Document how test_message_spec works

IPython/zmq/tests/test_message_spec.py

@@ -1,452 +1,465 b''
 """Test suite for our zeromq-based messaging specification.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING.txt, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 import re
 import sys
 import time
 from subprocess import PIPE
 from Queue import Empty
 
 import nose.tools as nt
 
 from ..blockingkernelmanager import BlockingKernelManager
 
 
 from IPython.testing import decorators as dec
 from IPython.utils import io
 from IPython.utils.traitlets import (
     HasTraits, TraitError, Bool, Unicode, Dict, Integer, List, Enum,
 )
 
 #-----------------------------------------------------------------------------
 # Global setup and utilities
 #-----------------------------------------------------------------------------
 
 def setup():
     global KM
     KM = BlockingKernelManager()
 
     KM.start_kernel(stdout=PIPE, stderr=PIPE)
     KM.start_channels()
     
     # wait for kernel to be ready
     KM.shell_channel.execute("pass")
     KM.shell_channel.get_msg(block=True, timeout=5)
     flush_channels()
 
 
 def teardown():
     KM.stop_channels()
     KM.shutdown_kernel()
 
 
 def flush_channels():
     """flush any messages waiting on the queue"""
     for channel in (KM.shell_channel, KM.sub_channel):
         while True:
             try:
                 msg = channel.get_msg(block=True, timeout=0.1)
             except Empty:
                 break
             else:
                 list(validate_message(msg))
 
 
 def execute(code='', **kwargs):
     """wrapper for doing common steps for validating an execution request"""
     shell = KM.shell_channel
     sub = KM.sub_channel
     
     msg_id = shell.execute(code=code, **kwargs)
     reply = shell.get_msg(timeout=2)
     list(validate_message(reply, 'execute_reply', msg_id))
     busy = sub.get_msg(timeout=2)
     list(validate_message(busy, 'status', msg_id))
     nt.assert_equal(busy['content']['execution_state'], 'busy')
     
     if not kwargs.get('silent'):
         pyin = sub.get_msg(timeout=2)
         list(validate_message(pyin, 'pyin', msg_id))
         nt.assert_equal(pyin['content']['code'], code)
     
     return msg_id, reply['content']
 
 #-----------------------------------------------------------------------------
 # MSG Spec References
 #-----------------------------------------------------------------------------
 
 
 class Reference(HasTraits):
     
+    """
+    Base class for message spec specification testing.
+
+    This class is the core of the message specification test.  The
+    idea is that child classes implement trait attributes for each
+    message keys, so that message keys can be tested against these
+    traits using :meth:`check` method.
+
+    """
+
     def check(self, d):
         """validate a dict against our traits"""
         for key in self.trait_names():
             yield nt.assert_true(key in d, "Missing key: %r, should be found in %s" % (key, d))
             # FIXME: always allow None, probably not a good idea
             if d[key] is None:
                 continue
             try:
                 setattr(self, key, d[key])
             except TraitError as e:
                 yield nt.assert_true(False, str(e))
 
 
 class RMessage(Reference):
     msg_id = Unicode()
     msg_type = Unicode()
     header = Dict()
     parent_header = Dict()
     content = Dict()
 
 class RHeader(Reference):
     msg_id = Unicode()
     msg_type = Unicode()
     session = Unicode()
     username = Unicode()
 
 class RContent(Reference):
     status = Enum((u'ok', u'error'))
 
 
 class ExecuteReply(Reference):
     execution_count = Integer()
     status = Enum((u'ok', u'error'))
     
     def check(self, d):
         for tst in Reference.check(self, d):
             yield tst
         if d['status'] == 'ok':
             for tst in ExecuteReplyOkay().check(d):
                 yield tst
         elif d['status'] == 'error':
             for tst in ExecuteReplyError().check(d):
                 yield tst
 
 
 class ExecuteReplyOkay(Reference):
     payload = List(Dict)
     user_variables = Dict()
     user_expressions = Dict()
 
 
 class ExecuteReplyError(Reference):
     ename = Unicode()
     evalue = Unicode()
     traceback = List(Unicode)
 
 
 class OInfoReply(Reference):
     name = Unicode()
     found = Bool()
     ismagic = Bool()
     isalias = Bool()
     namespace = Enum((u'builtin', u'magics', u'alias', u'Interactive'))
     type_name = Unicode()
     string_form = Unicode()
     base_class = Unicode()
     length = Integer()
     file = Unicode()
     definition = Unicode()
     argspec = Dict()
     init_definition = Unicode()
     docstring = Unicode()
     init_docstring = Unicode()
     class_docstring = Unicode()
     call_def = Unicode()
     call_docstring = Unicode()
     source = Unicode()
     
     def check(self, d):
         for tst in Reference.check(self, d):
             yield tst
         if d['argspec'] is not None:
             for tst in ArgSpec().check(d['argspec']):
                 yield tst
 
 
 class ArgSpec(Reference):
     args = List(Unicode)
     varargs = Unicode()
     varkw = Unicode()
     defaults = List()
 
 
 class Status(Reference):
     execution_state = Enum((u'busy', u'idle'))
 
 
 class CompleteReply(Reference):
     matches = List(Unicode)
 
 
 # IOPub messages
 
 class PyIn(Reference):
     code = Unicode()
     execution_count = Integer()
 
 
 PyErr = ExecuteReplyError
 
 
 class Stream(Reference):
     name = Enum((u'stdout', u'stderr'))
     data = Unicode()
 
 
 mime_pat = re.compile(r'\w+/\w+')
 
 class DisplayData(Reference):
     source = Unicode()
     metadata = Dict()
     data = Dict()
     def _data_changed(self, name, old, new):
         for k,v in new.iteritems():
             nt.assert_true(mime_pat.match(k))
             nt.assert_true(isinstance(v, basestring), "expected string data, got %r" % v)
 
 
 class PyOut(Reference):
     execution_count = Integer()
     data = Dict()
     def _data_changed(self, name, old, new):
         for k,v in new.iteritems():
             nt.assert_true(mime_pat.match(k))
             nt.assert_true(isinstance(v, basestring), "expected string data, got %r" % v)
 
 
 references = {
     'execute_reply' : ExecuteReply(),
     'object_info_reply' : OInfoReply(),
     'status' : Status(),
     'complete_reply' : CompleteReply(),
     'pyin' : PyIn(),
     'pyout' : PyOut(),
     'pyerr' : PyErr(),
     'stream' : Stream(),
     'display_data' : DisplayData(),
 }
+"""
+Specifications of `content` part of the reply messages.
+"""
 
 
 def validate_message(msg, msg_type=None, parent=None):
     """validate a message
     
     This is a generator, and must be iterated through to actually
     trigger each test.
     
     If msg_type and/or parent are given, the msg_type and/or parent msg_id
     are compared with the given values.
     """
     RMessage().check(msg)
     if msg_type:
         yield nt.assert_equal(msg['msg_type'], msg_type)
     if parent:
         yield nt.assert_equal(msg['parent_header']['msg_id'], parent)
     content = msg['content']
     ref = references[msg['msg_type']]
     for tst in ref.check(content):
         yield tst
 
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 # Shell channel
 
 @dec.parametric
 def test_execute():
     flush_channels()
     
     shell = KM.shell_channel
     msg_id = shell.execute(code='x=1')
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'execute_reply', msg_id):
         yield tst
 
 
 @dec.parametric
 def test_execute_silent():
     flush_channels()
     msg_id, reply = execute(code='x=1', silent=True)
     
     # flush status=idle
     status = KM.sub_channel.get_msg(timeout=2)
     for tst in validate_message(status, 'status', msg_id):
         yield tst
     nt.assert_equal(status['content']['execution_state'], 'idle')
 
     yield nt.assert_raises(Empty, KM.sub_channel.get_msg, timeout=0.1)
     count = reply['execution_count']
     
     msg_id, reply = execute(code='x=2', silent=True)
     
     # flush status=idle
     status = KM.sub_channel.get_msg(timeout=2)
     for tst in validate_message(status, 'status', msg_id):
         yield tst
     yield nt.assert_equal(status['content']['execution_state'], 'idle')
     
     yield nt.assert_raises(Empty, KM.sub_channel.get_msg, timeout=0.1)
     count_2 = reply['execution_count']
     yield nt.assert_equal(count_2, count)
 
 
 @dec.parametric
 def test_execute_error():
     flush_channels()
     
     msg_id, reply = execute(code='1/0')
     yield nt.assert_equal(reply['status'], 'error')
     yield nt.assert_equal(reply['ename'], 'ZeroDivisionError')
     
     pyerr = KM.sub_channel.get_msg(timeout=2)
     for tst in validate_message(pyerr, 'pyerr', msg_id):
         yield tst
 
 
 def test_execute_inc():
     """execute request should increment execution_count"""
     flush_channels()
 
     msg_id, reply = execute(code='x=1')
     count = reply['execution_count']
     
     flush_channels()
     
     msg_id, reply = execute(code='x=2')
     count_2 = reply['execution_count']
     nt.assert_equal(count_2, count+1)
 
 
 def test_user_variables():
     flush_channels()
 
     msg_id, reply = execute(code='x=1', user_variables=['x'])
     user_variables = reply['user_variables']
     nt.assert_equal(user_variables, {u'x' : u'1'})
 
 
 def test_user_expressions():
     flush_channels()
 
     msg_id, reply = execute(code='x=1', user_expressions=dict(foo='x+1'))
     user_expressions = reply['user_expressions']
     nt.assert_equal(user_expressions, {u'foo' : u'2'})
 
 
 @dec.parametric
 def test_oinfo():
     flush_channels()
 
     shell = KM.shell_channel
     
     msg_id = shell.object_info('a')
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'object_info_reply', msg_id):
         yield tst
 
 
 @dec.parametric
 def test_oinfo_found():
     flush_channels()
 
     shell = KM.shell_channel
     
     msg_id, reply = execute(code='a=5')
     
     msg_id = shell.object_info('a')
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'object_info_reply', msg_id):
         yield tst
     content = reply['content']
     yield nt.assert_true(content['found'])
     argspec = content['argspec']
     yield nt.assert_true(argspec is None, "didn't expect argspec dict, got %r" % argspec)
 
 
 @dec.parametric
 def test_oinfo_detail():
     flush_channels()
 
     shell = KM.shell_channel
     
     msg_id, reply = execute(code='ip=get_ipython()')
     
     msg_id = shell.object_info('ip.object_inspect', detail_level=2)
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'object_info_reply', msg_id):
         yield tst
     content = reply['content']
     yield nt.assert_true(content['found'])
     argspec = content['argspec']
     yield nt.assert_true(isinstance(argspec, dict), "expected non-empty argspec dict, got %r" % argspec)
     yield nt.assert_equal(argspec['defaults'], [0])
 
 
 @dec.parametric
 def test_oinfo_not_found():
     flush_channels()
 
     shell = KM.shell_channel
     
     msg_id = shell.object_info('dne')
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'object_info_reply', msg_id):
         yield tst
     content = reply['content']
     yield nt.assert_false(content['found'])
 
 
 @dec.parametric
 def test_complete():
     flush_channels()
 
     shell = KM.shell_channel
     
     msg_id, reply = execute(code="alpha = albert = 5")
     
     msg_id = shell.complete('al', 'al', 2)
     reply = shell.get_msg(timeout=2)
     for tst in validate_message(reply, 'complete_reply', msg_id):
         yield tst
     matches = reply['content']['matches']
     for name in ('alpha', 'albert'):
         yield nt.assert_true(name in matches, "Missing match: %r" % name)
 
 
 # IOPub channel
 
 
 @dec.parametric
 def test_stream():
     flush_channels()
 
     msg_id, reply = execute("print('hi')")
 
     stdout = KM.sub_channel.get_msg(timeout=2)
     for tst in validate_message(stdout, 'stream', msg_id):
         yield tst
     content = stdout['content']
     yield nt.assert_equal(content['name'], u'stdout')
     yield nt.assert_equal(content['data'], u'hi\n')
 
 
 @dec.parametric
 def test_display_data():
     flush_channels()
 
     msg_id, reply = execute("from IPython.core.display import display; display(1)")
     
     display = KM.sub_channel.get_msg(timeout=2)
     for tst in validate_message(display, 'display_data', parent=msg_id):
         yield tst
     data = display['content']['data']
     yield nt.assert_equal(data['text/plain'], u'1')