make amounts immutable, implement signed amounts

1 files changed, 36 insertions, 38 deletions

diff --git a/tests/test_amount.py b/tests/test_amount.py
index a4043b7..3dd386a 100755
--- a/tests/test_amount.py
+++ b/tests/test_amount.py
@@ -19,53 +19,51 @@
 #  @version 0.0
 #  @repository https://git.taler.net/taler-util.git/
 
-from __future__ import unicode_literals
-from taler.util.amount import Amount, BadFormatAmount, NumberTooBig, NegativeNumber
+from taler.util.amount import Amount, SignedAmount, AmountOverflowError, MAX_AMOUNT_VALUE
 from unittest import TestCase
 import json
-from mock import MagicMock
 
 class TestAmount(TestCase):
-    def setUp(self):
-        self.amount = Amount('TESTKUDOS')
-
     def test_very_big_number(self):
-        with self.assertRaises(NumberTooBig):
+        with self.assertRaises(AmountOverflowError):
             self.Amount = Amount('TESTKUDOS',
-                                 value=99999999999999999999999999999999999999999999)
+                                 value=99999999999999999999999999999999999999999999,
+                                 fraction=0)
 
-    def test_negative_value(self):
-        with self.assertRaises(NegativeNumber):
-            self.Amount = Amount('TESTKUDOS',
-                                 value=-9)
+    def test_add_overflow(self):
+        a1 = Amount('TESTKUDOS',
+                             value=MAX_AMOUNT_VALUE,
+                             fraction=0)
+        with self.assertRaises(AmountOverflowError):
+            a2 = a1 + Amount.parse("TESTKUDOS:1")
+
+    def test_sub_overflow(self):
+        a1 = Amount('TESTKUDOS',
+                             value=MAX_AMOUNT_VALUE,
+                             fraction=0)
+        s1 = SignedAmount(False, a1)
+        with self.assertRaises(AmountOverflowError):
+            s2 = s1 - SignedAmount.parse("TESTKUDOS:1")
 
     def test_parse_and_cmp(self):
-        a = self.amount.parse('TESTKUDOS:0.0')
-        self.assertEqual(Amount.cmp(self.amount, a), 0)
-        b = self.amount.parse('TESTKUDOS:0.1')
-        self.assertEqual(Amount.cmp(Amount('TESTKUDOS', fraction=10000000), b), 0)
-        c = self.amount.parse('TESTKUDOS:3.3')
-        self.assertEqual(Amount.cmp(Amount('TESTKUDOS', 3, 30000000), c), 0)
-        self.assertEqual(Amount.cmp(a, b), -1)
-        self.assertEqual(Amount.cmp(c, b), 1)
-        with self.assertRaises(BadFormatAmount):
-            Amount.parse(':3')
+        self.assertTrue(Amount.parse("EUR:0.0") < Amount.parse("EUR:0.5"))
+
+    def test_amount(self):
+        self.assertEqual(Amount.parse("TESTKUDOS:0").stringify(3), "TESTKUDOS:0.000")
+
+    def test_signed_amount(self):
+        self.assertEqual(SignedAmount.parse("TESTKUDOS:1.5").stringify(3), "+TESTKUDOS:1.500")
+
+    def test_zero_crossing(self):
+        p1 = SignedAmount.parse("EUR:1")
+        p2 = SignedAmount.parse("EUR:2")
+        p3 = SignedAmount.parse("EUR:3")
+        p5 = SignedAmount.parse("EUR:5")
+        p8 = SignedAmount.parse("EUR:8")
 
-    def test_add_and_dump(self):
-        mocky = MagicMock()
-        self.amount.add(Amount('TESTKUDOS', 9, 10**8))
-        mocky(**self.amount.dump())
-        mocky.assert_called_with(currency='TESTKUDOS', value=10, fraction=0)
+        self.assertEqual(p5 + p3, p8)
+        self.assertEqual(p5 - p3, p2)
+        self.assertEqual(p2 - p3, -p1)
 
-    def test_subtraction(self):
-        with self.assertRaises(ValueError):
-            self.amount.subtract(Amount('TESTKUDOS', fraction=1))
-        a = Amount('TESTKUDOS', 2)
-        a.subtract(Amount('TESTKUDOS', 1, 99999999))
-        self.assertEqual(Amount.cmp(a, Amount('TESTKUDOS', fraction=1)), 0)
+        self.assertEqual((-p2) + p3, p1)
 
-    def test_stringify(self):
-        self.assertEqual(self.amount.stringify(3), 'TESTKUDOS:0.000')
-        self.amount.add(Amount('TESTKUDOS', 2, 100))
-        self.assertEqual(self.amount.stringify(6), 'TESTKUDOS:2.000001')
-        self.assertEqual(Amount("TESTKUDOS", value=5, fraction=9000000).stringify(), 'TESTKUDOS:5.09')