Adding watchr script, adding some tests, reducing the complexity of t…

…he add method.

.gitignore

@@ -3,5 +3,6 @@
 /bin
 /coverage
 /doc
+/tmp
 /.bundle
 /.yardoc

Gemfile.lock

@@ -23,6 +23,7 @@ GEM
     diff-lcs (1.2.4)
     ffi (1.8.1)
     i18n (0.6.1)
+    iobuffer (1.1.2)
     libusb (0.3.4)
       ffi (>= 1.0)
     method_source (0.8.1)
@@ -35,6 +36,8 @@ GEM
     redcarpet (2.3.0)
     rest-client (1.6.7)
       mime-types (>= 1.16)
+    rev (0.3.2)
+      iobuffer (>= 0.1.3)
     rspec (2.13.0)
       rspec-core (~> 2.13.0)
       rspec-expectations (~> 2.13.0)
@@ -50,6 +53,7 @@ GEM
     simplecov-html (0.7.1)
     slop (3.4.5)
     thor (0.18.1)
+    watchr (0.7)
     yard (0.8.6.1)
 
 PLATFORMS
@@ -60,5 +64,7 @@ DEPENDENCIES
   lego-nxt!
   pry (~> 0.9.12.2)
   redcarpet (~> 2.3.0)
+  rev (~> 0.3.2)
   rspec (~> 2.13.0)
+  watchr (~> 0.7.0)
   yard (~> 0.8.6.1)

lego-nxt.gemspec

@@ -16,7 +16,9 @@ Gem::Specification.new do |spec|
   spec.add_dependency('serialport', '~>1.1.0')
   spec.add_development_dependency('coveralls', '~>0.6.7')
   spec.add_development_dependency('redcarpet', '~>2.3.0')
+  spec.add_development_dependency('rev', '~>0.3.2')
   spec.add_development_dependency('rspec', '~>2.13.0')
   spec.add_development_dependency('pry', '~>0.9.12.2')
+  spec.add_development_dependency('watchr', '~>0.7.0')
   spec.add_development_dependency('yard', '~>0.8.6.1')
 end

lib/nxt/nxt_brick.rb

@@ -20,6 +20,7 @@
 #   nxt.disconnect
 class NXTBrick
   include NXT::Exceptions
+  include NXT::Utils::Assertions
 
   # An enumeration of possible ports, both input and output, that the NXT brick
   # can have connectors attached to.
@@ -90,45 +91,28 @@ def disconnect
   #                    be, though it must be able to hook in correctly
   #                    with the NXT library.
   def add(port, identifier, klass)
-    raise TypeError.new('Expected port to be a Symbol') unless port.is_a?(Symbol)
-    raise TypeError.new('Expected identifier to be a Symbol') unless identifier.is_a?(Symbol)
-    raise TypeError.new('Expected klass to be a Class') unless klass.is_a?(Class)
+    assert_in('port', port, PORTS)
+    assert_responds_to('identifier', identifier, :to_sym)
+    assert_type('klass', klass, Class)
 
-    unless PORTS.include?(port)
-      raise TypeError.new("Expected port to be one of: :#{PORTS.join(', :')}")
-    end
-
-    port_variable = :"@#{port}"
-
-    if !self.respond_to?(identifier)
-      # Makes a new instance of the class and pushes it into our instance variable
-      # for the given port.
-      self.instance_variable_set(port_variable, klass.new(port, self.interface))
-
-      # Given that that succeeded, all that remains is to add the identifier
-      # to our lookup Hash. We'll use this Hash later on within method_missing.
-      @port_identifiers[identifier] = port
-
-      # Define a method on the eigenclass of this instance.
-      (class << self; self; end).send(:define_method, identifier) do
-        self.instance_variable_get(port_variable)
-      end
-    else
-      if !self.instance_variable_get(port_variable).nil?
-        raise PortTakenError.new("Port #{port} is already set, call remove first")
-      else
+    if self.respond_to?(identifier)
+      if self.instance_variable_get(:"@#{port}").nil?
         raise InvalidIdentifierError.new("Cannot use identifier #{identifier}, a method on #{self.class} is already using it.")
+      else
+        raise PortTakenError.new("Port #{port} is already set, call remove first")
       end
     end
+
+    define_port_handler_method(port, identifier, klass)
   end
 
   # Remove the assigned (if any) connector instance from the given
   # identifier.
   #
   # @param Symbol identifier The identifier to search for and remove.
   def remove(identifier)
-    raise TypeError.new('Expected identifier to be a Symbol') unless identifier.is_a?(Symbol)
-    !!@port_identifiers.delete(identifier)
+    assert_responds_to('identifier', identifier, :to_sym)
+    !!@port_identifiers.delete(identifier.to_sym)
   end
 
   # This will dynamically add methods like:
@@ -150,4 +134,23 @@ def remove(identifier)
       end
     end
   end
+
+  private
+
+  def define_port_handler_method(port, identifier, klass)
+    port_variable = :"@#{port}"
+
+    # Makes a new instance of the class and pushes it into our instance variable
+    # for the given port.
+    self.instance_variable_set(port_variable, klass.new(port, self.interface))
+
+    # Given that that succeeded, all that remains is to add the identifier
+    # to our lookup Hash. We'll use this Hash later on within method_missing.
+    @port_identifiers[identifier.to_sym] = port
+
+    # Define a method on the eigenclass of this instance.
+    (class << self; self; end).send(:define_method, identifier.to_sym) do
+      self.instance_variable_get(port_variable)
+    end
+  end
 end

lib/nxt/utils/assertions.rb

@@ -2,9 +2,19 @@ module NXT
   module Utils
     module Assertions
       def assert_in(name, value, values)
-        unless values.include?(value)
-          raise TypeError.new("Expected #{name} to be one of: :#{values.join(', :')}")
+        raise TypeError.new("Expected #{name} to be one of: :#{values.join(', :')}") unless values.include?(value)
+      end
+
+      def assert_type(name, value, type)
+        raise TypeError.new("Expected #{name} to be of type #{type}") unless value.is_a?(type)
+      end
+
+      def assert_responds_to(name, value, *methods)
+        valid = methods.all? do |method|
+          value.respond_to?(method)
         end
+
+        raise TypeError.new("Expected #{name} to respond to: #{methods.join(', ')}") unless valid
       end
     end
   end

spec/nxt/nxt_brick_spec.rb

@@ -78,22 +78,8 @@
   end
 
   describe '#add' do
-    it 'should raise an exception if an invalid type of port is given' do
-      expect do
-        subject.add('not a symbol', :symbol, Class)
-      end.to raise_exception(TypeError, 'Expected port to be a Symbol')
-    end
-
-    it 'should raise an exception if an invalid type of identifier is given' do
-      expect do
-        subject.add(:symbol, 'not a symbol', Class)
-      end.to raise_exception(TypeError, 'Expected identifier to be a Symbol')
-    end
-
-    it 'should raise an exception if an invalid type of klass is given' do
-      expect do
-        subject.add(:symbol, :symbol, 'not a class')
-      end.to raise_exception(TypeError, 'Expected klass to be a Class')
+    before do
+      subject.stub(:define_port_handler_method)
     end
 
     it 'should raise an exception if an invalid port number or letter is given' do
@@ -102,18 +88,16 @@
       end.to raise_exception(TypeError, 'Expected port to be one of: :a, :b, :c, :one, :two, :three, :four')
     end
 
-    it 'should create a new instance of the passed klass and store it in the attribute for the given port' do
-      port = :a
-      class_stub = Class.new
-      class_return_stub = stub()
-
-      class_stub.should_receive(:new) do
-        class_return_stub
-      end.with(port, an_instance_of(NXT::Interface::Usb)).once()
-
-      subject.add(port, :hello, class_stub)
+    it 'should raise an exception if an invalid type of identifier is given' do
+      expect do
+        subject.add(:a, 123, Class)
+      end.to raise_exception(TypeError, 'Expected identifier to respond to: to_sym')
+    end
 
-      subject.send(port).should equal(class_return_stub)
+    it 'should raise an exception if an invalid type of klass is given' do
+      expect do
+        subject.add(:a, :symbol, 'not a class')
+      end.to raise_exception(TypeError, 'Expected klass to be of type Class')
     end
 
     it 'should raise an exception if the port given is already set' do
@@ -142,23 +126,15 @@
       end.to raise_error(InvalidIdentifierError, "Cannot use identifier #{identifier}, a method on NXTBrick is already using it.")
     end
 
-    it 'should set up the port identifiers correctly' do
-      port = :a
-      identifier = :hello_world
-      class_stub = Class.new
-      class_stub.stub(:new)
-
-      subject.add(port, identifier, class_stub)
-
-      subject.port_identifiers[identifier].should equal(port)
+    it 'should call #define_port_handler_method' do
     end
   end
 
   describe '#remove' do
     it 'should raise an exception if an invalid type of identifier is given' do
       expect do
-        subject.remove('not a symbol')
-      end.to raise_exception(TypeError, 'Expected identifier to be a Symbol')
+        subject.remove(123)
+      end.to raise_exception(TypeError, 'Expected identifier to respond to: to_sym')
     end
 
     it 'should remove any matching identifiers' do
@@ -185,4 +161,31 @@
       return_value.should be_false
     end
   end
+
+  describe '#define_port_handler_method' do
+    it 'should create a new instance of the passed klass and store it in the attribute for the given port' do
+      port = :a
+      class_stub = Class.new
+      class_return_stub = stub()
+
+      class_stub.should_receive(:new) do
+        class_return_stub
+      end.with(port, an_instance_of(NXT::Interface::Usb)).once()
+
+      subject.send(:define_port_handler_method, port, :hello, class_stub)
+
+      subject.send(port).should equal(class_return_stub)
+    end
+
+    it 'should set up the port identifiers correctly' do
+      port = :a
+      identifier = :hello_world
+      class_stub = Class.new
+      class_stub.stub(:new)
+
+      subject.send(:define_port_handler_method, port, identifier, class_stub)
+
+      subject.port_identifiers[identifier].should equal(port)
+    end
+  end
 end

watchr.rb

@@ -0,0 +1,2 @@
+watch('spec/.*_spec\.rb') { |md| system("rspec #{md[0]}") }
+watch('lib/(.*)\.rb') { |md| system("rspec spec/#{md[1]}_spec.rb") }