move kernel-test utilities to kernel.tests.utils

context managers and tools for starting kernels,
and sharing a *single* global kernel for many tests.

reduce the number of kernels started for IPython.kernel tests,
which should save some time.

IPython/kernel/tests/utils.py

@@ -0,0 +1,168 b''
+"""utilities for testing IPython kernels"""
+
+#-------------------------------------------------------------------------------
+#  Copyright (C) 2013  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-------------------------------------------------------------------------------
+
+#-------------------------------------------------------------------------------
+# Imports
+#-------------------------------------------------------------------------------
+
+import atexit
+
+from contextlib import contextmanager
+from subprocess import PIPE
+from Queue import Empty
+
+import nose.tools as nt
+
+from IPython.kernel import KernelManager
+
+#-------------------------------------------------------------------------------
+# Globals
+#-------------------------------------------------------------------------------
+
+STARTUP_TIMEOUT = 60
+TIMEOUT = 15
+
+KM = None
+KC = None
+
+#-------------------------------------------------------------------------------
+# code
+#-------------------------------------------------------------------------------
+
+
+def start_new_kernel():
+    """start a new kernel, and return its Manager and Client"""
+    km = KernelManager()
+    km.start_kernel(stdout=PIPE, stderr=PIPE)
+    kc = km.client()
+    kc.start_channels()
+    
+    msg_id = kc.kernel_info()
+    kc.get_shell_msg(block=True, timeout=STARTUP_TIMEOUT)
+    flush_channels(kc)
+    return km, kc
+
+def flush_channels(kc=None):
+    """flush any messages waiting on the queue"""
+    from .test_message_spec import validate_message
+    
+    if kc is None:
+        kc = KC
+    for channel in (kc.shell_channel, kc.iopub_channel):
+        while True:
+            try:
+                msg = channel.get_msg(block=True, timeout=0.1)
+            except Empty:
+                break
+            else:
+                validate_message(msg)
+
+
+def execute(code='', kc=None, **kwargs):
+    """wrapper for doing common steps for validating an execution request"""
+    from .test_message_spec import validate_message
+    if kc is None:
+        kc = KC
+    msg_id = kc.execute(code=code, **kwargs)
+    reply = kc.get_shell_msg(timeout=TIMEOUT)
+    validate_message(reply, 'execute_reply', msg_id)
+    busy = kc.get_iopub_msg(timeout=TIMEOUT)
+    validate_message(busy, 'status', msg_id)
+    nt.assert_equal(busy['content']['execution_state'], 'busy')
+    
+    if not kwargs.get('silent'):
+        pyin = kc.get_iopub_msg(timeout=TIMEOUT)
+        validate_message(pyin, 'pyin', msg_id)
+        nt.assert_equal(pyin['content']['code'], code)
+    
+    return msg_id, reply['content']
+
+def start_global_kernel():
+    """start the global kernel (if it isn't running) and return its client"""
+    global KM, KC
+    print KM, KC
+    if KM is None:
+        KM, KC = start_new_kernel()
+        atexit.register(stop_global_kernel)
+    return KC
+
+@contextmanager
+def kernel():
+    """Context manager for the global kernel instance
+    
+    Should be used for most kernel tests
+    
+    Returns
+    -------
+    kernel_client: connected KernelClient instance
+    """
+    yield start_global_kernel()
+
+def uses_kernel(test_f):
+    """Decorator for tests that use the global kernel"""
+    def wrapped_test():
+        with kernel() as kc:
+            test_f(kc)
+    wrapped_test.__doc__ = test_f.__doc__
+    wrapped_test.__name__ = test_f.__name__
+    return wrapped_test
+
+def stop_global_kernel():
+    """Stop the global shared kernel instance, if it exists"""
+    global KM, KC
+    KC.stop_channels()
+    KC = None
+    if KM is None:
+        return
+    KM.shutdown_kernel(now=True)
+    KM = None
+
+@contextmanager
+def new_kernel():
+    """Context manager for a new kernel in a subprocess
+    
+    Should only be used for tests where the kernel must not be re-used.
+    
+    Returns
+    -------
+    kernel_client: connected KernelClient instance
+    """
+    km, kc = start_new_kernel()
+    try:
+        yield kc
+    finally:
+        kc.stop_channels()
+        km.shutdown_kernel()
+
+
+def assemble_output(iopub):
+    """assemble stdout/err from an execution"""
+    stdout = ''
+    stderr = ''
+    while True:
+        msg = iopub.get_msg(block=True, timeout=1)
+        msg_type = msg['msg_type']
+        content = msg['content']
+        if msg_type == 'status' and content['execution_state'] == 'idle':
+            # idle message signals end of output
+            break
+        elif msg['msg_type'] == 'stream':
+            if content['name'] == 'stdout':
+                stdout = stdout + content['data']
+            elif content['name'] == 'stderr':
+                stderr = stderr + content['data']
+            else:
+                raise KeyError("bad stream: %r" % content['name'])
+        else:
+            # other output, ignored
+            pass
+    return stdout, stderr
+
+
+

IPython/kernel/tests/__init__.py

@@ -0,0 +1,58 b''
+"""test the IPython Kernel"""
+
+#-------------------------------------------------------------------------------
+#  Copyright (C) 2013  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-------------------------------------------------------------------------------
+
+#-------------------------------------------------------------------------------
+# Imports
+#-------------------------------------------------------------------------------
+
+import os
+import shutil
+import sys
+import tempfile
+
+import nose.tools as nt
+
+from IPython.testing import decorators as dec
+from IPython.utils import path, py3compat
+
+from .utils import new_kernel, kernel, TIMEOUT, assemble_output, execute, flush_channels
+
+#-------------------------------------------------------------------------------
+# Tests
+#-------------------------------------------------------------------------------
+IPYTHONDIR = None
+save_env = None
+save_get_ipython_dir = None
+
+def setup():
+    """setup temporary IPYTHONDIR for tests"""
+    global IPYTHONDIR
+    global save_env
+    global save_get_ipython_dir
+    
+    IPYTHONDIR = tempfile.mkdtemp()
+
+    save_env = os.environ.copy()
+    os.environ["IPYTHONDIR"] = IPYTHONDIR
+
+    save_get_ipython_dir = path.get_ipython_dir
+    path.get_ipython_dir = lambda : IPYTHONDIR
+    print 'setup'
+
+
+def teardown():
+    print 'tearing down'
+    path.get_ipython_dir = save_get_ipython_dir
+    os.environ = save_env
+    
+    try:
+        shutil.rmtree(IPYTHONDIR)
+    except (OSError, IOError):
+        # no such file
+        pass

IPython/kernel/tests/test_kernel.py

@@ -11,104 +11,18 b''
 # Imports
 #-------------------------------------------------------------------------------
 
-import os
-import shutil
 import sys
-import tempfile
-
-from contextlib import contextmanager
-from subprocess import PIPE
 
 import nose.tools as nt
 
-from IPython.kernel import KernelManager
-from IPython.kernel.tests.test_message_spec import execute, flush_channels
 from IPython.testing import decorators as dec, tools as tt
-from IPython.utils import path, py3compat
+from IPython.utils import py3compat
+
+from .utils import new_kernel, kernel, TIMEOUT, assemble_output, execute, flush_channels
 
 #-------------------------------------------------------------------------------
 # Tests
 #-------------------------------------------------------------------------------
-IPYTHONDIR = None
-save_env = None
-save_get_ipython_dir = None
-
-STARTUP_TIMEOUT = 60
-TIMEOUT = 15
-
-def setup():
-    """setup temporary IPYTHONDIR for tests"""
-    global IPYTHONDIR
-    global save_env
-    global save_get_ipython_dir
-    
-    IPYTHONDIR = tempfile.mkdtemp()
-
-    save_env = os.environ.copy()
-    os.environ["IPYTHONDIR"] = IPYTHONDIR
-
-    save_get_ipython_dir = path.get_ipython_dir
-    path.get_ipython_dir = lambda : IPYTHONDIR
-
-
-def teardown():
-    path.get_ipython_dir = save_get_ipython_dir
-    os.environ = save_env
-    
-    try:
-        shutil.rmtree(IPYTHONDIR)
-    except (OSError, IOError):
-        # no such file
-        pass
-
-
-@contextmanager
-def new_kernel():
-    """start a kernel in a subprocess, and wait for it to be ready
-    
-    Returns
-    -------
-    kernel_manager: connected KernelManager instance
-    """
-    KM = KernelManager()
-
-    KM.start_kernel(stdout=PIPE, stderr=PIPE)
-    KC = KM.client()
-    KC.start_channels()
-    
-    # wait for kernel to be ready
-    KC.shell_channel.execute("import sys")
-    KC.shell_channel.get_msg(block=True, timeout=STARTUP_TIMEOUT)
-    flush_channels(KC)
-    try:
-        yield KC
-    finally:
-        KC.stop_channels()
-        KM.shutdown_kernel()
-
-
-def assemble_output(iopub):
-    """assemble stdout/err from an execution"""
-    stdout = ''
-    stderr = ''
-    while True:
-        msg = iopub.get_msg(block=True, timeout=1)
-        msg_type = msg['msg_type']
-        content = msg['content']
-        if msg_type == 'status' and content['execution_state'] == 'idle':
-            # idle message signals end of output
-            break
-        elif msg['msg_type'] == 'stream':
-            if content['name'] == 'stdout':
-                stdout = stdout + content['data']
-            elif content['name'] == 'stderr':
-                stderr = stderr + content['data']
-            else:
-                raise KeyError("bad stream: %r" % content['name'])
-        else:
-            # other output, ignored
-            pass
-    return stdout, stderr
 
 
 def _check_mp_mode(kc, expected=False, stream="stdout"):
@@ -123,7 +37,7 b' def _check_mp_mode(kc, expected=False, stream="stdout"):'
 
 def test_simple_print():
     """simple print statement in kernel"""
-    with new_kernel() as kc:
+    with kernel() as kc:
         iopub = kc.iopub_channel
         msg_id, content = execute(kc=kc, code="print ('hi')")
         stdout, stderr = assemble_output(iopub)
@@ -165,7 +79,7 b' def test_subprocess_print():'
 
 def test_subprocess_noprint():
     """mp.Process without print doesn't trigger iostream mp_mode"""
-    with new_kernel() as kc:
+    with kernel() as kc:
         iopub = kc.iopub_channel
         
         np = 5
@@ -210,7 +124,7 b' def test_subprocess_error():'
 
 def test_raw_input():
     """test [raw_]input"""
-    with new_kernel() as kc:
+    with kernel() as kc:
         iopub = kc.iopub_channel
         
         input_f = "input" if py3compat.PY3 else "raw_input"
@@ -232,7 +146,7 b' def test_raw_input():'
 @dec.skipif(py3compat.PY3)
 def test_eval_input():
     """test input() on Python 2"""
-    with new_kernel() as kc:
+    with kernel() as kc:
         iopub = kc.iopub_channel
         
         input_f = "input" if py3compat.PY3 else "raw_input"

IPython/kernel/tests/test_message_spec.py

@@ -1,7 +1,7 b''
-"""Test suite for our zeromq-based messaging specification.
+"""Test suite for our zeromq-based message specification.
 """
 #-----------------------------------------------------------------------------
-#  Copyright (C) 2010-2011  The IPython Development Team
+#  Copyright (C) 2010  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.
@@ -19,72 +19,21 b' from IPython.utils.traitlets import ('
     HasTraits, TraitError, Bool, Unicode, Dict, Integer, List, Enum, Any,
 )
 
+from .utils import TIMEOUT, start_global_kernel, flush_channels, execute
+
 #-----------------------------------------------------------------------------
-# Global setup and utilities
+# Globals
 #-----------------------------------------------------------------------------
-
-STARTUP_TIMEOUT = 60
-TIMEOUT = 15
+KC = None
 
 def setup():
-    global KM, KC
-    KM = KernelManager()
-    KM.start_kernel(stdout=PIPE, stderr=PIPE)
-    KC = KM.client()
-    KC.start_channels()
-    
-    # wait for kernel to be ready
-    try:
-        msg = KC.iopub_channel.get_msg(block=True, timeout=STARTUP_TIMEOUT)
-    except Empty:
-        pass
-    msg_id = KC.kernel_info()
-    KC.get_shell_msg(block=True, timeout=STARTUP_TIMEOUT)
-    flush_channels()
-
-
-def teardown():
-    KC.stop_channels()
-    KM.shutdown_kernel()
-
-
-def flush_channels(kc=None):
-    """flush any messages waiting on the queue"""
-    if kc is None:
-        kc = KC
-    for channel in (kc.shell_channel, kc.iopub_channel):
-        while True:
-            try:
-                msg = channel.get_msg(block=True, timeout=0.1)
-            except Empty:
-                break
-            else:
-                validate_message(msg)
-
-
-def execute(code='', kc=None, **kwargs):
-    """wrapper for doing common steps for validating an execution request"""
-    if kc is None:
-        kc = KC
-    msg_id = kc.execute(code=code, **kwargs)
-    reply = kc.get_shell_msg(timeout=TIMEOUT)
-    validate_message(reply, 'execute_reply', msg_id)
-    busy = kc.get_iopub_msg(timeout=TIMEOUT)
-    validate_message(busy, 'status', msg_id)
-    nt.assert_equal(busy['content']['execution_state'], 'busy')
-    
-    if not kwargs.get('silent'):
-        pyin = kc.get_iopub_msg(timeout=TIMEOUT)
-        validate_message(pyin, 'pyin', msg_id)
-        nt.assert_equal(pyin['content']['code'], code)
-    
-    return msg_id, reply['content']
+    global KC
+    KC = start_global_kernel()
 
 #-----------------------------------------------------------------------------
-# MSG Spec References
+# Message Spec References
 #-----------------------------------------------------------------------------
 
-
 class Reference(HasTraits):
 
     """