Replace () by []

Author: ericproulx

CHANGELOG.md

@@ -7,6 +7,7 @@
 
 #### Fixes
 
+* [#2633](https://github.com/ruby-grape/grape/pull/2633): Fix cascade reading - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 ### 3.0.1 (2025-11-24)

lib/grape/api/instance.rb

@@ -78,7 +78,7 @@ def call!(env)
 
         # (see #cascade?)
         def cascade(value = nil)
-          return inheritable_setting.namespace_inheritable.key?(:cascade) ? !inheritable_setting.namespace_inheritable(:cascade).nil? : true if value.nil?
+          return inheritable_setting.namespace_inheritable.key?(:cascade) ? !inheritable_setting.namespace_inheritable[:cascade].nil? : true if value.nil?
 
           inheritable_setting.namespace_inheritable[:cascade] = value
         end

spec/grape/api_spec.rb

@@ -4722,4 +4722,16 @@ def uniqe_id_route
       expect { get '/' }.to raise_error(Rack::Lint::LintError)
     end
   end
+
+  describe '.cascade' do
+    subject { api.cascade }
+
+    let(:api) do
+      Class.new(Grape::API) do
+        cascade true
+      end
+    end
+
+    it { is_expected.to eq(true) }
+  end
 end