BDD / TDD assertion library for Python
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In order to use robber, you need to import expect from the
module:
.. code:: python
from robber import expect
That's all. You are good to go.
Assertions ~~~~~~~~~~
eq/== ^^^^^
Asserts that actual is equal (==) to expected:
.. code:: python
expect(1).to.eq(1)
expect([1, 2]).to.eq([1, 2])
Also:
.. code:: python
expect(1) == 1
ne/!= ^^^^^
Asserts that actual is not equal (!=) to expected:
.. code:: python
expect(1).to.ne(2)
expect(1).to != 2
expect(1) != 2
equal ^^^^^
Asserts that the target is identical (is) to the expected:
.. code:: python
expect(1).to.equal(1)
true ^^^^
Asserts that the target is True:
.. code:: python
expect(True).to.be.true()
false ^^^^^
Asserts that the target is False:
.. code:: python
expect(False).to.be.false()
instanceof ^^^^^^^^^^
Asserts that the target is an instance of expected:
.. code:: python
expect(obj).to.be.instanceof(Klass)
match ^^^^^
Asserts that the target can be matched by a regular expression:
.. code:: python
expect('foo').to.match(r'foo')
respond_to ^^^^^^^^^^^
Asserts that the target responds to a method:
.. code:: python
expect(obj).to.respond_to('method')
truthy ^^^^^^
Asserts that the target is truthy:
.. code:: python
expect(['test']).to.be.truthy()
falsy ^^^^^
Asserts that the target is falsy:
.. code:: python
expect([]).to.be.falsy()
length ^^^^^^
Asserts that the target has a length of expected:
.. code:: python
expect([1, 2]).to.have.length(2)
expect('str').to.have.length(3)
empty ^^^^^
Asserts that the target is empty:
.. code:: python
expect([]).to.be.empty()
expect('').to.be.empty()
string ^^^^^^
Asserts that the target is a string:
.. code:: python
expect('str').to.be.a.string()
integer ^^^^^^^
Asserts that the target is an integer:
.. code:: python
expect('str').to.be.an.integer()
float ^^^^^
Asserts that the target is floating point number:
.. code:: python
expect(1.0).to.be.a.float()
list ^^^^
Asserts that the target is a list:
.. code:: python
expect([1, 2]).to.be.a.list()
dict ^^^^
Asserts that the target is a dictionary:
.. code:: python
expect({}).to.be.a.dict()
tuple ^^^^^
Asserts that the target is a tuple:
.. code:: python
expect((1, 2)).to.be.a.tuple()
none ^^^^
Asserts that the target is None:
.. code:: python
expect(None).to.be.none()
above ^^^^^
Asserts that the target is above expected:
.. code:: python
expect(2).to.be.above(1)
below ^^^^^
Asserts that the target is below expected:
.. code:: python
expect(1).to.be.below(2)
within ^^^^^^
Asserts that the target is within expected:
.. code:: python
expect(2).to.be.within(0, 2)
contain ^^^^^^^
Asserts that the target contains an element, or a key:
.. code:: python
expect([1,2,3]).to.contain(1, 2, 3)
expect({'foo': 'bar', 'foo1': 'bar1'}).to.contain('foo', 'foo1')
exclude ^^^^^^^
Asserts that the target does not contain an element, or a key:
.. code:: python
expect({'foo': 'bar'}).to.exclude('baz')
throw ^^^^^
Asserts that the target throws an exception (or its subclass)
.. code:: python
expect(lambda: raise_exception(...)).to.throw(Exception)
expect(lambda: raise_exception(...)).to.throw(ParentException)
expect(any_callable).to.throw(Exception)
expect(any_callable).to.throw(ParentException)
throw_exactly ^^^^^^^^^^^^^^
Asserts that the target throws exactly an exception (not its subclass)
.. code:: python
expect(lambda: raise_exception(...)).to.throw_exactly(Exception)
expect(any_callable).to.throw_exactly(Exception)
called ^^^^^^
Asserts that a mock has been called
.. code:: python
expect(mock).to.be.called()
called_once ^^^^^^^^^^^^
Asserts that a mock has been called exactly one time
.. code:: python
expect(mock).to.be.called_once()
callable ^^^^^^^^
Asserts that a object is callable
.. code:: python
expect(object).to.be.callable()
called_with ^^^^^^^^^^^^
Asserts that a mock has been called with params
.. code:: python
expect(mock).to.be.called_with(*args, **kwargs)
called_once_with ^^^^^^^^^^^^^^^^^^
Asserts that a mock has been called once with params
.. code:: python
expect(mock).to.be.called_once_with(*args, **kwargs)
ever_called_with ^^^^^^^^^^^^^^^^^^
Asserts that a mock has ever been called with params. The call is not necessary to be to latest one (the same as assert.any_call).
.. code:: python
expect(mock).to.have.been.ever_called_with(*args, **kwargs)
expect(mock).to.have.any_call(*args, **kwargs)
Language chains ~~~~~~~~~~~~~~~
In order to write more readable assertions, there are a few built-in language chains that you can use:
Positive chains ^^^^^^^^^^^^^^^
Negative chains ^^^^^^^^^^^^^^^
For example, the following two lines are functionally equivalent:
.. code:: python
expect(1.0).to.be.a.float()
expect(1.0).float()
Expectation chaining ~~~~~~~~~~~~~~~~~~~~
In the spirit of more readable assertions, and to eliminate redundant evaluations of the same expression, you can chain multiple expectations.
For example, the following two lines are functionally equivalent. The first example evaluates the expression '1 + 1' only once:
.. code:: python
expect(1 + 1).to.be.an.integer().to.be.within(1, 3)
expect(1 + 1).to.be.an.integer()
expect(1 + 1).to.be within(1, 3)
Custom assertions ~~~~~~~~~~~~~~~~~
Writing custom assertion is as easy as extending a base matcher class
and adding the method matches for matching and the property
explanation for the error notice:
.. code:: python
class Chain(Base):
def matches(self):
expectation = self.actual(None)
chain = getattr(expectation, self.expected)
return expectation is chain
@property
def explanation(self):
return Explanation(self.actual, self.is_negative, 'have chain', self.expected)
expect.register('chain', Chain)
After you register the new matcher, you can use it as expected:
.. code:: python
expect(obj).to.have.chain('be')
Custom error messages ~~~~~~~~~~~~~~~~~~~~~
If you want to have custom explanations, for assertion or group of assertions, you can simply do:
.. code:: python
from robber import CustomExplanation
with CustomExplanation('Something went wrong'):
expect(1).to.eq(2)
.. code:: bash
$ pip install robber
.. code:: bash
$ nosetests tests/
MIT License
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