From 6e14585ca20d27db81f122d2c3a76135e4192fc4 Mon Sep 17 00:00:00 2001
From: mike <michael.durocher@gmail.com>
Date: Tue, 20 Feb 2018 22:51:22 +0100
Subject: [PATCH 1/2] Fix approx default tolerances for Decimal

---
 _pytest/python_api.py     | 16 ++++++++++++++--
 changelog/3247.bugfix.rst |  1 +
 testing/python/approx.py  |  1 +
 3 files changed, 16 insertions(+), 2 deletions(-)
 create mode 100644 changelog/3247.bugfix.rst

diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index 89ef9e0a9..541371449 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -153,6 +153,8 @@ class ApproxScalar(ApproxBase):
     """
     Perform approximate comparisons for single numbers only.
     """
+    DEFAULT_ABSOLUTE_TOLERANCE = 1e-12
+    DEFAULT_RELATIVE_TOLERANCE = 1e-6
 
     def __repr__(self):
         """
@@ -223,7 +225,7 @@ class ApproxScalar(ApproxBase):
 
         # Figure out what the absolute tolerance should be.  ``self.abs`` is
         # either None or a value specified by the user.
-        absolute_tolerance = set_default(self.abs, 1e-12)
+        absolute_tolerance = set_default(self.abs, self.DEFAULT_ABSOLUTE_TOLERANCE)
 
         if absolute_tolerance < 0:
             raise ValueError("absolute tolerance can't be negative: {}".format(absolute_tolerance))
@@ -241,7 +243,7 @@ class ApproxScalar(ApproxBase):
         # we've made sure the user didn't ask for an absolute tolerance only,
         # because we don't want to raise errors about the relative tolerance if
         # we aren't even going to use it.
-        relative_tolerance = set_default(self.rel, 1e-6) * abs(self.expected)
+        relative_tolerance = set_default(self.rel, self.DEFAULT_RELATIVE_TOLERANCE) * abs(self.expected)
 
         if relative_tolerance < 0:
             raise ValueError("relative tolerance can't be negative: {}".format(absolute_tolerance))
@@ -252,6 +254,13 @@ class ApproxScalar(ApproxBase):
         return max(relative_tolerance, absolute_tolerance)
 
 
+class ApproxDecimal(ApproxScalar):
+    from decimal import Decimal
+
+    DEFAULT_ABSOLUTE_TOLERANCE = Decimal('1e-12')
+    DEFAULT_RELATIVE_TOLERANCE = Decimal('1e-6')
+
+
 def approx(expected, rel=None, abs=None, nan_ok=False):
     """
     Assert that two numbers (or two sets of numbers) are equal to each other
@@ -401,6 +410,7 @@ def approx(expected, rel=None, abs=None, nan_ok=False):
 
     from collections import Mapping, Sequence
     from _pytest.compat import STRING_TYPES as String
+    from decimal import Decimal
 
     # Delegate the comparison to a class that knows how to deal with the type
     # of the expected value (e.g. int, float, list, dict, numpy.array, etc).
@@ -422,6 +432,8 @@ def approx(expected, rel=None, abs=None, nan_ok=False):
         cls = ApproxMapping
     elif isinstance(expected, Sequence) and not isinstance(expected, String):
         cls = ApproxSequence
+    elif isinstance(expected, Decimal):
+        cls = ApproxDecimal
     else:
         cls = ApproxScalar
 
diff --git a/changelog/3247.bugfix.rst b/changelog/3247.bugfix.rst
new file mode 100644
index 000000000..e8091f4e5
--- /dev/null
+++ b/changelog/3247.bugfix.rst
@@ -0,0 +1 @@
+Fix issue with approx on Decimal value.
\ No newline at end of file
diff --git a/testing/python/approx.py b/testing/python/approx.py
index 300e1ce86..341e5fcff 100644
--- a/testing/python/approx.py
+++ b/testing/python/approx.py
@@ -249,6 +249,7 @@ class TestApprox(object):
             (Decimal('-1.000001'), Decimal('-1.0')),
         ]
         for a, x in within_1e6:
+            assert a == approx(x)
             assert a == approx(x, rel=Decimal('5e-6'), abs=0)
             assert a != approx(x, rel=Decimal('5e-7'), abs=0)
             assert approx(x, rel=Decimal('5e-6'), abs=0) == a

From 147b43f83216c612ab0122c8a3961895c4222abe Mon Sep 17 00:00:00 2001
From: Bruno Oliveira <nicoddemus@gmail.com>
Date: Wed, 21 Feb 2018 20:31:33 -0300
Subject: [PATCH 2/2] Small changelog tweak

---
 changelog/3247.bugfix.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changelog/3247.bugfix.rst b/changelog/3247.bugfix.rst
index e8091f4e5..9483ceeea 100644
--- a/changelog/3247.bugfix.rst
+++ b/changelog/3247.bugfix.rst
@@ -1 +1 @@
-Fix issue with approx on Decimal value.
\ No newline at end of file
+Fix ``TypeError`` issue when using ``approx`` with a ``Decimal`` value.