Add ensure hook

lib/interactor/hooks.rb

@@ -127,6 +127,11 @@ def after(*hooks, &block)
         hooks.each { |hook| after_hooks.unshift(hook) }
       end
 
+      def ensure_hook(*hooks, &block)
+        hooks << block if block
+        hooks.each { |hook| ensure_hooks.push(hook) }
+      end
+
       # Internal: An Array of declared hooks to run around Interactor
       # invocation. The hooks appear in the order in which they will be run.
       #
@@ -183,6 +188,10 @@ def before_hooks
       def after_hooks
         @after_hooks ||= []
       end
+
+      def ensure_hooks
+        @ensure_hooks ||= []
+      end
     end
 
     private
@@ -213,6 +222,8 @@ def with_hooks
         yield
         run_after_hooks
       end
+    ensure
+      run_ensure_hooks
     end
 
     # Internal: Run around hooks.
@@ -238,6 +249,10 @@ def run_after_hooks
       run_hooks(self.class.after_hooks)
     end
 
+    def run_ensure_hooks
+      run_hooks(self.class.ensure_hooks)
+    end
+
     # Internal: Run a colection of hooks. The "run_hooks" method is the common
     # interface by which collections of either before or after hooks are run.
     #

spec/interactor/hooks_spec.rb

@@ -24,6 +24,40 @@ def process
         hooked
       end
 
+      context "with an ensure hook method" do
+        let(:hooked) {
+          build_hooked do
+            before :add_before
+            after :add_after_with_error
+            ensure_hook :add_ensure
+
+            def self.context
+              @context ||= OpenStruct.new
+            end
+
+            private
+
+            def add_before
+              self.class.context.resource = 1
+            end
+
+            def add_after_with_error
+              raise 'something wrong has happened'
+            end
+
+            def add_ensure
+              self.class.context.resource = 0
+            end
+          end
+        }
+
+        it "runs the ensure hook block" do
+          expect { hooked.process }.to raise_error('something wrong has happened')
+
+          expect(hooked.context.resource).to eq 0
+        end
+      end
+
       context "with an around hook method" do
         let(:hooked) {
           build_hooked do