Nest describe blocks

message_filter_spec.rb

@@ -1,17 +1,17 @@
 require_relative 'message_filter'
 
-shared_examples 'MessageFilter with argument "foo"' do
-  it { is_expected.to be_detect('hello from foo') }
-  it { is_expected.not_to be_detect('hello, world!') }
+describe MessageFilter do
+  shared_examples 'MessageFilter with argument "foo"' do
+    it { is_expected.to be_detect('hello from foo') }
+    it { is_expected.not_to be_detect('hello, world!') }
+  end
+  describe 'with argument "foo"' do
+    subject { MessageFilter.new('foo') }
+    it_behaves_like 'MessageFilter with argument "foo"'
+  end
+  describe 'with argument "foo","bar"' do
+    subject { MessageFilter.new('foo', 'bar') }
+    it { is_expected.to be_detect('hello from bar') }
+    it_behaves_like 'MessageFilter with argument "foo"'
+  end
 end
-
-describe MessageFilter, 'with argument "foo"' do
-  subject { MessageFilter.new('foo') }
-  it_behaves_like 'MessageFilter with argument "foo"'
-end
-
-describe MessageFilter, 'with argument "foo","bar"' do
-  subject { MessageFilter.new('foo', 'bar') }
-  it { is_expected.to be_detect('hello from bar') }
-  it_behaves_like 'MessageFilter with argument "foo"'
-end