Use Kernel#throw as success interrupter (#7)

* Remove Success Interruption, use Kernel#throw instead

* Add spec for rollback operation

* Add specs for failure

* More checks

* Remove value from success

* Fix bug with catching thows of other classes

* Fix bugs found in discus

Author: AnotherRegularDude

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    resol (0.5.1)
+    resol (0.6.0)
       smart_initializer (~> 0.7)
 
 GEM
@@ -131,4 +131,4 @@ DEPENDENCIES
   simplecov-lcov
 
 BUNDLED WITH
-   2.2.19
+   2.2.21

lib/resol/service.rb

@@ -8,58 +8,47 @@ module Resol
   class Service
     class InvalidCommandImplementation < StandardError; end
 
-    class Interruption < StandardError
-      attr_accessor :data
+    class Failure < StandardError
+      attr_accessor :data, :code
 
-      def initialize(data)
+      def initialize(code, data)
+        self.code = code
         self.data = data
-        super
+        super(data)
       end
 
       def inspect
         "#{self.class.name}: #{message}"
       end
 
-      def message
-        data.inspect
-      end
-    end
-
-    class Failure < Interruption
-      attr_accessor :code
-
-      def initialize(code, data)
-        self.code = code
-        super(data)
-      end
-
       def message
         data ? "#{code.inspect} => #{data.inspect}" : code.inspect
       end
     end
 
-    class Success < Interruption; end
-
     include SmartCore::Initializer
     include Resol::Builder
     include Resol::Callbacks
 
+    Result = Struct.new(:data)
+
     class << self
       def inherited(klass)
         klass.const_set(:Failure, Class.new(klass::Failure))
-        klass.const_set(:Success, Class.new(klass::Success))
         super
       end
 
       def call(*args, **kwargs, &block)
         command = build(*args, **kwargs)
-        __run_callbacks__(command)
-        command.call(&block)
+        result = catch(command) do
+          __run_callbacks__(command)
+          command.call(&block)
+          nil
+        end
+        return Resol::Success(result.data) unless result.nil?
 
         error_message = "No success! or fail! called in the #call method in #{command.class}"
         raise InvalidCommandImplementation, error_message
-      rescue self::Success => e
-        Resol::Success(e.data)
       rescue self::Failure => e
         Resol::Failure(e)
       end
@@ -78,7 +67,7 @@ def fail!(code, data = nil)
     end
 
     def success!(data = nil)
-      raise self.class::Success.new(data)
+      throw(self, Result.new(data))
     end
   end
 end

lib/resol/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Resol
-  VERSION = "0.5.1"
+  VERSION = "0.6.0"
 end

spec/interruptions_spec.rb

@@ -1,28 +1,19 @@
 # frozen_string_literal: true
 
-RSpec.describe Resol::Service::Interruption do
-  describe Resol::Service::Success do
-    let(:object) { Resol::Service::Success.new(:some_data) }
+RSpec.describe Resol::Service::Failure do
+  let(:object) { Resol::Service::Failure.new(:some_data, data) }
 
-    it { expect(object.inspect).to eq("Resol::Service::Success: :some_data") }
+  context "without data" do
+    let(:data) { nil }
+
+    it { expect(object.inspect).to eq("Resol::Service::Failure: :some_data") }
     it { expect(object.message).to eq(":some_data") }
   end
 
-  describe Resol::Service::Failure do
-    let(:object) { Resol::Service::Failure.new(:some_data, data) }
-
-    context "without data" do
-      let(:data) { nil }
-
-      it { expect(object.inspect).to eq("Resol::Service::Failure: :some_data") }
-      it { expect(object.message).to eq(":some_data") }
-    end
-
-    context "with data" do
-      let(:data) { :data }
+  context "with data" do
+    let(:data) { :data }
 
-      it { expect(object.inspect).to eq("Resol::Service::Failure: :some_data => :data") }
-      it { expect(object.message).to eq(":some_data => :data") }
-    end
+    it { expect(object.inspect).to eq("Resol::Service::Failure: :some_data => :data") }
+    it { expect(object.message).to eq(":some_data => :data") }
   end
 end

spec/service_spec.rb

@@ -1,5 +1,23 @@
 # frozen_string_literal: true
 
+class DB
+  class << self
+    attr_accessor :rollbacked
+
+    def transaction
+      self.rollbacked = false
+
+      yield
+      "return_some_val"
+      # rubocop:disable Lint/RescueException
+    rescue Exception
+      # rubocop:enable Lint/RescueException
+      self.rollbacked = true
+      raise
+    end
+  end
+end
+
 class SuccessService < Resol::Service
   def call
     success!(:success_result)
@@ -13,7 +31,9 @@ def call
 end
 
 class EmptyService < Resol::Service
-  def call; end
+  def call
+    "some_string"
+  end
 end
 
 class ServiceWithCallbacks < Resol::Service
@@ -40,6 +60,27 @@ def set_other_value
   end
 end
 
+class ServiceWithTransaction < Resol::Service
+  def call
+    DB.transaction { success! }
+  end
+end
+
+class ServiceWithFailInTransaction < Resol::Service
+  def call
+    DB.transaction { fail!(:failed) }
+  end
+end
+
+class HackyService < Resol::Service
+  param :count
+
+  def call
+    success! unless count.zero?
+    HackyService.build(count + 1).call
+  end
+end
+
 RSpec.describe Resol::Service do
   it "returns a success result" do
     expect(SuccessService.call!).to eq(:success_result)
@@ -64,4 +105,31 @@ def set_other_value
     expect(SubServiceWithCallbacks.call!).to eq("some_value_postfix")
     expect(ServiceWithCallbacks.call!).to eq("some_value")
   end
+
+  it "doesn't rollback transaction" do
+    result = ServiceWithTransaction.call
+    expect(result.success?).to eq(true)
+    expect(result.value!).to eq(nil)
+    expect(DB.rollbacked).to eq(false)
+  end
+
+  context "when service failed" do
+    it "rollbacks transaction" do
+      result = ServiceWithFailInTransaction.call
+      expect(result.failure?).to eq(true)
+      result.or do |error|
+        expect(error.code).to eq(:failed)
+      end
+
+      expect(DB.rollbacked).to eq(true)
+    end
+  end
+
+  context "when using instance #call inside other service" do
+    let(:expected_message) { /uncaught throw #<HackyService/ }
+
+    it "raises an exception" do
+      expect { HackyService.call!(0) }.to raise_error(UncaughtThrowError, expected_message)
+    end
+  end
 end