Use cliff for CLI layer

This commit makes stestr use cliff[1] for CLI layer. The cliff project
provides a lot of advantages for stestr cli which has subcommands.
Instead of just using argparse, we should leverage cliff to provide a
more plished CLI experience.

[1] https://pypi.python.org/pypi/cliff

Closes Issue #62

requirements.txt

@@ -3,6 +3,7 @@
 # process, which may cause wedges in the gate later.
 future
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
+cliff>=2.8.0 # Apache-2.0
 python-subunit>=0.18.0 # Apache-2.0/BSD
 fixtures>=3.0.0 # Apache-2.0/BSD
 six>=1.10.0 # MIT

setup.cfg

@@ -29,6 +29,15 @@ packages =
 console_scripts =
     stestr = stestr.cli:main
 
+stestr.cm =
+    run = stestr.commands.run:Run
+    failing = stestr.commands.failing:Failing
+    init = stestr.commands.init:Init
+    last = stestr.commands.last:Last
+    list = stestr.commands.list:List
+    load = stestr.commands.load:Load
+    slowest = stestr.commands.slowest:Slowest
+
 [extras]
 sql =
     subunit2sql>=1.8.0

stestr/cli.py

@@ -10,36 +10,41 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import argparse
-import importlib
-import os
 import sys
 
+from cliff import app
+from cliff import commandmanager
 from stestr import version
 
 __version__ = version.version_info.version_string_with_vcs()
 
 
-class StestrCLI(object):
-
-    commands = ['run', 'list', 'slowest', 'failing', 'last', 'init', 'load']
-    command_module = 'stestr.commands.'
+class StestrCLI(app.App):
 
     def __init__(self):
-        self.parser = self._get_parser()
-
-    def _get_parser(self):
-        self.command_dict = {}
-        parser = argparse.ArgumentParser()
-        self._set_common_opts(parser)
-        subparsers = parser.add_subparsers(help='command help')
-        for cmd in self.commands:
-            self.command_dict[cmd] = importlib.import_module(
-                self.command_module + cmd)
-            help_str = self.command_dict[cmd].get_cli_help()
-            command_parser = subparsers.add_parser(cmd, help=help_str)
-            self.command_dict[cmd].set_cli_opts(command_parser)
-            command_parser.set_defaults(func=self.command_dict[cmd].run)
+        super(StestrCLI, self).__init__(
+            description='stestr application',
+            version=__version__,
+            command_manager=commandmanager.CommandManager('stestr.cm'),
+            deferred_help=True,
+            )
+
+    def initialize_app(self, argv):
+        self.LOG.debug('initialize_app')
+
+    def prepare_to_run_command(self, cmd):
+        self.LOG.debug('prepare_to_run_command %s', cmd.__class__.__name__)
+
+    def clean_up(self, cmd, result, err):
+        self.LOG.debug('clean_up %s', cmd.__class__.__name__)
+        if err:
+            self.LOG.debug('got an error: %s', err)
+
+    def build_option_parser(self, description, version, argparse_kwargs=None):
+        parser = super(StestrCLI,
+                       self).build_option_parser(description, version,
+                                                 argparse_kwargs)
+        parser = self._set_common_opts(parser)
         return parser
 
     def _set_common_opts(self, parser):
@@ -49,12 +54,6 @@ def _set_common_opts(self, parser):
                                  "path lookups but does not affect paths "
                                  "supplied to the command.",
                             default=None, type=str)
-        parser.add_argument("-q", "--quiet", action="store_true",
-                            default=False,
-                            help="Turn off output other than the primary "
-                                 "output for a command and any errors.")
-        parser.add_argument('--version', action='version',
-                            version=__version__)
         parser.add_argument('--config', '-c', dest='config',
                             default='.stestr.conf',
                             help="Set a stestr config file to use with this "
@@ -88,25 +87,13 @@ def _set_common_opts(self, parser):
                                  "both this and the corresponding config file "
                                  "option are set this value will be used.")
 
+        return parser
+
 
-def main():
+def main(argv=sys.argv[1:]):
     cli = StestrCLI()
-    args = cli.parser.parse_known_args()
-    if args[0].here:
-        os.chdir(args[0].here)
-    # NOTE(mtreinish): Make sure any subprocesses launch the same version of
-    # python being run here
-    if 'PYTHON' not in os.environ:
-        os.environ['PYTHON'] = sys.executable
-    if hasattr(args[0], 'func'):
-        sys.exit(args[0].func(args))
-    else:
-        cli.parser.print_help()
-        # NOTE(andreaf) This point is reached only when using Python 3.x.
-        # Python 2.x fails with return code 2 in case of no
-        # command, so using 2 for consistency
-        sys.exit(2)
+    return cli.run(argv)
 
 
 if __name__ == '__main__':
-    main()
+    sys.exit(main(sys.argv[1:]))

stestr/commands/failing.py

@@ -14,24 +14,33 @@
 
 import sys
 
+from cliff import command
 import testtools
 
 from stestr import output
 from stestr.repository import util
 from stestr import results
 
 
-def get_cli_help():
-    return "Show the current failures known by the repository"
+class Failing(command.Command):
+    def get_description(self):
+        return "Show the current failures known by the repository"
 
+    def get_parser(self, prog_name):
+        parser = super(Failing, self).get_parser(prog_name)
+        parser.add_argument(
+            "--subunit", action="store_true",
+            default=False, help="Show output as a subunit stream.")
+        parser.add_argument(
+            "--list", action="store_true",
+            default=False, help="Show only a list of failing tests.")
+        return parser
 
-def set_cli_opts(parser):
-    parser.add_argument(
-        "--subunit", action="store_true",
-        default=False, help="Show output as a subunit stream."),
-    parser.add_argument(
-        "--list", action="store_true",
-        default=False, help="Show only a list of failing tests."),
+    def take_action(self, parsed_args):
+        args = parsed_args
+        return failing(repo_type=self.app_args.repo_type,
+                       repo_url=self.app_args.repo_url,
+                       list_tests=args.list, subunit=args.subunit)
 
 
 def _show_subunit(run):
@@ -57,12 +66,6 @@ def _get_id():
         return output_result, summary_result
 
 
-def run(arguments):
-    args = arguments[0]
-    return failing(repo_type=args.repo_type, repo_url=args.repo_url,
-                   list_tests=args.list, subunit=args.subunit)
-
-
 def failing(repo_type='file', repo_url=None, list_tests=False, subunit=False,
             stdout=sys.stdout):
     """Print the failing tests from the most recent run in the repository

stestr/commands/init.py

@@ -14,12 +14,18 @@
 
 import sys
 
+from cliff import command
+
 from stestr.repository import util
 
 
-def run(arguments):
-    args = arguments[0]
-    init(args.repo_type, args.repo_url)
+class Init(command.Command):
+    def take_action(self, parsed_args):
+        init(self.app_args.repo_type, self.app_args.repo_url)
+
+    def get_description(self):
+        help_str = "Create a new repository."
+        return help_str
 
 
 def init(repo_type='file', repo_url=None, stdout=sys.stdout):
@@ -50,12 +56,3 @@ def init(repo_type='file', repo_url=None, stdout=sys.stdout):
                      'Please check if the repository already exists or '
                      'select a different path\n' % repo_path)
         return 1
-
-
-def set_cli_opts(parser):
-    pass
-
-
-def get_cli_help():
-    help_str = "Create a new repository."
-    return help_str

stestr/commands/last.py

@@ -14,47 +14,51 @@
 
 import sys
 
+from cliff import command
+
 from stestr import output
 from stestr.repository import abstract
 from stestr.repository import util
 from stestr import results
 from stestr import subunit_trace
 
 
-def get_cli_help():
-    help_str = """Show the last run loaded into a repository.
-
-    Failing tests are shown on the console and a summary of the run is printed
-    at the end.
-
-    Without --subunit, the process exit code will be non-zero if the test run
-    was not successful. With --subunit, the process exit code is non-zero if
-    the subunit stream could not be generated successfully.
-    """
-    return help_str
-
-
-def set_cli_opts(parser):
-    parser.add_argument(
-        "--subunit", action="store_true",
-        default=False, help="Show output as a subunit stream.")
-    parser.add_argument("--no-subunit-trace", action='store_true',
-                        default=False,
-                        help="Disable output with the subunit-trace output "
-                             "filter")
-    parser.add_argument('--color', action='store_true', default=False,
-                        help='Enable color output in the subunit-trace output,'
-                             ' if subunit-trace output is enabled. (this is '
-                             'the default). If subunit-trace is disable this '
-                             ' does nothing.')
-
-
-def run(arguments):
-    args = arguments[0]
-    pretty_out = not args.no_subunit_trace
-    return last(repo_type=args.repo_type, repo_url=args.repo_url,
-                subunit_out=args.subunit, pretty_out=pretty_out,
-                color=args.color)
+class Last(command.Command):
+    def get_description(self):
+        help_str = """Show the last run loaded into a repository.
+
+        Failing tests are shown on the console and a summary of the run is
+        printed at the end.
+
+        Without --subunit, the process exit code will be non-zero if the test
+        run was not successful. With --subunit, the process exit code is
+        non-zero if the subunit stream could not be generated successfully.
+        """
+        return help_str
+
+    def get_parser(self, prog_name):
+        parser = super(Last, self).get_parser(prog_name)
+        parser.add_argument(
+            "--subunit", action="store_true",
+            default=False, help="Show output as a subunit stream.")
+        parser.add_argument("--no-subunit-trace", action='store_true',
+                            default=False,
+                            help="Disable output with the subunit-trace "
+                            "output filter")
+        parser.add_argument('--color', action='store_true', default=False,
+                            help='Enable color output in the subunit-trace '
+                            'output, if subunit-trace output is enabled. '
+                            '(this is the default). If subunit-trace is '
+                            'disable this does nothing.')
+        return parser
+
+    def take_action(self, parsed_args):
+        args = parsed_args
+        pretty_out = not args.no_subunit_trace
+        return last(repo_type=self.app_args.repo_type,
+                    repo_url=self.app_args.repo_url,
+                    subunit_out=args.subunit, pretty_out=pretty_out,
+                    color=args.color)
 
 
 def last(repo_type='file', repo_url=None, subunit_out=False, pretty_out=True,