def test_exposeDocAttribute(self):
"""
Creating an exposer should require a docstring explaining what it's
for.
"""
docstring = "This is my docstring."
exposer = Exposer(docstring)
self.assertEqual(exposer.__doc__, docstring)
def setUp(self):
"""
Create two exposers to expose methods in tests.
"""
self.exposer = Exposer("test exposer")
self.otherExposer = Exposer("other exposer")
class ExposeTests:
"""
This mixin provides tests for expose, based on a parameterized base type
for the class which methods are being exposed on. Subclass this before
L{TestCase} and set L{superClass} to use this.
@ivar superClass: the class to be subclassed by all classes which expose
methods.
"""
superClass = None
def setUp(self):
"""
Create two exposers to expose methods in tests.
"""
self.exposer = Exposer("test exposer")
self.otherExposer = Exposer("other exposer")
def test_exposeDocAttribute(self):
"""
Creating an exposer should require a docstring explaining what it's
for.
"""
docstring = "This is my docstring."
exposer = Exposer(docstring)
self.assertEqual(exposer.__doc__, docstring)
def test_simpleExpose(self):
"""
Creating an exposer, defining a class and exposing a method of a class
with that exposer, then retrieving a method of that class should result
in the method of that class.
"""
class Foo(self.superClass):
def __init__(self, num):
self.num = num
@self.exposer.expose()
def bar(self):
return self.num + 1
f = Foo(3)
method = self.exposer.get(f, 'bar')
self.assertEqual(method(), 4)
def test_notExposed(self):
"""
Creating an exposer and then attempting to retrieve a method not
exposed with it should result in a L{MethodNotExposed} exception.
"""
class Foo(self.superClass):
def bar(self):
return 1
f = Foo()
self.assertRaises(MethodNotExposed, self.exposer.get, f, 'bar')
def test_differentMethodsDifferentExposers(self):
"""
Methods should only be able to be retrieved with the exposer that
exposed them, not with any other exposer.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 1
@self.otherExposer.expose()
def baz(self):
return 2
f = Foo()
self.assertEqual(self.exposer.get(f, 'bar')(), 1)
self.assertEqual(self.otherExposer.get(f, 'baz')(), 2)
self.assertRaises(MethodNotExposed, self.otherExposer.get, f, 'bar')
self.assertRaises(MethodNotExposed, self.exposer.get, f, 'baz')
def test_sameMethodExposedByDifferentExposers(self):
"""
If the same method is exposed by two different exposers, it should be
accessible by both of them.
"""
class Foo(self.superClass):
@self.exposer.expose()
@self.otherExposer.expose()
def bar(self):
return 4
f = Foo()
self.assertEqual(self.exposer.get(f, 'bar')(), 4)
self.assertEqual(self.otherExposer.get(f, 'bar')(), 4)
def test_exposeWithDifferentKey(self):
"""
The 'key' argument to {Exposer.expose} should change the argument to
'get'.
"""
class Foo(self.superClass):
@self.exposer.expose(key='hello')
def bar(self):
return 7
f = Foo()
self.assertEqual(self.exposer.get(f, 'hello')(), 7)
def test_exposeOnDifferentClass(self):
"""
An exposer should only be able to retrieve a method from instances of
types which it has explicitly exposed methods on. Instances of
different types with the same method name should raise
L{MethodNotExposed}.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 7
class Baz(self.superClass):
def bar(self):
return 8
f = Foo()
b = Baz()
self.assertEqual(self.exposer.get(f, 'bar')(), 7)
self.assertRaises(MethodNotExposed, self.otherExposer.get, b, 'bar')
def test_exposeUnnamedNoKey(self):
"""
L{Exposer.expose} raises L{NameRequired} when called without a value
for the C{key} parameter if it is used to decorate a non-function
object.
"""
def f():
class Foo(self.superClass):
@self.exposer.expose()
@classmethod
def foo(self):
pass
self.assertRaises(NameRequired, f)
def test_exposeNonMethod(self):
"""
L{Exposer.expose} should work on methods which have been decorated by
another decorator and will therefore not result in function objects
when retrieved with __get__.
"""
class Getter(record('function')):
def __get__(self, oself, type):
return self.function
class Foo(self.superClass):
@self.exposer.expose(key='bar')
@Getter
def bar():
return 7
f = Foo()
# Sanity check
self.assertEqual(f.bar(), 7)
self.assertEqual(self.exposer.get(f, 'bar')(), 7)
def test_descriptorGetsType(self):
"""
L{Exposer.get} should not interfere with the appropriate type object
being passed to the wrapped descriptor's C{__get__}.
"""
types = []
class Getter(record('function')):
def __get__(self, oself, type):
types.append(type)
return self.function
class Foo(self.superClass):
@self.exposer.expose(key='bar')
@Getter
def bar():
return 7
f = Foo()
self.exposer.get(f, 'bar')
self.assertEqual(types, [Foo])
def test_descriptorGetsSubtype(self):
"""
When a descriptor is exposed through a superclass, getting it from a
subclass results in the subclass being passed to the C{__get__} method.
"""
types = []
class Getter(record('function')):
def __get__(self, oself, type):
types.append(type)
return self.function
class Foo(self.superClass):
@self.exposer.expose(key='bar')
@Getter
def bar():
return 7
class Baz(Foo):
pass
b = Baz()
self.exposer.get(b, 'bar')
self.assertEqual(types, [Baz])
def test_implicitSubclassExpose(self):
"""
L{Exposer.expose} should expose the given object on all subclasses.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 7
class Baz(Foo):
pass
b = Baz()
self.assertEqual(self.exposer.get(b, 'bar')(), 7)
def test_overrideDontExpose(self):
"""
L{Exposer.expose} should not expose overridden methods on subclasses.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 7
class Baz(Foo):
def bar(self):
return 8
b = Baz()
self.assertRaises(MethodNotExposed, self.otherExposer.get, b, 'bar')
def test_sameKeyOnDifferentTypes(self):
"""
L{Exposer.expose} should work with the same key on different types.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 17
class Qux(self.superClass):
@self.exposer.expose()
def bar(self):
return 71
q = Qux()
f = Foo()
self.assertEqual(self.exposer.get(q, 'bar')(), 71)
self.assertEqual(self.exposer.get(f, 'bar')(), 17)
def test_overrideReExpose(self):
"""
L{Exposer.expose} should expose a method on a subclass if that method
is overridden.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 7
class Baz(Foo):
@self.exposer.expose()
def bar(self):
return 8
f = Foo()
b = Baz()
self.assertEqual(self.exposer.get(f, 'bar')(), 7)
self.assertEqual(self.exposer.get(b, 'bar')(), 8)
def test_deleteExposedAttribute(self):
"""
When an exposed attribute is deleted from a class, it should no longer
be exposed; calling L{Exposer.get} should result in
L{MethodNotExposed}.
"""
class Foo(self.superClass):
@self.exposer.expose()
def bar(self):
return 7
f = Foo()
del Foo.bar
self.assertRaises(MethodNotExposed, self.otherExposer.get, f, 'bar')
