Add CapabilityConfig resource methods

Convinient methods to get the CapabilityConfig instance
of a given resource

lib/resource_registry/capabilities/capability_config.rb

@@ -22,12 +22,22 @@ module ClassMethods
         def key
         end
 
-        sig { params(resource: Resource).returns(T.nilable(self))}
+        sig { params(resource: Resource).returns(T::Boolean) }
+        def resource_capability?(resource:)
+          resource.capabilities.key?(key)
+        end
+
+        sig { params(resource: Resource).returns(T.nilable(T.self_type))}
         def resource_capability(resource:)
-          return unless resource.capabilities.key?(key)
+          return unless resource_capability?(resource:)
 
           T.cast(resource.capabilities[key], self)
         end
+
+        sig { params(resource: Resource).returns(T.self_type)}
+        def resource_capability!(resource:)
+          T.must(resource_capability(resource: ))
+        end
       end
 
       requires_ancestor { Object }

spec/resource_registry/capabilities/capability_config_spec.rb

@@ -0,0 +1,55 @@
+# typed: false
+
+require "spec_helper"
+require_relative "../../../lib/resource_registry/capabilities/capability_config"
+
+class DummyCapability < T::Struct
+  include ResourceRegistry::Capabilities::CapabilityConfig
+
+  def self.key
+    :dummy_capability
+  end
+end
+
+RSpec.describe ResourceRegistry::Capabilities::CapabilityConfig do
+  let(:schema) do
+    SchemaRegistry::Schema.new(
+      name: "dummy",
+      namespace: "dummies",
+      properties: [
+        SchemaRegistry::Property.new(
+          name: "foo",
+          types: [SchemaRegistry::PropertyType::String],
+          required: true
+        )
+      ]
+    )
+  end
+  let(:capabilities) { { dummy_capability: DummyCapability.new } }
+  let(:resource) do
+    ResourceRegistry::Resource.new(
+      repository_raw: DummyRepo.to_s,
+      capabilities:,
+      verbs: {
+      },
+      schema:
+    )
+  end
+
+  it "should return resource's capability" do
+    expect(DummyCapability.resource_capability?(resource:)).to be true
+    expect(DummyCapability.resource_capability(resource:)).to be_a(DummyCapability)
+    expect(DummyCapability.resource_capability!(resource:)).to be_a(DummyCapability)
+  end
+
+  context 'without the capability' do
+    let(:capabilities) { {} }
+
+    it "should return resource's capability" do
+      expect(DummyCapability.resource_capability?(resource:)).to be false
+      expect(DummyCapability.resource_capability(resource:)).to be_nil
+    end
+  end
+end
+
+