Fixes issue with ActiveStorage::FixtureSet.blob erroring because Acti…

…veStorage::FixtureSet.file_fixture_path is not set.

features/file_fixture.feature

@@ -36,3 +36,21 @@ Feature: Using `file_fixture`
       """
     When I run `rspec spec/lib/file_spec.rb`
     Then the examples should all pass
+
+  Scenario: Creating a ActiveStorage::Blob from a file fixture
+    Given a file named "spec/fixtures/files/sample.txt" with:
+      """
+      Hello
+      """
+    And a file named "spec/lib/fixture_set_blob.rb" with:
+      """ruby
+      require "rails_helper"
+
+      RSpec.describe "blob" do
+        it "creates a blob from a sample file" do
+          expect(ActiveStorage::FixtureSet.blob(filename: "sample.txt")).to include("sample.txt")
+        end
+      end
+      """
+    When I run `rspec spec/lib/fixture_set_blob.rb`
+    Then the examples should all pass

lib/rspec/rails/file_fixture_support.rb

@@ -9,6 +9,9 @@ module FileFixtureSupport
 
       included do
         self.file_fixture_path = RSpec.configuration.file_fixture_path
+        if defined? ActiveStorage::FixtureSet
+          ActiveStorage::FixtureSet.file_fixture_path = RSpec.configuration.file_fixture_path
+        end
       end
     end
   end