Fix fixture declarations not propagating to auto-included shared example groups

When shared example groups are auto-included via `config.include_context`
with metadata filters, RSpec creates those child groups during
configuration — before the spec file's `fixture` call sets the
declaration on the parent group's metadata. Since RSpec snapshots parent
metadata into child groups at creation time, the child's metadata never
includes the fixture declaration, and the `prepend_before` hook never
fires for those examples.

The fix uses RSpec's own `update_inherited_metadata` to propagate the
fixture declaration to any child groups that already exist when `fixture`
is called. This is the same mechanism RSpec uses internally to push
metadata updates to descendants.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ngan

lib/fixture_kit/rspec.rb

@@ -30,7 +30,11 @@ module ClassMethods
       def fixture(name = nil, extends: nil, &block)
         definition = Definition.new(extends: extends, &block) if block_given?
         declaration = ::RSpec.configuration.fixture_kit.register(name || definition, self)
-        metadata[DECLARATION_METADATA_KEY] = declaration
+        # Use update_inherited_metadata to set the declaration on this group
+        # AND propagate to any child groups already created (e.g., shared
+        # example groups auto-included via `config.include_context` during
+        # RSpec configuration).
+        update_inherited_metadata(DECLARATION_METADATA_KEY => declaration)
 
         prepend_before(:context) do
           self.class.metadata[DECLARATION_METADATA_KEY].generate

spec/dummy/spec/integration/fixture_kit_integration.rb

@@ -12,6 +12,26 @@ module FixtureKitIntegrationTimeHelpers
   config.include(FixtureKitIntegrationTimeHelpers)
 end
 
+# Shared examples auto-included via config.include_context to reproduce the
+# ordering issue: RSpec creates the shared group during configuration (before
+# the host group's `fixture` call sets metadata), so fixture declarations
+# must propagate through runtime metadata inheritance.
+RSpec.shared_examples "auto-included shared examples" do
+  context "inside auto-included shared context" do
+    let(:shared_user) { User.find_by!(email: "alice@team.test") }
+
+    it "can access fixture data through let blocks defined in the host group" do
+      expect(fixture.alice.email).to eq("alice@team.test")
+      expect(shared_user).to eq(fixture.alice)
+      puts "FKIT_ASSERT:SHARED_EXAMPLE_FIXTURE_ACCESS"
+    end
+  end
+end
+
+RSpec.configure do |config|
+  config.include_context "auto-included shared examples", :include_shared_fixture_test
+end
+
 RSpec.describe "FixtureKit integration" do
   describe "fixture preload timing" do
     fixture "teams/basic"
@@ -220,6 +240,15 @@ module FixtureKitIntegrationTimeHelpers
     end
   end
 
+  describe "fixture with auto-included shared examples", :include_shared_fixture_test do
+    fixture "teams/basic"
+
+    it "works in the host group" do
+      expect(fixture.alice.name).to eq("Alice")
+      puts "FKIT_ASSERT:SHARED_EXAMPLE_HOST_FIXTURE"
+    end
+  end
+
   describe "fixture instance reader without declaration" do
     it "raises a helpful error message" do
       expect do

spec/integration/dummy_app_spec.rb

@@ -76,6 +76,13 @@ def run_dummy_tests
       "FKIT_ASSERT:UNDECLARED_FIXTURE_READER"
     ]
 
+    if INTEGRATION_FRAMEWORK == "rspec"
+      expected_markers += [
+        "FKIT_ASSERT:SHARED_EXAMPLE_FIXTURE_ACCESS",
+        "FKIT_ASSERT:SHARED_EXAMPLE_HOST_FIXTURE"
+      ]
+    end
+
     expected_markers.each do |marker|
       expect(output).to include(marker), "Expected marker #{marker.inspect} in output.\nOutput:\n#{output}"
     end

spec/unit/rspec_entrypoint_spec.rb

@@ -109,6 +109,10 @@ def build_group(parent_metadata = {})
         @fixture_kit_before_context_hook
       end
 
+      define_singleton_method(:update_inherited_metadata) do |updates|
+        metadata.update(updates)
+      end
+
       define_singleton_method(:append_after) do |scope, &block|
         raise "Unexpected scope: #{scope}" unless scope == :context