Write tests and fix implementation

lib/pragma/operation.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
+require 'interactor'
+
 require 'pragma/operation/version'
+require 'pragma/operation/base'
 
 module Pragma
   # Operations provide business logic encapsulation for your JSON API.

lib/pragma/operation/base.rb

@@ -67,14 +67,18 @@ class Base
         511 => :network_authentication_required
       }.freeze
 
-      before :setup_context
+      def self.inherited(child)
+        child.class_eval do
+          before :setup_context
 
-      around :handle_halt
+          around :handle_halt
 
-      after :set_default_status
-      after :validate_status
-      after :consolidate_status
-      after :mark_result
+          after :mark_result
+          after :consolidate_status
+          after :validate_status
+          after :set_default_status
+        end
+      end
 
       # Runs the operation.
       def call
@@ -173,23 +177,42 @@ def consolidate_status
       end
 
       def mark_result
-        return if /\A(2|3)\d{2}\z/ =~ STATUSES.invert[context.status]
+        return if /\A(2|3)\d{2}\z/ =~ STATUSES.invert[context.status].to_s
         context.fail!
       end
 
-      # This error is raised when an invalid status is set for an operation.
-      #
-      # @author Alessandro Desantis
-      class InvalidStatusError < StandardError
-        # Initializes the error.
-        #
-        # @param [Integer|Symbol] an invalid HTTP status code
-        def initialize(status)
-          super "'#{status}' is not a valid HTTP status code."
+      def with_hooks
+        # This overrides the default behavior, which is not to run after hooks if an exception is
+        # raised either in +#call+ or one of the before hooks. See:
+        # https://github.com/collectiveidea/interactor/blob/master/lib/interactor/hooks.rb#L210)
+        run_around_hooks do
+          begin
+            run_before_hooks
+            yield
+          ensure
+            run_after_hooks
+          end
         end
       end
+    end
+
+    # This error is raised when an invalid status is set for an operation.
+    #
+    # @author Alessandro Desantis
+    class InvalidStatusError < StandardError
+      # Initializes the error.
+      #
+      # @param [Integer|Symbol] an invalid HTTP status code
+      def initialize(status)
+        super "'#{status}' is not a valid HTTP status code."
+      end
+    end
 
-      Halt = StandardError
+    # This error is raised when the operation's execution should be stopped. It is silently
+    # rescued by the operation.
+    #
+    # @author Alessandro Desantis
+    class Halt < StandardError
     end
   end
 end

spec/pragma/operation/base_spec.rb

@@ -0,0 +1,100 @@
+# frozen_string_literal: true
+RSpec.describe Pragma::Operation::Base do
+  let(:operation) do
+    Class.new(described_class) do
+      before :validate_params
+
+      def call
+        respond_with(
+          status: 200,
+          resource: { pong: params[:pong] }
+        )
+      end
+
+      private
+
+      def validate_params
+        return unless params[:pong].empty?
+
+        respond_with!(
+          status: 422,
+          resource: {
+            error_type: :missing_pong,
+            error_message: "You must provide a 'pong' parameter."
+          }
+        )
+      end
+    end
+  end
+
+  let(:params) { { pong: 'HELLO' } }
+  let(:context) { operation.call(params: params) }
+
+  it 'converts numeric status codes into symbols' do
+    expect(context.status).to eq(:ok)
+  end
+
+  context 'when the response status is invalid' do
+    let(:operation) do
+      Class.new(described_class) do
+        def call
+          head :invalid
+        end
+      end
+    end
+
+    it 'raises an InvalidStatusError' do
+      expect { context }.to raise_error(Pragma::Operation::InvalidStatusError)
+    end
+  end
+
+  context 'when the operation does not set a status code' do
+    let(:operation) do
+      Class.new(described_class) do
+        def call
+          respond_with status: nil, resource: params[:resource]
+        end
+      end
+    end
+
+    context 'when a resource is set' do
+      let(:params) { { resource: 'HELLO' } }
+
+      it 'sets the 200 OK status code' do
+        expect(context.status).to eq(:ok)
+      end
+    end
+
+    context 'when a resource is not set' do
+      let(:params) { {} }
+
+      it 'sets the 204 No Content status code' do
+        expect(context.status).to eq(:no_content)
+      end
+    end
+  end
+
+  describe '#respond_with!' do
+    let(:params) { { pong: '' } }
+
+    it 'halts the execution' do
+      expect(context.status).to eq(:unprocessable_entity)
+    end
+  end
+
+  describe '#success?' do
+    context 'when the HTTP status code is successful' do
+      it 'returns true' do
+        expect(context).to be_success
+      end
+    end
+
+    context 'when the HTTP status code is not successful' do
+      let(:params) { { pong: '' } }
+
+      it 'returns false' do
+        expect(context).not_to be_success
+      end
+    end
+  end
+end