STY: Update and pin black version.

Author: ssanderson

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 default_language_version:
-  python: python3.6
+  python: python3.7
 
 repos:
 
@@ -23,8 +23,8 @@ repos:
     hooks:
       - id: isort
 
-  - repo: https://github.com/ambv/black
-    rev: stable
+  - repo: https://github.com/psf/black
+    rev: 20.8b1
     hooks:
     - id: black
-      language_version: python3.6
+      language_version: python3.7

interface/default.py

@@ -7,8 +7,7 @@
 
 
 class default(object):
-    """Default implementation of a function in terms of interface methods.
-    """
+    """Default implementation of a function in terms of interface methods."""
 
     def __init__(self, implementation):
         self.implementation = implementation
@@ -32,8 +31,7 @@ class UnsafeDefault(UserWarning):
     )
 
     def warn_if_defaults_use_non_interface_members(interface_name, defaults, members):
-        """Warn if an interface default uses non-interface members of self.
-        """
+        """Warn if an interface default uses non-interface members of self."""
         for method_name, attrs in non_member_attributes(defaults, members):
             warnings.warn(
                 _DEFAULT_USES_NON_INTERFACE_MEMBER_TEMPLATE.format(

interface/interface.py

@@ -81,7 +81,8 @@ def _conflicting_defaults(typename, conflicts):
             The following interfaces provided default implementations for {attr!r}:
             {interfaces}"""
         ).format(
-            attr=attrname, interfaces=bulleted_list(sorted(map(getname, interfaces))),
+            attr=attrname,
+            interfaces=bulleted_list(sorted(map(getname, interfaces))),
         )
     return InvalidImplementation(message)
 
@@ -116,7 +117,9 @@ def __new__(mcls, name, bases, clsdict):
                 errmsg = (
                     "Couldn't parse signature for field "
                     "{iface_name}.{fieldname} of type {attrtype}.".format(
-                        iface_name=name, fieldname=field, attrtype=getname(type(v)),
+                        iface_name=name,
+                        fieldname=field,
+                        attrtype=getname(type(v)),
                     )
                 )
                 raise_from(TypeError(errmsg), e)
@@ -131,7 +134,10 @@ def __new__(mcls, name, bases, clsdict):
                     "\nInterface field {new}.{field} conflicts with inherited field of "
                     "the same name.\n"
                     "  - {field}{new_sig} != {field}{old_sig}".format(
-                        new=name, field=field, new_sig=signature, old_sig=conflicted,
+                        new=name,
+                        field=field,
+                        new_sig=signature,
+                        old_sig=conflicted,
                     )
                 )
             else:
@@ -228,7 +234,8 @@ def _invalid_implementation(self, t, missing, mistyped, mismatched):
         assert missing or mistyped or mismatched, "Implementation wasn't invalid."
 
         message = "\nclass {C} failed to implement interface {I}:".format(
-            C=getname(t), I=getname(self),
+            C=getname(t),
+            I=getname(self),
         )
         if missing:
             message += dedent(
@@ -293,7 +300,9 @@ def _format_mismatched_methods(self, mismatched):
             sorted(
                 [
                     "  - {name}{actual} != {name}{expected}".format(
-                        name=name, actual=bad_sig, expected=self._signatures[name],
+                        name=name,
+                        actual=bad_sig,
+                        expected=self._signatures[name],
                     )
                     for name, bad_sig in mismatched.items()
                 ]
@@ -470,7 +479,9 @@ def format_iface_method_docs(I):
     return "\n".join(
         [
             "{iface_name}.{method_name}{sig}".format(
-                iface_name=iface_name, method_name=method_name, sig=sig,
+                iface_name=iface_name,
+                method_name=method_name,
+                sig=sig,
             )
             for method_name, sig in sorted(list(I._signatures.items()), key=first)
         ]
@@ -564,7 +575,10 @@ def method2(self, y):
         )
 
         result = ImplementsMeta(
-            name, (object,), {"__doc__": doc}, interfaces=interfaces,
+            name,
+            (object,),
+            {"__doc__": doc},
+            interfaces=interfaces,
         )
 
         # NOTE: It's important for correct weak-memoization that this is set is

interface/tests/test_interface.py

@@ -903,6 +903,7 @@ def method_b(self):
 
     # expected to fail since it's missing method_b
     with pytest.raises(InvalidImplementation) as exc:
+
         class JustA(implements(AandB)):  # pragma: nocover
             def method_a(self):
                 pass
@@ -919,6 +920,7 @@ class JustA failed to implement interface AandB:
 
     # expected to fail since it's missing method_a
     with pytest.raises(InvalidImplementation) as exc:
+
         class JustB(implements(AandB)):  # pragma: nocover
             def method_b(self):
                 pass
@@ -958,6 +960,7 @@ def method_b(self):
 
     # expected to fail since method_a has different signature in interface A
     with pytest.raises(TypeError) as exc:
+
         class C1(A):  # pragma: nocover
             def method_a(self, x):
                 pass
@@ -972,6 +975,7 @@ def method_a(self, x):
 
     # expected to fail since method_b has different signature in interface B
     with pytest.raises(TypeError) as exc:
+
         class C2(B):  # pragma: nocover
             def method_b(self, y, z=None):
                 pass

interface/typed_signature.py

@@ -47,7 +47,8 @@ def __str__(self):
 
     def __repr__(self):
         return "<TypedSignature type={}, signature={}>".format(
-            self._type.__name__, self._signature,
+            self._type.__name__,
+            self._signature,
         )