Add tests for the help command & --help options

Move the parser setup from bootstrap_with_global_options to bootstrap,
so all API objects have access to it.

Add some CLI tests for the help system.

Part of the effort for https://fedorahosted.org/freeipa/ticket/3060

ipalib/plugable.py

@@ -456,7 +456,7 @@ class API(DictProxy):
     def isdone(self, name):
         return name in self.__done
 
-    def bootstrap(self, **overrides):
+    def bootstrap(self, parser=None, **overrides):
         """
         Initialize environment variables and logging.
         """
@@ -516,6 +516,10 @@ class API(DictProxy):
             log.error('Cannot open log file %r: %s', self.env.log, e)
             return
 
+        if not parser:
+            parser = self.build_global_parser()
+        object.__setattr__(self, 'parser', parser)
+
     def build_global_parser(self, parser=None, context=None):
         """
         Add global options to an optparse.OptionParser instance.
@@ -592,8 +596,7 @@ class API(DictProxy):
             overrides['webui_prod'] = options.prod
         if context is not None:
             overrides['context'] = context
-        self.bootstrap(**overrides)
-        object.__setattr__(self, 'parser', parser)
+        self.bootstrap(parser, **overrides)
         return (options, args)
 
     def load_plugins(self):

tests/test_cmdline/test_help.py

@@ -0,0 +1,130 @@
+# Authors: Petr Viktorin <pviktori@redhat.com>
+#
+# Copyright (C) 2012  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import sys
+import contextlib
+import StringIO
+
+from nose.tools import assert_raises  # pylint: disable=E0611
+
+from ipalib import api, errors
+from ipalib.plugins.user import user_add
+
+
+class CLITestContext(object):
+    """Context manager that replaces stdout & stderr, and catches SystemExit
+
+    Whatever was printed to the streams is available in ``stdout`` and
+    ``stderr`` attrributes once the with statement finishes.
+
+    When exception is given, asserts that exception is raised. The exception
+    will be available in the ``exception`` attribute.
+    """
+    def __init__(self, exception=None):
+        self.exception = exception
+
+    def __enter__(self):
+        self.old_streams = sys.stdout, sys.stderr
+        self.stdout_fileobj = sys.stdout = StringIO.StringIO()
+        self.stderr_fileobj = sys.stderr = StringIO.StringIO()
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        sys.stdout, sys.stderr = self.old_streams
+        self.stdout = self.stdout_fileobj.getvalue()
+        self.stderr = self.stderr_fileobj.getvalue()
+        self.stdout_fileobj.close()
+        self.stderr_fileobj.close()
+        if self.exception:
+            assert isinstance(exc_value, self.exception), exc_value
+            self.exception = exc_value
+            return True
+
+
+def test_ipa_help():
+    """Test that `ipa help` only writes to stdout"""
+    with CLITestContext() as ctx:
+        return_value = api.Backend.cli.run(['help'])
+    assert return_value == 0
+    assert ctx.stderr == ''
+
+
+def test_ipa_without_arguments():
+    """Test that `ipa` errors out, and prints the help to stderr"""
+    with CLITestContext(exception=SystemExit) as ctx:
+        api.Backend.cli.run([])
+    assert ctx.exception.code == 2
+    assert ctx.stdout == ''
+    assert 'Error: Command not specified' in ctx.stderr
+
+    with CLITestContext() as help_ctx:
+        api.Backend.cli.run(['help'])
+    assert help_ctx.stdout in ctx.stderr
+
+
+def test_bare_topic():
+    """Test that `ipa user` errors out, and prints the help to stderr
+
+    This is because `user` is a topic, not a command, so `ipa user` doesn't
+    match our usage string. The help should be accessed using `ipa help user`.
+    """
+    with CLITestContext(exception=errors.CommandError) as ctx:
+        api.Backend.cli.run(['user'])
+    assert ctx.exception.name == 'user'
+    assert ctx.stdout == ''
+
+    with CLITestContext() as help_ctx:
+        return_value = api.Backend.cli.run(['help', 'user'])
+    assert return_value == 0
+    assert help_ctx.stdout in ctx.stderr
+
+
+def test_command_help():
+    """Test that `help user-add` & `user-add -h` are equivalent and contain doc
+    """
+    with CLITestContext() as help_ctx:
+        return_value = api.Backend.cli.run(['help', 'user-add'])
+    assert return_value == 0
+    assert help_ctx.stderr == ''
+
+    with CLITestContext(exception=SystemExit) as h_ctx:
+        api.Backend.cli.run(['user-add', '-h'])
+    assert h_ctx.exception.code == 0
+    assert h_ctx.stderr == ''
+
+    assert h_ctx.stdout == help_ctx.stdout
+    assert unicode(user_add.__doc__) in help_ctx.stdout
+
+
+def test_ambiguous_command_or_topic():
+    """Test that `help ping` & `ping -h` are NOT equivalent
+
+    One is a topic, the other is a command
+    """
+    with CLITestContext() as help_ctx:
+        return_value = api.Backend.cli.run(['help', 'ping'])
+    assert return_value == 0
+    assert help_ctx.stderr == ''
+
+    with CLITestContext(exception=SystemExit) as h_ctx:
+        api.Backend.cli.run(['ping', '-h'])
+    assert h_ctx.exception.code == 0
+    assert h_ctx.stderr == ''
+
+    assert h_ctx.stdout != help_ctx.stdout