Merge pull request #20574 from repinel/fix-db-fixtures-load

Allow fixtures YAML files to set the model class in the file itself

Conflicts:
	activerecord/CHANGELOG.md

8 files changed, 130 insertions, 14 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 6c0722e43c..50a556daff 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,16 @@
+*   Allow fixtures files to set the model class in the YAML file itself.
+
+    To load the fixtures file `accounts.yml` as the `User` model, use:
+
+          _fixture:
+            model_class: User
+          david:
+            name: David
+
+    Fixes #9516.
+
+    *Roque Pinel*
+
 *   Don't require a database connection to load a class which uses acceptance
     validations.
 
diff --git a/activerecord/lib/active_record/fixture_set/file.rb b/activerecord/lib/active_record/fixture_set/file.rb
index 8132310c91..f969556c50 100644
--- a/activerecord/lib/active_record/fixture_set/file.rb
+++ b/activerecord/lib/active_record/fixture_set/file.rb
@@ -17,24 +17,39 @@ module ActiveRecord
 
       def initialize(file)
         @file = file
-        @rows = nil
       end
 
       def each(&block)
         rows.each(&block)
       end
 
+      def model_class
+        config_row['model_class']
+      end
 
       private
         def rows
-          return @rows if @rows
+          @rows ||= raw_rows.reject { |fixture_name, _| fixture_name == '_fixture' }
+        end
+
+        def config_row
+          @config_row ||= begin
+            row = raw_rows.find { |fixture_name, _| fixture_name == '_fixture' }
+            if row
+              row.last
+            else
+              {'model_class': nil}
+            end
+          end
+        end
 
-          begin
+        def raw_rows
+          @raw_rows ||= begin
             data = YAML.load(render(IO.read(@file)))
+            data ? validate(data).to_a : []
           rescue ArgumentError, Psych::SyntaxError => error
             raise Fixture::FormatError, "a YAML error occurred parsing #{@file}. Please note that YAML must be consistently indented using spaces. Tabs are not allowed. Please have a look at http://www.yaml.org/faq.html\nThe exact error was:\n  #{error.class}: #{error}", error.backtrace
           end
-          @rows = data ? validate(data).to_a : []
         end
 
         def render(content)
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index f1dc56df63..59df3c78f3 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -395,6 +395,20 @@ module ActiveRecord
   #     <<: *DEFAULTS
   #
   # Any fixture labeled "DEFAULTS" is safely ignored.
+  #
+  # == Configure the fixture model class
+  #
+  # It's possible to set the fixture's model class directly in the YAML file.
+  # This is helpful when fixtures are loaded outside tests and
+  # +set_fixture_class+ is not available (e.g.
+  # when running <tt>rake db:fixtures:load</tt>).
+  #
+  #   _fixture:
+  #     model_class: User
+  #   david:
+  #     name: David
+  #
+  # Any fixtures labeled "_fixture" are safely ignored.
   class FixtureSet
     #--
     # An instance of FixtureSet is normally stored in a single YAML file and
@@ -578,21 +592,16 @@ module ActiveRecord
       @name     = name
       @path     = path
       @config   = config
-      @model_class = nil
 
-      if class_name.is_a?(Class) # TODO: Should be an AR::Base type class, or any?
-        @model_class = class_name
-      else
-        @model_class = class_name.safe_constantize if class_name
-      end
+      self.model_class = class_name
+
+      @fixtures = read_fixture_files(path)
 
       @connection  = connection
 
       @table_name = ( model_class.respond_to?(:table_name) ?
                       model_class.table_name :
                       self.class.default_fixture_table_name(name, config) )
-
-      @fixtures = read_fixture_files path, @model_class
     end
 
     def [](x)
@@ -761,13 +770,25 @@ module ActiveRecord
         @column_names ||= @connection.columns(@table_name).collect(&:name)
       end
 
-      def read_fixture_files(path, model_class)
+      def model_class=(class_name)
+        if class_name.is_a?(Class) # TODO: Should be an AR::Base type class, or any?
+          @model_class = class_name
+        else
+          @model_class = class_name.safe_constantize if class_name
+        end
+      end
+
+      # Loads the fixtures from the YAML file at +path+.
+      # If the file sets the +model_class+ and current instance value is not set,
+      # it uses the file value.
+      def read_fixture_files(path)
         yaml_files = Dir["#{path}/{**,*}/*.yml"].select { |f|
           ::File.file?(f)
         } + [yaml_file_path(path)]
 
         yaml_files.each_with_object({}) do |file, fixtures|
           FixtureSet::File.open(file) do |fh|
+            self.model_class ||= fh.model_class if fh.model_class
             fh.each do |fixture_name, row|
               fixtures[fixture_name] = ActiveRecord::Fixture.new(row, model_class)
             end
diff --git a/activerecord/test/cases/fixture_set/file_test.rb b/activerecord/test/cases/fixture_set/file_test.rb
index 92efa8aca7..242e7a9bec 100644
--- a/activerecord/test/cases/fixture_set/file_test.rb
+++ b/activerecord/test/cases/fixture_set/file_test.rb
@@ -123,6 +123,18 @@ END
         end
       end
 
+      def test_removes_fixture_config_row
+        File.open(::File.join(FIXTURES_ROOT, 'other_posts.yml')) do |fh|
+          assert_equal(['second_welcome'], fh.each.map { |name, _| name })
+        end
+      end
+
+      def test_extracts_model_class_from_config_row
+        File.open(::File.join(FIXTURES_ROOT, 'other_posts.yml')) do |fh|
+          assert_equal 'Post', fh.model_class
+        end
+      end
+
       private
       def tmp_yaml(name, contents)
         t = Tempfile.new name
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index e3c4bd9f4a..a0eaa66e94 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -7,15 +7,16 @@ require 'models/binary'
 require 'models/book'
 require 'models/bulb'
 require 'models/category'
+require 'models/comment'
 require 'models/company'
 require 'models/computer'
 require 'models/course'
 require 'models/developer'
+require 'models/doubloon'
 require 'models/joke'
 require 'models/matey'
 require 'models/parrot'
 require 'models/pirate'
-require 'models/doubloon'
 require 'models/post'
 require 'models/randomly_named_c1'
 require 'models/reply'
@@ -516,6 +517,38 @@ class OverRideFixtureMethodTest < ActiveRecord::TestCase
   end
 end
 
+class FixtureWithSetModelClassTest < ActiveRecord::TestCase
+  fixtures :other_posts, :other_comments
+
+  # Set to false to blow away fixtures cache and ensure our fixtures are loaded
+  # and thus takes into account the +set_model_class+.
+  self.use_transactional_tests = false
+
+  def test_uses_fixture_class_defined_in_yaml
+    assert_kind_of Post, other_posts(:second_welcome)
+  end
+
+  def test_loads_the_associations_to_fixtures_with_set_model_class
+    post = other_posts(:second_welcome)
+    comment = other_comments(:second_greetings)
+    assert_equal [comment], post.comments
+    assert_equal post, comment.post
+  end
+end
+
+class SetFixtureClassPrevailsTest < ActiveRecord::TestCase
+  set_fixture_class bad_posts: Post
+  fixtures :bad_posts
+
+  # Set to false to blow away fixtures cache and ensure our fixtures are loaded
+  # and thus takes into account the +set_model_class+.
+  self.use_transactional_tests = false
+
+  def test_uses_set_fixture_class
+    assert_kind_of Post, bad_posts(:bad_welcome)
+  end
+end
+
 class CheckSetTableNameFixturesTest < ActiveRecord::TestCase
   set_fixture_class :funny_jokes => Joke
   fixtures :funny_jokes
diff --git a/activerecord/test/fixtures/bad_posts.yml b/activerecord/test/fixtures/bad_posts.yml
new file mode 100644
index 0000000000..addee8e3bf
--- /dev/null
+++ b/activerecord/test/fixtures/bad_posts.yml
@@ -0,0 +1,9 @@
+# Please do not use this fixture without `set_fixture_class` as Post
+
+_fixture:
+  model_class: BadPostModel
+
+bad_welcome:
+  author_id: 1
+  title: Welcome to the another weblog
+  body: It's really nice today
diff --git a/activerecord/test/fixtures/other_comments.yml b/activerecord/test/fixtures/other_comments.yml
new file mode 100644
index 0000000000..55e8216ec7
--- /dev/null
+++ b/activerecord/test/fixtures/other_comments.yml
@@ -0,0 +1,6 @@
+_fixture:
+  model_class: Comment
+
+second_greetings:
+  post: second_welcome
+  body: Thank you for the second welcome
diff --git a/activerecord/test/fixtures/other_posts.yml b/activerecord/test/fixtures/other_posts.yml
new file mode 100644
index 0000000000..39ff763547
--- /dev/null
+++ b/activerecord/test/fixtures/other_posts.yml
@@ -0,0 +1,7 @@
+_fixture:
+  model_class: Post
+
+second_welcome:
+  author_id: 1
+  title: Welcome to the another weblog
+  body: It's really nice today