cli: add support for aliases in click command groups

requirements-test.txt

+Click
 pytest < 4
 pytest-postgresql
 requests-mock

swh/core/cli/__init__.py

@@ -14,7 +14,25 @@ CONTEXT_SETTINGS = dict(help_option_names=['-h', '--help'])
 logger = logging.getLogger(__name__)
 
 
-@click.group(context_settings=CONTEXT_SETTINGS)
+class AliasedGroup(click.Group):
+    'A simple Group that supports command aliases'
+
+    @property
+    def aliases(self):
+        if not hasattr(self, '_aliases'):
+            self._aliases = {}
+        return self._aliases
+
+    def get_command(self, ctx, cmd_name):
+        return super().get_command(ctx, self.aliases.get(cmd_name, cmd_name))
+
+    def add_alias(self, name, alias):
+        if not isinstance(name, str):
+            name = name.name
+        self.aliases[alias] = name
+
+
+@click.group(context_settings=CONTEXT_SETTINGS, cls=AliasedGroup)
 @click.option('--log-level', '-l', default='INFO',
               type=click.Choice(LOG_LEVEL_NAMES),
               help="Log level (default to INFO)")

swh/core/tests/test_cli.py

+#
+
+import logging
+
+import click
+from click.testing import CliRunner
+
+from swh.core.cli import swh as swhmain
+
+
+help_msg = '''Usage: swh [OPTIONS] COMMAND [ARGS]...
+
+  Command line interface for Software Heritage.
+
+Options:
+  -l, --log-level [NOTSET|DEBUG|INFO|WARNING|ERROR|CRITICAL]
+                                  Log level (default to INFO)
+  -h, --help                      Show this message and exit.
+'''
+
+
+def test_swh_help():
+    runner = CliRunner()
+    result = runner.invoke(swhmain, ['-h'])
+    assert result.exit_code == 0
+    assert result.output == help_msg
+
+    result = runner.invoke(swhmain, ['--help'])
+    assert result.exit_code == 0
+    assert result.output == help_msg
+
+
+def test_command():
+    @swhmain.command(name='test')
+    @click.pass_context
+    def swhtest(ctx):
+        click.echo('Hello SWH!')
+
+    runner = CliRunner()
+    result = runner.invoke(swhmain, ['test'])
+    assert result.exit_code == 0
+    assert result.output.strip() == 'Hello SWH!'
+
+
+def test_loglevel_default(caplog):
+    @swhmain.command(name='test')
+    @click.pass_context
+    def swhtest(ctx):
+        assert logging.root.level == 20
+        click.echo('Hello SWH!')
+
+    runner = CliRunner()
+    result = runner.invoke(swhmain, ['test'])
+    assert result.exit_code == 0
+    print(result.output)
+    assert result.output.strip() == '''Hello SWH!'''
+
+
+def test_loglevel_error(caplog):
+    @swhmain.command(name='test')
+    @click.pass_context
+    def swhtest(ctx):
+        assert logging.root.level == 40
+        click.echo('Hello SWH!')
+
+    runner = CliRunner()
+    result = runner.invoke(swhmain, ['-l', 'ERROR', 'test'])
+    assert result.exit_code == 0
+    assert result.output.strip() == '''Hello SWH!'''
+
+
+def test_loglevel_debug(caplog):
+    @swhmain.command(name='test')
+    @click.pass_context
+    def swhtest(ctx):
+        assert logging.root.level == 10
+        click.echo('Hello SWH!')
+
+    runner = CliRunner()
+    result = runner.invoke(swhmain, ['-l', 'DEBUG', 'test'])
+    assert result.exit_code == 0
+    assert result.output.strip() == '''Hello SWH!'''
+
+
+def test_aliased_command():
+    @swhmain.command(name='canonical-test')
+    @click.pass_context
+    def swhtest(ctx):
+        'A test command.'
+        click.echo('Hello SWH!')
+    swhmain.add_alias(swhtest, 'othername')
+
+    runner = CliRunner()
+
+    # check we have only 'canonical-test' listed in the usage help msg
+    result = runner.invoke(swhmain, ['-h'])
+    assert result.exit_code == 0
+    assert 'canonical-test  A test command.' in result.output
+    assert 'othername' not in result.output
+
+    # check we can execute the cmd with 'canonical-test'
+    result = runner.invoke(swhmain, ['canonical-test'])
+    assert result.exit_code == 0
+    assert result.output.strip() == '''Hello SWH!'''
+
+    # check we can also execute the cmd with the alias 'othername'
+    result = runner.invoke(swhmain, ['othername'])
+    assert result.exit_code == 0
+    assert result.output.strip() == '''Hello SWH!'''