simulation: Test the divergence on Float Equivalence Tester with the epsilon-span by default

Before:
   Float Equivalence Tester does not test the divergence even if Divergence Provider is ON
    
After:
     Float Equivalence Tester test the divergence with the epsilon-span if Divergence Provider is ON
    
Before, we needed the following condition to test the divergence at Float Equivalence Tester:
    
       "Divergence Provider is ON"  AND
       ("Absolute Tolerance has some value"  OR
        "Relative Tolerance has some value" )
    
However this default behavior was not consistent with other testers, and
difficult to notice from the user interface.
Thus test the divergence by default with the epsilon span which is defined in 
FloatEquivalenceTester class.
    
The epsilon-span is the same amount that when we put 0.0 into the ranges.
The 0.0 has been the configuration of erp5_configurator_standard_trade_template.

/reviewed-on nexedi/erp5!865

product/ERP5/Document/FloatEquivalenceTester.py

@@ -117,14 +117,23 @@ class FloatEquivalenceTester(Predicate, EquivalenceTesterMixin):
     # XXX we should use appropriate property sheets and getter methods
     # for these properties.
     # Maybe, but beware of default values of quantity when doing so
-    absolute_tolerance_min = self.getProperty('quantity_range_min')
+    tolerance_base = self.getProperty('tolerance_base')
+    # If tolerance_base is None, check the divergece with epsilon-span by default
+    # If tolerance_base is not None, we can use tolerance_base (absolute has priority)
+    if tolerance_base is None:
+      absolute_tolerance_min = self.getProperty('quantity_range_min') or -epsilon
+    else:
+      absolute_tolerance_min = self.getProperty('quantity_range_min')
     if absolute_tolerance_min is not None and \
        delta < (absolute_tolerance_min or - epsilon):
       return (
         prevision_value, decision_value,
         explanation_start + 'is less than ${value}.',
         getMappingDict(value=absolute_tolerance_min))
-    absolute_tolerance_max = self.getProperty('quantity_range_max')
+    if tolerance_base is None:
+      absolute_tolerance_max = self.getProperty('quantity_range_max') or epsilon 
+    else:
+      absolute_tolerance_max = self.getProperty('quantity_range_max')
     if absolute_tolerance_max is not None and \
        delta > (absolute_tolerance_max or epsilon):
       return (
@@ -132,7 +141,6 @@ class FloatEquivalenceTester(Predicate, EquivalenceTesterMixin):
         explanation_start + 'is larger than ${value}.',
         getMappingDict(value=absolute_tolerance_max))
 
-    tolerance_base = self.getProperty('tolerance_base')
     base = None
     if tolerance_base == 'resource_quantity_precision':
       # Precision of this movement's resource base unit quantity

product/ERP5/tests/testDivergenceTester.py

@@ -31,6 +31,7 @@ from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase
 from Products.ERP5Type.tests.Sequence import Sequence
 from Products.ERP5.tests.testPackingList import TestPackingListMixin
 from Products.ERP5Type.UnrestrictedMethod import UnrestrictedMethod
+from Products.ERP5.Document.FloatEquivalenceTester import DEFAULT_PRECISION
 
 class TestDivergenceTester(TestPackingListMixin, ERP5TypeTestCase):
   """
@@ -339,6 +340,173 @@ class TestDivergenceTester(TestPackingListMixin, ERP5TypeTestCase):
     divergence_tester.setDecimalExponent('0.01')
     self.assertTrue(divergence_tester_compare(3.0, 3.001))
 
+  def stepAddDefaultRangePriceDivergenceTester(self, sequence):
+    self._addDivergenceTester(
+      sequence,
+      tester_name='price',
+      tester_type='Float Divergence Tester',
+    )
+
+  def stepCheckFloatDivergenceTesterWithTheDefaultRange(self, sequence):
+    """
+     Check Float Divergence tester behavior, especially around the
+     default range = epsilon = abs(prevision_value * DEFAULT_PRECISION)
+    """
+    divergence_tester = sequence['price_divergence_tester']
+
+    decision = sequence['order_line']
+    prevision = decision.getDeliveryRelatedValue(
+      portal_type=self.simulation_movement_portal_type)
+    def divergence_tester_compare(prevision_value, decision_value):
+      prevision.setPrice(prevision_value)
+      decision.setPrice(decision_value)
+      return divergence_tester.compare(prevision, decision)
+
+    prevision_value = 3.0
+    # Def. epsilon
+    # The is the epsilon defined by
+    # FloatEquivalenceTester._comparePrevisionDecisionValue()
+    epsilon = abs(prevision_value * DEFAULT_PRECISION)
+
+    self.assertFalse(divergence_tester.isDecimalAlignmentEnabled())
+
+    a_value_slightly_bigger_than_the_range = 3.0 + epsilon + DEFAULT_PRECISION
+    # Since
+    # delta = abs(decision - prevision)
+    # delta = (3.0 + epsilon + DEFAULT_PRECISION) - 3.0
+    #       = epsilon + DEFAULT_PRECISION
+    # epsilon + DEFAULT_PRECISION < -epsilon is False
+    # epsilon + DEFAULT_PRECISION > epsilon is True
+    # --> Diverged <=> compare() returns False
+    self.assertFalse(
+      divergence_tester_compare(3.0, a_value_slightly_bigger_than_the_range))
+
+    a_value_slightly_smaller_than_the_range = 3.0 + epsilon - DEFAULT_PRECISION
+    # Since,
+    # delta = abs(decision - prevision)
+    # delta = (3.0 + epsilon - DEFAULT_PRECISION) - 3.0
+    #       = epsilon - DEFAULT_PRECISION
+    # epsilon - DEFAULT_PRECISION < -epsilon is False
+    # epsilon - DEFAULT_PRECISION > epsilon is False
+    #   --> Not diverged <=> compare() returns True
+    self.assertTrue(
+      divergence_tester_compare(3.0, a_value_slightly_smaller_than_the_range))
+
+    the_value_equal_to_the_range = 3.0 + epsilon
+    # Since,
+    #  delta = abs(decision - prevision)
+    #  delta = (3.0 + epsilon) - 3.0
+    #        = epsilon
+    #  epsilon < -epsilon is False
+    #  epsilon > epsilon is False
+    #  -- Not diverged <=> compare() returns True
+    self.assertTrue(
+      divergence_tester_compare(3.0, the_value_equal_to_the_range))
+
+    # The behavior for absolute_range is the same when we set
+    # 0.0 for the range.
+    # That is why the default bihavior is safe since most of sample
+    # test data has 0.0 for its range.
+    self.assertFalse(divergence_tester_compare(3.0, 3.001))
+    self.assertTrue(divergence_tester_compare(3.0, 3.0))
+
+
+  def testFloatDivergenceTesterAroundTheDefaultRange(
+        self, quiet=quiet, run=run_all_test):
+    """
+     All the ranges of Float Divergence Tester:
+      - quantity_range_max,
+      - quantity_rang_min,
+      - tolerance_range_max,
+      - tolerance_range_min
+      are None by default. 0.0 is NOT the default value.
+
+      This is partly because FloatEquivalenceTester use None range as a flag
+      whether we use absolute_range or tolerance_range.
+      The logic uses the fact that 0.0 is not None, but bool(0.0) is False.
+
+      So here checking how it works around the range when they are default value
+    """
+    if not run: return
+    sequence_string = self.confirmed_order_without_packing_list + """
+          ResetDeliveringRule
+          AddDefaultRangePriceDivergenceTester
+          Tic
+          CheckFloatDivergenceTesterWithTheDefaultRange
+    """
+    sequence = Sequence(self)
+    sequence(sequence_string, quiet=self.quiet)
+
+  def stepSetNewPrice(self, sequence=None,
+                         sequence_list=None, **kw):
+    packing_list = sequence.get('packing_list')
+    movement = sequence.get('movement')
+    movement.setPrice(movement.getPrice()+1234)
+
+  def stepSetPreviousPrice(self, sequence=None,
+                           sequence_list=None, **kw):
+    simulation_movement = sequence.get('sim_mvt')
+    movement = sequence.get('movement')
+    movement.setPrice(simulation_movement.getPrice())
+
+  def stepSetPreviousPricePlusAValueSmallerThanTheEpsilon(
+        self, sequence=None, sequence_list=None, **kw):
+    simulation_movement = sequence.get('sim_mvt')
+    movement = sequence.get('movement')
+    prevision = simulation_movement.getPrice()
+    self.assertEqual(prevision, 555.0)
+    self.assertEqual(DEFAULT_PRECISION, 1e-12)
+    # Since the epsilon here is, epsilon = 555.0 * 1e-12.
+    # The following difference is smaller than the epsilon,
+    # thus the prevision and decision will be regarded as equal.
+    decision = prevision * (1 + 1e-15)
+    self.assertNotEqual(prevision, decision)
+    movement.setPrice(decision)
+
+  def stepSetMinimumRangeIntoPriceDivergenceTesterRegardingTestedPropertyToleranceBase(
+        self, sequence):
+    tester = sequence['price_divergence_tester']
+    tester.setProperty('tolerance_base', 'tested_property')
+    # 1 digit smaller than the DEFAULT_PRECISION meaning more strict than default
+    tester.setProperty('tolerance_range_max', 1e-13)
+    tester.setProperty('tolerance_range_min', 1e-13)
+
+  def testFloatDivergenceTesterWithTheDefaultRangeRegardingTestedPropertyToleranceBase(
+        self, quiet=quiet, run=run_all_test):
+    """
+    Test Float Divergence Tester with the default range in a real use-case,
+    in addition, test a tolerance base configurataion: tested_property.
+
+    The defined behavior checking the divergence in FloatEquivalenceTester:
+
+    1. If nothing is configured, the default epsilon range is used
+    2. If not having absolete and having relative, the relative value is used
+    3. If having both absolete and relative value, the absolute value is used
+
+    This test checks case 1 and 2
+    """
+    if not run: return
+    sequence_string = TestPackingListMixin.default_sequence + """
+          SetPackingListMovementAndSimulationMovement
+          ResetDeliveringRule
+          SetNewPrice
+          Tic
+          CheckPackingListIsNotDivergent
+          AddDefaultRangePriceDivergenceTester
+          CheckPackingListIsDivergent
+          SetPreviousPrice
+          Tic
+          CheckPackingListIsNotDivergent
+          SetPreviousPricePlusAValueSmallerThanTheEpsilon
+          Tic
+          CheckPackingListIsNotDivergent
+          SetMinimumRangeIntoPriceDivergenceTesterRegardingTestedPropertyToleranceBase
+          Tic
+          CheckPackingListIsDivergent
+    """
+    sequence = Sequence(self)
+    sequence(sequence_string, quiet=self.quiet)
+
 
 def test_suite():
   suite = unittest.TestSuite()