test_tasks.py

from __future__ import with_statement

from contextlib import contextmanager
from fudge import Fake, patched_context, with_fakes
import unittest
from nose.tools import eq_, raises, ok_
import random
import sys

import fabric
from fabric import tasks
from fabric.tasks import WrappedCallableTask, execute, Task
from fabric.api import run, env, settings, hosts, roles, hide, parallel
from fabric.network import from_dict
from fabric.exceptions import NetworkError

from utils import eq_, FabricTest, aborts, mock_streams
from server import server


def test_base_task_provides_undefined_name():
    task = tasks.Task()
    eq_("undefined", task.name)

@raises(NotImplementedError)
def test_base_task_raises_exception_on_call_to_run():
    task = tasks.Task()
    task.run()

class TestWrappedCallableTask(unittest.TestCase):
    def test_passes_unused_args_to_parent(self):
        args = [i for i in range(random.randint(1, 10))]

        def foo(): pass
        try:
            task = WrappedCallableTask(foo, *args)
        except TypeError:
            msg = "__init__ raised a TypeError, meaning args weren't handled"
            self.fail(msg)

    def test_passes_unused_kwargs_to_parent(self):
        random_range = range(random.randint(1, 10))
        kwargs = dict([("key_%s" % i, i) for i in random_range])

        def foo(): pass
        try:
            task = WrappedCallableTask(foo, **kwargs)
        except TypeError:
            self.fail(
                "__init__ raised a TypeError, meaning kwargs weren't handled")

    def test_allows_any_number_of_args(self):
        args = [i for i in range(random.randint(0, 10))]
        def foo(): pass
        task = tasks.WrappedCallableTask(foo, *args)

    def test_allows_any_number_of_kwargs(self):
        kwargs = dict([("key%d" % i, i) for i in range(random.randint(0, 10))])
        def foo(): pass
        task = tasks.WrappedCallableTask(foo, **kwargs)

    def test_run_is_wrapped_callable(self):
        def foo(): pass
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(task.wrapped, foo)

    def test_name_is_the_name_of_the_wrapped_callable(self):
        def foo(): pass
        foo.__name__ = "random_name_%d" % random.randint(1000, 2000)
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(task.name, foo.__name__)

    def test_reads_double_under_doc_from_callable(self):
        def foo(): pass
        foo.__doc__ = "Some random __doc__: %d" % random.randint(1000, 2000)
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(task.__doc__, foo.__doc__)

    def test_dispatches_to_wrapped_callable_on_run(self):
        random_value = "some random value %d" % random.randint(1000, 2000)
        def foo(): return random_value
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(random_value, task())

    def test_passes_all_regular_args_to_run(self):
        def foo(*args): return args
        random_args = tuple(
            [random.randint(1000, 2000) for i in range(random.randint(1, 5))]
        )
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(random_args, task(*random_args))

    def test_passes_all_keyword_args_to_run(self):
        def foo(**kwargs): return kwargs
        random_kwargs = {}
        for i in range(random.randint(1, 5)):
            random_key = ("foo", "bar", "baz", "foobar", "barfoo")[i]
            random_kwargs[random_key] = random.randint(1000, 2000)
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(random_kwargs, task(**random_kwargs))

    def test_calling_the_object_is_the_same_as_run(self):
        random_return = random.randint(1000, 2000)
        def foo(): return random_return
        task = tasks.WrappedCallableTask(foo)
        self.assertEqual(task(), task.run())


class TestTask(unittest.TestCase):
    def test_takes_an_alias_kwarg_and_wraps_it_in_aliases_list(self):
        random_alias = "alias_%d" % random.randint(100, 200)
        task = tasks.Task(alias=random_alias)
        self.assertTrue(random_alias in task.aliases)

    def test_aliases_are_set_based_on_provided_aliases(self):
        aliases = ["a_%d" % i for i in range(random.randint(1, 10))]
        task = tasks.Task(aliases=aliases)
        self.assertTrue(all([a in task.aliases for a in aliases]))

    def test_aliases_are_None_by_default(self):
        task = tasks.Task()
        self.assertTrue(task.aliases is None)

# Reminder: decorator syntax, e.g.:
#     @foo
#     def bar():...
#
# is semantically equivalent to:
#     def bar():...
#     bar = foo(bar)
#
# this simplifies testing :)

def test_decorator_incompatibility_on_task():
    from fabric.decorators import task, hosts, runs_once, roles
    def foo(): return "foo"
    foo = task(foo)

    # since we aren't setting foo to be the newly decorated thing, its cool
    hosts('me@localhost')(foo)
    runs_once(foo)
    roles('www')(foo)

def test_decorator_closure_hiding():
    """
    @task should not accidentally destroy decorated attributes from @hosts/etc
    """
    from fabric.decorators import task, hosts
    def foo():
        print env.host_string
    foo = task(hosts("me@localhost")(foo))
    eq_(["me@localhost"], foo.hosts)



#
# execute()
#

def dict_contains(superset, subset):
    """
    Assert that all key/val pairs in dict 'subset' also exist in 'superset'
    """
    for key, value in subset.iteritems():
        ok_(key in superset)
        eq_(superset[key], value)


class TestExecute(FabricTest):
    @with_fakes
    def test_calls_task_function_objects(self):
        """
        should execute the passed-in function object
        """
        execute(Fake(callable=True, expect_call=True))

    @with_fakes
    def test_should_look_up_task_name(self):
        """
        should also be able to handle task name strings
        """
        name = 'task1'
        commands = {name: Fake(callable=True, expect_call=True)}
        with patched_context(fabric.state, 'commands', commands):
            execute(name)

    @with_fakes
    def test_should_handle_name_of_Task_object(self):
        """
        handle corner case of Task object referrred to by name
        """
        name = 'task2'
        class MyTask(Task):
            run = Fake(callable=True, expect_call=True)
        mytask = MyTask()
        mytask.name = name
        commands = {name: mytask}
        with patched_context(fabric.state, 'commands', commands):
            execute(name)

    @aborts
    def test_should_abort_if_task_name_not_found(self):
        """
        should abort if given an invalid task name
        """
        execute('thisisnotavalidtaskname')

    @with_fakes
    def test_should_pass_through_args_kwargs(self):
        """
        should pass in any additional args, kwargs to the given task.
        """
        task = (
            Fake(callable=True, expect_call=True)
            .with_args('foo', biz='baz')
        )
        execute(task, 'foo', biz='baz')

    @with_fakes
    def test_should_honor_hosts_kwarg(self):
        """
        should use hosts kwarg to set run list
        """
        # Make two full copies of a host list
        hostlist = ['a', 'b', 'c']
        hosts = hostlist[:]
        # Side-effect which asserts the value of env.host_string when it runs
        def host_string():
            eq_(env.host_string, hostlist.pop(0))
        task = Fake(callable=True, expect_call=True).calls(host_string)
        with hide('everything'):
            execute(task, hosts=hosts)

    def test_should_honor_hosts_decorator(self):
        """
        should honor @hosts on passed-in task objects
        """
        # Make two full copies of a host list
        hostlist = ['a', 'b', 'c']
        @hosts(*hostlist[:])
        def task():
            eq_(env.host_string, hostlist.pop(0))
        with hide('running'):
            execute(task)

    def test_should_honor_roles_decorator(self):
        """
        should honor @roles on passed-in task objects
        """
        # Make two full copies of a host list
        roledefs = {'role1': ['a', 'b', 'c']}
        role_copy = roledefs['role1'][:]
        @roles('role1')
        def task():
            eq_(env.host_string, role_copy.pop(0))
        with settings(hide('running'), roledefs=roledefs):
            execute(task)

    @with_fakes
    def test_should_set_env_command_to_string_arg(self):
        """
        should set env.command to any string arg, if given
        """
        name = "foo"
        def command():
            eq_(env.command, name)
        task = Fake(callable=True, expect_call=True).calls(command)
        with patched_context(fabric.state, 'commands', {name: task}):
            execute(name)

    @with_fakes
    def test_should_set_env_command_to_name_attr(self):
        """
        should set env.command to TaskSubclass.name if possible
        """
        name = "foo"
        def command():
            eq_(env.command, name)
        task = (
            Fake(callable=True, expect_call=True)
            .has_attr(name=name)
            .calls(command)
        )
        execute(task)

    @with_fakes
    def test_should_set_all_hosts(self):
        """
        should set env.all_hosts to its derived host list
        """
        hosts = ['a', 'b']
        roledefs = {'r1': ['c', 'd']}
        roles = ['r1']
        exclude_hosts = ['a']
        def command():
            eq_(set(env.all_hosts), set(['b', 'c', 'd']))
        task = Fake(callable=True, expect_call=True).calls(command)
        with settings(hide('everything'), roledefs=roledefs):
            execute(
                task, hosts=hosts, roles=roles, exclude_hosts=exclude_hosts
            )

    @mock_streams('stdout')
    def test_should_print_executing_line_per_host(self):
        """
        should print "Executing" line once per host
        """
        def task():
            pass
        execute(task, hosts=['host1', 'host2'])
        eq_(sys.stdout.getvalue(), """[host1] Executing task 'task'
[host2] Executing task 'task'
""")

    @mock_streams('stdout')
    def test_should_not_print_executing_line_for_singletons(self):
        """
        should not print "Executing" line for non-networked tasks
        """
        def task():
            pass
        with settings(hosts=[]): # protect against really odd test bleed :(
            execute(task)
        eq_(sys.stdout.getvalue(), "")

    def test_should_return_dict_for_base_case(self):
        """
        Non-network-related tasks should return a dict w/ special key
        """
        def task():
            return "foo"
        eq_(execute(task), {'<local-only>': 'foo'})

    @server(port=2200)
    @server(port=2201)
    def test_should_return_dict_for_serial_use_case(self):
        """
        Networked but serial tasks should return per-host-string dict
        """
        ports = [2200, 2201]
        hosts = map(lambda x: '127.0.0.1:%s' % x, ports)
        def task():
            run("ls /simple")
            return "foo"
        with hide('everything'):
            eq_(execute(task, hosts=hosts), {
                '127.0.0.1:2200': 'foo',
                '127.0.0.1:2201': 'foo'
            })

    @server()
    def test_should_preserve_None_for_non_returning_tasks(self):
        """
        Tasks which don't return anything should still show up in the dict
        """
        def local_task():
            pass
        def remote_task():
            with hide('everything'):
                run("ls /simple")
        eq_(execute(local_task), {'<local-only>': None})
        with hide('everything'):
            eq_(
                execute(remote_task, hosts=[env.host_string]),
                {env.host_string: None}
            )

    def test_should_use_sentinel_for_tasks_that_errored(self):
        """
        Tasks which errored but didn't abort should contain an eg NetworkError
        """
        def task():
            run("whoops")
        host_string = 'localhost:1234'
        with settings(hide('everything'), skip_bad_hosts=True):
            retval = execute(task, hosts=[host_string])
        assert isinstance(retval[host_string], NetworkError)

    @server(port=2200)
    @server(port=2201)
    def test_parallel_return_values(self):
        """
        Parallel mode should still return values as in serial mode
        """
        @parallel
        @hosts('127.0.0.1:2200', '127.0.0.1:2201')
        def task():
            run("ls /simple")
            return env.host_string.split(':')[1]
        with hide('everything'):
            retval = execute(task)
        eq_(retval, {'127.0.0.1:2200': '2200', '127.0.0.1:2201': '2201'})

    @with_fakes
    def test_should_work_with_Task_subclasses(self):
        """
        should work for Task subclasses, not just WrappedCallableTask
        """
        class MyTask(Task):
            name = "mytask"
            run = Fake(callable=True, expect_call=True)
        mytask = MyTask()
        execute(mytask)


class TestExecuteEnvInteractions(FabricTest):
    def set_network(self):
        # Don't update env.host/host_string/etc
        pass

    @server(port=2200)
    @server(port=2201)
    def test_should_not_mutate_its_own_env_vars(self):
        """
        internal env changes should not bleed out, but task env changes should
        """
        # Task that uses a handful of features which involve env vars
        @parallel
        @hosts('username@127.0.0.1:2200', 'username@127.0.0.1:2201')
        def mytask():
            run("ls /simple")
        # Pre-assertions
        assertions = {
            'parallel': False,
            'all_hosts': [],
            'host': None,
            'hosts': [],
            'host_string': None
        }
        for key, value in assertions.items():
            eq_(env[key], value)
        # Run
        with hide('everything'):
            result = execute(mytask)
        eq_(len(result), 2)
        # Post-assertions
        for key, value in assertions.items():
            eq_(env[key], value)

    @server()
    def test_should_allow_task_to_modify_env_vars(self):
        @hosts('username@127.0.0.1:2200')
        def mytask():
            run("ls /simple")
            env.foo = "bar"
        with hide('everything'):
            execute(mytask)
        eq_(env.foo, "bar")
        eq_(env.host_string, None)