allowed decimal format for hours, this resolves #1

app/decimal_notation_strategy.py

@@ -0,0 +1,5 @@
+class DecimalNotationStrategy:
+    def calculate_minutes(self, decimal_notation_string):
+        decimal_hour = float(decimal_notation_string)
+
+        return int(decimal_hour * 60)

app/hour_notation_strategy.py

@@ -0,0 +1,14 @@
+class HourNotationStrategy:
+    def calculate_minutes(self, hour_notation_string):
+        change_sign = False
+        if hour_notation_string.startswith('-'):
+            hour_notation_string = hour_notation_string[1:]
+            change_sign = True
+
+        time_list = hour_notation_string.split(':')
+        hours = int(time_list[0])
+        minutes = int(time_list[1])
+
+        total_minutes = minutes + hours * 60
+
+        return -total_minutes if change_sign else total_minutes

app/hours_calculator.py

@@ -1,5 +1,7 @@
 from __future__ import division
 import re
+from .hour_notation_strategy import HourNotationStrategy
+from .decimal_notation_strategy import DecimalNotationStrategy
 
 
 class HoursCalculator:
@@ -16,7 +18,7 @@ def add(self, *args):
                 continue
             if not self._is_valid_format(hour):
                 return 'Invalid hour value: "{0}"'.format(hour)
-            total_minutes += self._calculate_total_minutes_from_string(hour.replace('.', ':'))
+            total_minutes += self._get_calculation_strategy(hour).calculate_minutes(hour)
 
         total_hours = int(total_minutes / 60)
         remaining_minutes = abs(total_minutes) % 60
@@ -26,19 +28,11 @@ def add(self, *args):
 
         return '{0:02d}:{1:02d}'.format(total_hours, remaining_minutes)
 
-    def _calculate_total_minutes_from_string(self, time_string):
-        change_sign = False
-        if time_string.startswith('-'):
-            time_string = time_string[1:]
-            change_sign = True
-
-        time_list = time_string.split(':')
-        hours = int(time_list[0])
-        minutes = int(time_list[1])
-
-        total_minutes = minutes + hours * 60
-
-        return -total_minutes if change_sign else total_minutes
+    def _get_calculation_strategy(self, time_string):
+        if ':' in time_string:
+            return HourNotationStrategy()
+        else:
+            return DecimalNotationStrategy()
 
     def _is_valid_format(self, hour):
         pattern = re.compile('^\s*[+-]?\d+[.:]\d+\s*$')

tests/test_hours_calculator.py

@@ -12,8 +12,8 @@ def test_add_with_no_parameters_returns_zero(self):
     def test_add_with_one_parameter_returns_that_parameter(self):
         self.assertEqual("02:53", self.calculator.add("2:53"))
 
-    def test_add_replace_dot_with_colon(self):
-        self.assertEqual("02:53", self.calculator.add("2.53"))
+    # def test_add_replace_dot_with_colon(self):
+    #     self.assertEqual("02:53", self.calculator.add("2.53"))
 
     def test_add_ignore_leading_zero(self):
         self.assertEqual("02:53", self.calculator.add("02:53"))
@@ -40,7 +40,7 @@ def test_add_two_time_values(self):
         self.assertEqual("01:15", self.calculator.add("1:15", "0:00"))
         self.assertEqual("02:15", self.calculator.add("1:15", "1:00"))
         self.assertEqual("03:15", self.calculator.add("1:15", "1:60"))
-        self.assertEqual("04:15", self.calculator.add("1:75", "01.60"))
+        self.assertEqual("04:15", self.calculator.add("1:75", "01:60"))
 
     def test_add_multiple_time_values(self):
         self.assertEqual("07:10", self.calculator.add("1:50", "2:35", "2:45"))
@@ -60,7 +60,7 @@ def test_add_positive_with_negative_hours(self):
 
     def test_add_multiple_negative_hours(self):
         self.assertEqual("-2:10", self.calculator.add("-1:10", "-1:00"))
-        self.assertEqual("-3:40", self.calculator.add("-1:10", "-1:00", "-1.30"))
+        self.assertEqual("-3:40", self.calculator.add("-1:10", "-1:00", "-1:30"))
 
     def test_large_hours_and_minutes(self):
         self.assertEqual("113:35", self.calculator.add("111:155"))
@@ -76,8 +76,22 @@ def test_ignore_blank_spaces_arround_hour_strings(self):
     def test_input_hours_as_array(self):
         self.assertEqual("-1:20", self.calculator.add(*[u'1:00', u'-2:20']))
 
+    def test_decimal_inputs(self):
+        self.assertEqual("01:30", self.calculator.add("1.5"))
+        self.assertEqual("01:12", self.calculator.add("1.2"))
+        self.assertEqual("04:42", self.calculator.add("4.7"))
+        self.assertEqual("02:42", self.calculator.add("1.2", "1.5"))
+
+    def test_negative_decimal_inputs(self):
+        self.assertEqual("-4:42", self.calculator.add("-4.7"))
+        self.assertEqual("-00:18", self.calculator.add("1.2", "-1.5"))
+
+    def test_round_down_decimal_inputs(self):
+        self.assertEqual("00:58", self.calculator.add("0.97"))
+        self.assertEqual("00:13", self.calculator.add("0.23"))
+
     def test_integration(self):
-        self.assertEqual("05:00", self.calculator.add("1:65", "-1.00", '4.70', '-0.75'))
+        self.assertEqual("05:02", self.calculator.add("1:65", "-1.00", '4.70', '-0.75'))
 
     def test_invalid_inputs_return_NaN_string(self):
         self.assertEqual("Invalid hour value: \"1:1:65\"", self.calculator.add("1:1:65"))