From 0581525c98241a78104097f75f80ed29e6623784 Mon Sep 17 00:00:00 2001
From: Brett Smith <brettcsmith@brettcsmith.org>
Date: Sat, 6 Jun 2020 11:31:04 -0400
Subject: [PATCH] reports: Add Balance.__pos__() method.

I did this while I was working on normalize_amount_func.
It turns out it's not immediately needed, but it's still nice to have.
---
 conservancy_beancount/reports/core.py |  3 +++
 tests/test_reports_balance.py         | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/conservancy_beancount/reports/core.py b/conservancy_beancount/reports/core.py
index 01e04cd..9c0ae79 100644
--- a/conservancy_beancount/reports/core.py
+++ b/conservancy_beancount/reports/core.py
@@ -140,6 +140,9 @@ class Balance(Mapping[str, data.Amount]):
     def __neg__(self: BalanceType) -> BalanceType:
         return type(self)(-amt for amt in self.values())
 
+    def __pos__(self: BalanceType) -> BalanceType:
+        return self
+
     def __getitem__(self, key: str) -> data.Amount:
         return self._currency_map[key]
 
diff --git a/tests/test_reports_balance.py b/tests/test_reports_balance.py
index 93a918f..3a424b4 100644
--- a/tests/test_reports_balance.py
+++ b/tests/test_reports_balance.py
@@ -168,6 +168,20 @@ def test_neg(mapping):
     for key, number in mapping.items():
         assert actual[key] == testutil.Amount(-number, key)
 
+@pytest.mark.parametrize('mapping', [
+    {},
+    {'USD': 0},
+    {'EUR': 10},
+    {'JPY': 20, 'BRL': 30},
+    {'EUR': -15},
+    {'JPY': -25, 'BRL': -35},
+    {'JPY': 40, 'USD': 0, 'EUR': -50},
+])
+def test_pos(mapping):
+    amounts = frozenset(amounts_from_map(mapping))
+    actual = +core.Balance(amounts)
+    assert set(actual.values()) == amounts
+
 @pytest.mark.parametrize('map1,map2,expected', [
     ({}, {}, True),
     ({}, {'USD': 0}, True),