TirePressureMonitoringSystem/Ruby: synchronised the code with the ori…

…ginal C# version, minor syntax style improvements.

TDDMicroExercises/Ruby/tire_pressure_monitoring_system/alarm.rb

@@ -1,24 +1,22 @@
-require_relative "./sensor"
+require_relative './sensor'
 
 class Alarm
-    LOWPRESSURETHRESHOLD = 17
-    HIGHPRESSURETHRESHOLD = 21
 
-    def initialize
-      @sensor = Sensor.new 
-      @alarm_on = false
-      @alarm_count = 0
-    end
+  attr_reader :alarm_on
 
-    def check
-      psi_pressure_value = @sensor.pop_next_pressure_psi_value
-      if psi_pressure_value < LOWPRESSURETHRESHOLD || HIGHPRESSURETHRESHOLD < psi_pressure_value 
-          @alarm_on = true
-          @alarm_count += 1
-      end
-    end
+  def initialize
+    @sensor = Sensor.new
+    @alarm_on = false
+  end
+
+  def check
+    pressure = @sensor.pop_next_pressure_psi_value()
 
-    def alarm_on 
-      return @alarm_on 
+    @alarm_on = true if pressure < LOW_PRESSURE || HIGH_PRESSURE < pressure
     end
+
+private
+
+  LOW_PRESSURE = 17
+  HIGH_PRESSURE = 21
 end

TDDMicroExercises/Ruby/tire_pressure_monitoring_system/alarm_test.rb

@@ -0,0 +1,9 @@
+require 'test/unit'
+require_relative './alarm'
+
+class AlarmTest < Test::Unit::TestCase
+  def test_do_something
+    alarm = Alarm.new
+    alarm.check
+  end
+end

TDDMicroExercises/Ruby/tire_pressure_monitoring_system/sensor.rb

@@ -1,15 +1,16 @@
 class Sensor
-    OFFSET = 16;
+  # The reading of the pressure value from the sensor is simulated in this implementation.
+  # Because the focus of the exercise is on the other class.
 
-    def pop_next_pressure_psi_value 
-      pressure_telemetry_value = sample_pressure 
-      OFFSET + pressure_telemetry_value;
-    end
+  OFFSET = 16
+  private_constant :OFFSET
 
-    def sample_pressure 
-      #placeholder implementation that 
-      #simulate a real sensor in a real tire
-      pressure_telemetry_value = 6 * rand(5) * rand(4) 
-      pressure_telemetry_value
-    end
+  def pop_next_pressure_psi_value
+    OFFSET + read_sample_pressure()
+  end
+
+  def read_sample_pressure
+    #Simulate info read from a real sensor in a real tire
+    6 * rand * rand
+  end
 end