introduce `ActiveSupport::Testing::FileFixtures`.

It's a thin layer to provide easy access to sample files throughout
test-cases. This adds the directory `test/fixtures/files` to newly
generated applications.

1 files changed, 34 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/testing/file_fixtures.rb b/activesupport/lib/active_support/testing/file_fixtures.rb
new file mode 100644
index 0000000000..4c6a0801b8
--- /dev/null
+++ b/activesupport/lib/active_support/testing/file_fixtures.rb
@@ -0,0 +1,34 @@
+module ActiveSupport
+  module Testing
+    # Adds simple access to sample files called file fixtures.
+    # File fixtures are normal files stored in
+    # <tt>ActiveSupport::TestCase.file_fixture_path</tt>.
+    #
+    # File fixtures are represented as +Pathname+ objects.
+    # This makes it easy to extract specific information:
+    #
+    #   file_fixture("example.txt").read # get the file's content
+    #   file_fixture("example.mp3").size # get the file size
+    module FileFixtures
+      extend ActiveSupport::Concern
+
+      included do
+        class_attribute :file_fixture_path, instance_writer: false
+      end
+
+      # Returns a +Pathname+ to the fixture file named +fixture_name+.
+      #
+      # Raises ArgumentError if +fixture_name+ can't be found.
+      def file_fixture(fixture_name)
+        path = Pathname.new(File.join(file_fixture_path, fixture_name))
+
+        if path.exist?
+          path
+        else
+          msg = "the directory '%s' does not contain a file named '%s'"
+          raise ArgumentError, msg % [file_fixture_path, fixture_name]
+        end
+      end
+    end
+  end
+end