From: Ismaël Bouya <ismael.bouya@normalesup.org>
Date: Mon, 12 Feb 2018 01:13:17 +0000 (+0100)
Subject: Add missing amount operations
X-Git-Tag: v0.1~9
X-Git-Url: https://git.immae.eu/?a=commitdiff_plain;h=f320eb8aafbceafbbfca02617db4846b3571e598;hp=0c79fad318711394874d94672e96db6da1ed9c52;p=perso%2FImmae%2FProjets%2FCryptomonnaies%2FCryptoportfolio%2FTrader.git

Add missing amount operations
---

diff --git a/portfolio.py b/portfolio.py
index 17a17ba..21a9834 100644
--- a/portfolio.py
+++ b/portfolio.py
@@ -124,6 +124,8 @@ class Amount:
         return Amount(self.currency, abs(self.value))
 
     def __add__(self, other):
+        if other == 0:
+            return self
         if other.currency != self.currency and other.value * self.value != 0:
             raise Exception("Summing amounts must be done with same currencies")
         return Amount(self.currency, self.value + other.value)
@@ -141,6 +143,12 @@ class Amount:
             raise Exception("Summing amounts must be done with same currencies")
         return Amount(self.currency, self.value - other.value)
 
+    def __rsub__(self, other):
+        if other == 0:
+            return -self
+        else:
+            return -self.__sub__(other)
+
     def __mul__(self, value):
         if not isinstance(value, (int, float, D)):
             raise TypeError("Amount may only be multiplied by numbers")
diff --git a/test.py b/test.py
index 1965521..c496e11 100644
--- a/test.py
+++ b/test.py
@@ -220,6 +220,8 @@ class AmountTest(WebMockTestCase):
         amount4 = portfolio.Amount("ETH", 0.0)
         self.assertEqual(amount1, amount1 + amount4)
 
+        self.assertEqual(amount1, amount1 + 0)
+
     def test__radd(self):
         amount = portfolio.Amount("XVG", "12.9")
 
@@ -241,6 +243,13 @@ class AmountTest(WebMockTestCase):
         amount4 = portfolio.Amount("ETH", 0.0)
         self.assertEqual(amount1, amount1 - amount4)
 
+    def test__rsub(self):
+        amount = portfolio.Amount("ETH", "1.6")
+        with self.assertRaises(Exception):
+            3 - amount
+
+        self.assertEqual(portfolio.Amount("ETH", "-1.6"), -amount)
+
     def test__mul(self):
         amount = portfolio.Amount("XEM", 11)