(Regexp)
           end

actionpack/test/dispatch/routing_test.rb

@@ -1994,6 +1994,24 @@ def test_shallow_nested_resources_inside_resource
     assert_equal 'cards#destroy', @response.body
   end
 
+  def test_shallow_deeply_nested_resources
+    draw do
+      resources :blogs do
+        resources :posts do
+          resources :comments, shallow: true
+        end
+      end
+    end
+
+    get '/comments/1'
+    assert_equal 'comments#show', @response.body
+
+    assert_equal '/comments/1', comment_path('1')
+    assert_equal '/blogs/new', new_blog_path
+    assert_equal '/blogs/1/posts/new', new_blog_post_path(:blog_id => 1)
+    assert_equal '/blogs/1/posts/2/comments/new', new_blog_post_comment_path(:blog_id => 1, :post_id => 2)
+  end
+
   def test_shallow_nested_resources_within_scope
     draw do
       scope '/hello' do