.. _API Reference: API Reference ============= Setup/Teardown -------------- You might be familiar with to how the :py:mod:`unittest` module suggests to `implement setup and teardown callbacks `_ for your tests. But if you prefer to define test cases as functions and use a runner like `nose `_ then *sure* can help you define and activate modular fixtures. In *sure's* parlance, we call it a *Scenario* Example: Setup a Flask app for testing ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``my_flask_app.py`` ................... .. code:: import json from flask import Response, Flask webapp = Flask(__name__) @webapp.route('/') def index(): data = json.dumps({'hello': 'world'}} return Response(data, headers={'Content-Type': 'application/json'}) ``tests/scenarios.py`` ...................... .. code:: python from sure import scenario from my_flask_app import webapp def prepare_webapp(context): context.server = webapp.test_client() web_scenario = scenario(prepare_webapp) ``tests/test_webapp.py`` ........................ .. code:: python import json from sure import scenario from tests.scenarios import web_scenario @web_scenario def test_hello_world(context): # Given that I GET / response = context.server.get('/') # Then it should have returned a successful json response response.headers.should.have.key('Content-Type').being.equal('application/json') response.status_code.should.equal(200) json.loads(response.data).should.equal({'hello': 'world'}) Example: Multiple Setup and Teardown functions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``tests/scenarios.py`` ...................... .. code:: python import os import shutil from sure import scenario def prepare_directories(context): context.root = os.path.dirname(os.path.abspath(__file__)) context.fixture_path = os.path.join(context.root, 'input_data') context.result_path = os.path.join(context.root, 'output_data') context.directories = [ context.fixture_path, context.result_path, ] for path in context.directories: if os.path.isdir(path): shutil.rmtree(path) os.makedirs(path) def cleanup_directories(context): for path in context.directories: if os.path.isdir(path): shutil.rmtree(path) def create_10_dummy_hex_files(context): for index in range(10): filename = os.path.join(context.fixture_path, 'dummy-{}.hex'.format(index)) open(filename, 'wb').write(os.urandom(32).encode('hex')) dummy_files_scenario = scenario([create_directories, create_10_dummy_hex_files], [cleanup_directories]) ``tests/test_filesystem.py`` ........................ .. code:: python import os from tests.scenarios import dummy_files_scenario @dummy_files_scenario def test_files_exist(context): os.listdir(context.fixture_path).should.equal([ 'dummy-0.hex', 'dummy-1.hex', 'dummy-2.hex', 'dummy-3.hex', 'dummy-4.hex', 'dummy-5.hex', 'dummy-6.hex', 'dummy-7.hex', 'dummy-8.hex', 'dummy-9.hex', ]) Number Equality --------------- ``(2 + 2).should.equal(4)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python import sure (4).should.be.equal(2 + 2) (7.5).should.eql(3.5 + 4) (2).should.equal(8 / 4) (3).shouldnt.be.equal(5) ``.equal(float, epsilon)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python import sure (4.242423).should.be.equal(4.242420, epsilon=0.000005) (4.01).should.be.eql(4.00, epsilon=0.01) (6.3699999).should.equal(6.37, epsilon=0.001) (4.242423).shouldnt.be.equal(4.249000, epsilon=0.000005) String Equality --------------- ``.should_not.be.different_of(string)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python import sure XML1 = ''' AND A VALUE ''' XML1.should_not.be.different_of(XML1) XML2 = ''' AND A VALUE ''' XML2.should.be.different_of(XML1) this will give you and output like .. code:: bash Difference: - AND A VALUE ? -- + AND A VALUE ? ++ ''' ``.should.equal("a string")`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python "Awesome ASSERTIONS".lower().split().should.equal(['awesome', 'assertions']) String Similarity ----------------- ``.look_like()`` ~~~~~~~~~~~~~~~~ .. code:: python """ THIS IS MY loose string """.should.look_like('this is my loose string') """this one is different""".should_not.look_like('this is my loose string') Strings Matching Regular-Expressions ------------------------------------ ``should.match()`` ~~~~~~~~~~~~~~~~~~ You can also use the modifiers: - `re.DEBUG `__ - `re.I and re.IGNORECASE `_ - `re.M and re.MULTILINE `_ - `re.S re.DOTALL `_ - `re.U and re.UNICODE `_ - `re.X and re.VERBOSE `_ .. code:: python import re "SOME STRING".should.match(r'some \w+', re.I) "FOO BAR CHUCK NORRIS".should_not.match(r'some \w+', re.M) Collections and Iterables ------------------------- Works with: - Lists, Tuples, Sets - Dicts, OrderedDicts - Anything that implements ``__iter__()`` / ``next()`` ``.equal({'a': 'collection'})`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python {'foo': 'bar'}.should.equal({'foo': 'bar'}) {'foo': 'bar'}.should.eql({'foo': 'bar'}) {'foo': 'bar'}.must.be.equal({'foo': 'bar'}) ``.contain()`` ~~~~~~~~~~~~~~~~~~~~~ ``expect(collection).to.contain(item)`` is a shorthand to ``expect(item).to.be.within(collection)`` .. code:: python ['1.2.5', '1.2.4'].should.contain('1.2.5') '1.2.4'].should.be.within(['1.2.5', '1.2.4']) # also works with strings "My bucket of text".should.contain('bucket') "life".should_not.contain('anger') '1.2.3'.should.contain('2') ``.should.be.empty`` ~~~~~~~~~~~~~~~~~~~~ .. code:: python [].should.be.empty; {}.should.be.empty; set().should.be.empty; "".should.be.empty; ().should.be.empty range(0).should.be.empty; ## negate with: [1, 2, 3].shouldnt.be.empty; "Dummy String".shouldnt.be.empty; "Dummy String".should_not.be.empty; ``{number}.should.be.within(0, 10)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ asserts inclusive numeric range .. code:: python (1).should.be.within(0, 2) (5).should.be.within(0, 10) ## negate with: (1).shouldnt.be.within(5, 6) ``.be.within({iterable})`` ~~~~~~~~~~~~~~~~~~~~~~~~~~ asserts that a member is part of the iterable .. code:: python "g".should.be.within("gabriel") 'name'.should.be.within({'name': 'Gabriel'}) 'Lincoln'.should.be.within(['Lincoln', 'Gabriel']) ## negate with: 'Bug'.shouldnt.be.within(['Sure 1.0']) 'Bug'.should_not.be.within(['Sure 1.0']) ``.be.none`` ~~~~~~~~~~~~ Assert whether an object is or not ``None`` .. code:: python value = None value.should.be.none None.should.be.none "".should_not.be.none (not None).should_not.be.none ``.be.ok`` ~~~~~~~~~~ Assert truthfulness: .. code:: python from sure import this True.should.be.ok 'truthy string'.should.be.ok {'truthy': 'dictionary'}.should.be.ok And negate truthfulness: .. code:: python from sure import this False.shouldnt.be.ok ''.should_not.be.ok {}.shouldnot.be.ok ``.have.property()`` ~~~~~~~~~~~~~~~~~~~~ .. code:: python class Basket(object): fruits = ["apple", "banana"] basket1 = Basket() basket1.should.have.property("fruits") ``.have.property().being.*`` ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If the programmer calls ``have.property()`` it returns an assertion builder of the property if it exists, so that you can chain up assertions for the property value itself. .. code:: python class Basket(object): fruits = ["apple", "banana"] basket2 = Basket() basket2.should.have.property("fruits").which.should.be.equal(["apple", "banana"]) basket2.should.have.property("fruits").being.equal(["apple", "banana"]) basket2.should.have.property("fruits").with_value.equal(["apple", "banana"]) basket2.should.have.property("fruits").with_value.being.equal(["apple", "banana"]) ``.have.key()`` ~~~~~~~~~~~~~~~ .. code:: python basket3 = dict(fruits=["apple", "banana"]) basket3.should.have.key("fruits") ``.have.key().being.*`` ^^^^^^^^^^^^^^^^^^^^^^^ If the programmer calls ``have.key()`` it returns an assertion builder of the key if it exists, so that you can chain up assertions for the dictionary key value itself. .. code:: python person = dict(name=None) person.should.have.key("name").being.none person.should.have.key("name").being.equal(None) ``.have.length_of(2)`` ~~~~~~~~~~~~~~~~~~~~~~ Assert the length of objects .. code:: python [3, 4].should.have.length_of(2) "Python".should.have.length_of(6) {'john': 'person'}.should_not.have.length_of(2) ``{X}.should.be.greater_than(Y) and {Y}.should.be.lower_than(X)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Assert the magnitude of objects with ``{X}.should.be.greater_than(Y)`` and ``{Y}.should.be.lower_than(X)`` as well as ``{X}.should.be.greater_than_or_equal_to(Y)`` and ``{Y}.should.be.lower_than_or_equal_to(X)``. .. code:: python (5).should.be.greater_than(4) (5).should_not.be.greater_than(10) (1).should.be.lower_than(2) (1).should_not.be.lower_than(0) (5).should.be.greater_than_or_equal_to(4) (5).should_not.be.greater_than_or_equal_to(10) (1).should.be.lower_than_or_equal_to(2) (1).should_not.be.lower_than_or_equal_to(0) Callables --------- ``callable.when.called_with(arg1, kwarg1=2).should.have.raised(Exception)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can use this feature to assert that a callable raises an exception: .. code:: python range.when.called_with("chuck norris").should.have.raised(TypeError) range.when.called_with(10).should_not.throw(TypeError) Regular Expression matching on the exception message ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ You can also match regular expressions with to the expected exception messages: .. code:: python import re range.when.called_with(10, step=20).should.have.raised(TypeError, re.compile(r'(does not take|takes no) keyword arguments')) range.when.called_with("chuck norris").should.have.raised(TypeError, re.compile(r'(cannot be interpreted as an integer|integer end argument expected)')) ``.should.throw(Exception)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An idiomatic alias to ``.should.have.raised``. .. code:: python range.when.called_with(10, step="20").should.throw(TypeError, "range() takes no keyword arguments") range.when.called_with(b"chuck norris").should.throw("range() integer end argument expected, got str.") ``function.when.called_with(arg1, kwarg1=2).should.return_value(value)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is a shorthand for testing that a callable returns the expected result .. code:: python list.when.called_with([0, 1]).should.have.returned_the_value([0, 1]) which equates to: :: value = range(2) value.should.equal([0, 1]) there are no differences between those 2 possibilities, use at will ``.be.a('typename')`` ~~~~~~~~~~~~~~~~~~~~~ this takes a type name and checks if the class matches that name .. code:: python import sure {}.should.be.a('dict') (5).should.be.an('int') ## also works with paths to modules range(10).should.be.a('collections.Iterable') ``.be.a(type)`` ~~~~~~~~~~~~~~~~~~~~~~ this takes the class (type) itself and checks if the object is an instance of it .. code:: python import sure from six import PY3 if PY3: u"".should.be.an(str) else: u"".should.be.an(unicode) [].should.be.a(list) ``.be.above(num) and .be.below(num)`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ assert the instance value above and below ``num`` .. code:: python import sure (10).should.be.below(11) (10).should.be.above(9) (10).should_not.be.above(11) (10).should_not.be.below(9) ``it()``, ``this()``, ``those()``, ``these()`` ---------------------------------------------- ``.should`` aliases to make your tests more idiomatic. Whether you don't like the ``object.should`` syntax or you are simply not running CPython, sure still allows you to use any of the assertions above, all you need to do is wrap the object that is being compared in one of the following options: ``it``, ``this``, ``those`` and ``these``. Too long, don't read ~~~~~~~~~~~~~~~~~~~~ All those possibilities below work just as the same ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ .. code:: python from sure import it, this, those, these (10).should.be.equal(5 + 5) this(10).should.be.equal(5 + 5) it(10).should.be.equal(5 + 5) these(10).should.be.equal(5 + 5) those(10).should.be.equal(5 + 5) Also if you prefer using the assert keyword in your tests just go ahead an do it! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Every assertion returns ``True`` when succeeded, and if failed the AssertionError is already raised internally by sure, with a nice description of what failed to match, too. .. code:: python from sure import it, this, those, these, expect assert (10).should.be.equal(5 + 5) assert this(10).should.be.equal(5 + 5) assert it(10).should.be.equal(5 + 5) assert these(10).should.be.equal(5 + 5) assert those(10).should.be.equal(5 + 5) expect(10).to.be.equal(5 + 5) expect(10).to.not_be.equal(8) ``(lambda: None).should.be.callable`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Test if something is or not callable .. code:: python import sure range.should.be.callable (lambda: None).should.be.callable; (123).should_not.be.callable A note about the assert keyword ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ .. note:: *you can use or not the* ``assert`` *keyword, sure internally already raises an appropriate* ``AssertionError`` *with an assertion message so that you don't have to specify your own, but you can still use* ``assert`` *if you find it more semantic* Example: .. code:: python import sure "Name".lower().should.equal('name') ## or you can also use assert "Name".lower().should.equal('name') ## or still from sure import this assert this("Name".lower()).should.equal('name') ## also without the assert this("Name".lower()).should.equal('name') Any of the examples above will raise their own ``AssertionError`` with a meaningful error message. Synonyms -------- Sure provides you with a lot of synonyms so that you can pick the ones that makes more sense for your tests. Note that the examples below are merely illustrative, they work not only with numbers but with any of the assertions you read early in this documentation. Positive synonyms ~~~~~~~~~~~~~~~~~ .. code:: python (2 + 2).should.be.equal(4) (2 + 2).must.be.equal(4) (2 + 2).does.equals(4) (2 + 2).do.equals(4) Negative synonyms ~~~~~~~~~~~~~~~~~ .. code:: python from sure import expect (2).should_not.be.equal(3) (2).shouldnt.be.equal(3) (2).doesnt.equals(3) (2).does_not.equals(3) (2).doesnot.equals(3) (2).dont.equal(3) (2).do_not.equal(3) expect(3).to.not_be.equal(1) Chain-up synonyms ~~~~~~~~~~~~~~~~~ Any of those synonyms work as an alias to the assertion builder: - ``be`` - ``being`` - ``to`` - ``when`` - ``have`` - ``with_value`` .. code:: python from sure import expect {"foo": 1}.must.with_value.being.equal({"foo": 1}) {"foo": 1}.does.have.key("foo").being.with_value.equal(1) Equality synonyms ~~~~~~~~~~~~~~~~~ .. code:: python (2).should.equal(2) (2).should.equals(2) (2).should.eql(2) Positive boolean synonyms ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python import sure (not None).should.be.ok (not None).should.be.truthy (not None).should.be.true Negative boolean synonyms ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code:: python import sure False.should.be.falsy False.should.be.false False.should_not.be.true False.should_not.be.ok None.should_not.be.true None.should_not.be.ok Holy guacamole, how did you implement that feature ? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Differently of `ruby `__ python doesn't have `open classes `__, but `sure uses a technique `_ involving the module :py:mod:`ctypes` to write directly in the private ``__dict__`` of in-memory objects. For more information check out the `Forbidden Fruit `_ project. Yes, it is dangerous, non-pythonic and should not be used in production code. Although ``sure`` is here to be used **ONLY** in test code, therefore it should be running in **ONLY** possible environments: your local machine or your continuous-integration server. API Builtin Documentation ------------------------- .. automodule:: sure :members: .. automodule:: sure.core :members: .. automodule:: sure.old :members: Add custom assertions, chains and chain properties -------------------------------------------------- ``sure`` allows to add custom assertion methods, chain methods and chain properties. Custom assertion methods ~~~~~~~~~~~~~~~~~~~~~~~~ By default ``sure`` comes with a good amount of *assertion methods*. For example: - ``equals()`` - ``within()`` - ``contains()`` And plenty more. However, in some cases it makes sense to add custom *assertion methods* to improve the test experience. Let's assume you want to test your web application. Somewhere there is a ``Response`` class with a ``return_code`` property. We could do the following: .. code:: python response = Response(...) response.return_code.should.be.equal(200) This is already quiet readable, but wouldn't it be awesome do to something like this: .. code:: python response = Response(...) response.should.have.return_code(200) To achieve this the custom assertion methods come into play: .. code:: python from sure import assertion @assertion def return_code(self, expected_return_code): if self.negative: assert expected_return_code != self.obj.return_code, \ 'Expected return code matches' else: assert expected_return_code == self.obj.return_code, \ 'Expected return code does not match' response = Response(...) response.should.have.return_code(200) I'll admit you have to write the assertion method yourself, but the result is a great experience you don't want to miss. Chain methods ~~~~~~~~~~~~~ *chain methods* are similar to *assertion methods*. The only difference is that the *chain methods*, as the name implies, can be chained with further chains or assertions: .. code:: python from sure import chain @chain def header(self, header_name): # check if header name actually exists self.obj.headers.should.have.key(header_name) # return header value return self.obj.headers[header_name] response = Response(200, headers={'Content-Type': 'text/python'}) response.should.have.header('Content-Type').equals('text/python') Chain properties ~~~~~~~~~~~~~~~~ *chain properties* are simple properties which are available to build an assertion. Some of the default chain properties are: - ``be`` - ``to`` - ``when`` - ``have`` - ... Use the ``chainproperty`` decorator like the following to build your own *chain*: .. code:: python from sure import chainproperty, assertion class Foo: magic = 42 @chainproperty def having(self): return self @chainproperty def implement(self): return self @assertion def attribute(self, name): has_it = hasattr(self.obj, name) if self.negative: assert not has_it, 'Expected was that object {0} does not have attr {1}'.format( self.obj, name) else: assert has_it, 'Expected was that object {0} has attr {1}'.format( self.obj, name) # Build awesome assertion chains expect(Foo).having.attribute('magic') Foo.doesnt.implement.attribute('nomagic') Use custom assertion messages with ``ensure`` --------------------------------------------- With the ``ensure`` context manager *sure* provides an easy to use way to override the ``AssertionError`` message raised by ``sure``'s assertion methods. See the following example: .. code:: python import sure name = myapi.do_something_that_returns_string() with sure.ensure('the return value actually looks like: {0}', name): name.should.contain('whatever') In case ``name`` does not contain the string ``whatever`` it will raise an ``AssertionError`` exception with the message *the return value actually looks like: * (where ** would be the actual value of the variable ``name``) instead of *sure*'s default error message in that particular case. Only ``AssertionError`` exceptions are re-raised by ``sure.ensure()`` with the custom provided message. Every other exception will be ignored and handled as expected.