Add subcommand alias mechanism

Author: McSinyx

news/8130.feature

@@ -0,0 +1,2 @@
+Add aliases 'add' and 'remove' aliases for 'install' and 'uninstall',
+respectively.

src/pip/_internal/cli/autocompletion.py

@@ -7,7 +7,7 @@
 from itertools import chain
 
 from pip._internal.cli.main_parser import create_main_parser
-from pip._internal.commands import commands_dict, create_command
+from pip._internal.commands import create_command, subcommands_set
 from pip._internal.utils.misc import get_installed_distributions
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
@@ -30,7 +30,7 @@ def autocomplete():
         current = ''
 
     parser = create_main_parser()
-    subcommands = list(commands_dict)
+    subcommands = list(subcommands_set)
     options = []
 
     # subcommand

src/pip/_internal/cli/main_parser.py

@@ -9,8 +9,11 @@
     ConfigOptionParser,
     UpdatingDefaultsHelpFormatter,
 )
-from pip._internal.commands import commands_dict, get_similar_commands
-from pip._internal.exceptions import CommandError
+from pip._internal.commands import (
+    aliases_of_commands,
+    check_subcommand,
+    commands_dict,
+)
 from pip._internal.utils.misc import get_pip_version, get_prog
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
@@ -47,10 +50,10 @@ def create_main_parser():
     parser.main = True  # type: ignore
 
     # create command listing for description
-    description = [''] + [
-        '{name:27} {command_info.summary}'.format(**locals())
-        for name, command_info in commands_dict.items()
-    ]
+    description = ['']
+    for name, info in commands_dict.items():
+        names = ', '.join(aliases_of_commands[name])
+        description.append('{:27} {.summary}'.format(names, info))
     parser.description = '\n'.join(description)
 
     return parser
@@ -82,16 +85,7 @@ def parse_command(args):
 
     # the subcommand name
     cmd_name = args_else[0]
-
-    if cmd_name not in commands_dict:
-        guess = get_similar_commands(cmd_name)
-
-        msg = ['unknown command "{}"'.format(cmd_name)]
-        if guess:
-            msg.append('maybe you meant "{}"'.format(guess))
-
-        raise CommandError(' - '.join(msg))
-
+    check_subcommand(cmd_name)
     # all the args without the subcommand
     cmd_args = args[:]
     cmd_args.remove(cmd_name)

src/pip/_internal/commands/__init__.py

@@ -14,10 +14,11 @@
 import importlib
 from collections import OrderedDict, namedtuple
 
+from pip._internal.exceptions import CommandError
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any
+    from typing import Any, Dict, List, Set
     from pip._internal.cli.base_command import Command
 
 
@@ -94,13 +95,27 @@
     )),
 ])  # type: OrderedDict[str, CommandInfo]
 
+aliases_dict = {
+    'add': 'install',
+    'remove': 'uninstall',
+}  # type: Dict[str, str]
+aliases_of_commands = {
+    name: [name] for name in commands_dict}  # type: Dict[str, List[str]]
+for alias, name in aliases_dict.items():
+    aliases_of_commands[name].append(alias)
+subcommands_set = {cmd for aliases in aliases_of_commands.values()
+                   for cmd in aliases}  # type: Set[str]
+
 
 def create_command(name, **kwargs):
     # type: (str, **Any) -> Command
     """
     Create an instance of the Command class with the given name.
     """
-    module_path, class_name, summary = commands_dict[name]
+    try:
+        module_path, class_name, summary = commands_dict[name]
+    except KeyError:
+        module_path, class_name, summary = commands_dict[aliases_dict[name]]
     module = importlib.import_module(module_path)
     command_class = getattr(module, class_name)
     command = command_class(name=name, summary=summary, **kwargs)
@@ -114,9 +129,20 @@ def get_similar_commands(name):
 
     name = name.lower()
 
-    close_commands = get_close_matches(name, commands_dict.keys())
+    close_commands = get_close_matches(name, subcommands_set)
 
     if close_commands:
         return close_commands[0]
     else:
         return False
+
+
+def check_subcommand(name):
+    # type: (str) -> None
+    """Raise CommandError if the given subcommand not found."""
+    if name not in aliases_dict and name not in commands_dict:
+        guess = get_similar_commands(name)
+        msg = 'unknown command "{}"'.format(name)
+        if guess:
+            msg += ' - maybe you meant "{}"'.format(guess)
+        raise CommandError(msg)

src/pip/_internal/commands/help.py

@@ -5,7 +5,6 @@
 
 from pip._internal.cli.base_command import Command
 from pip._internal.cli.status_codes import SUCCESS
-from pip._internal.exceptions import CommandError
 
 
 class HelpCommand(Command):
@@ -16,25 +15,15 @@ class HelpCommand(Command):
     ignore_require_venv = True
 
     def run(self, options, args):
-        from pip._internal.commands import (
-            commands_dict, create_command, get_similar_commands,
-        )
+        from pip._internal.commands import check_subcommand, create_command
 
         try:
             # 'pip help' with no args is handled by pip.__init__.parseopt()
             cmd_name = args[0]  # the command we need help for
         except IndexError:
             return SUCCESS
 
-        if cmd_name not in commands_dict:
-            guess = get_similar_commands(cmd_name)
-
-            msg = ['unknown command "{}"'.format(cmd_name)]
-            if guess:
-                msg.append('maybe you meant "{}"'.format(guess))
-
-            raise CommandError(' - '.join(msg))
-
+        check_subcommand(cmd_name)
         command = create_command(cmd_name)
         command.parser.print_help()
 

tests/functional/test_help.py

@@ -2,7 +2,7 @@
 from mock import Mock
 
 from pip._internal.cli.base_command import ERROR, SUCCESS
-from pip._internal.commands import commands_dict, create_command
+from pip._internal.commands import create_command, subcommands_set
 from pip._internal.exceptions import CommandError
 
 
@@ -79,7 +79,7 @@ def test_help_commands_equally_functional(in_memory_pip):
     assert sum(ret) == 0, 'exit codes of: ' + msg
     assert all(len(o) > 0 for o in out)
 
-    for name in commands_dict:
+    for name in subcommands_set:
         assert (
             in_memory_pip.pip('help', name).stdout ==
             in_memory_pip.pip(name, '--help').stdout != ""

tests/lib/options_helpers.py

@@ -5,7 +5,7 @@
 
 from pip._internal.cli import cmdoptions
 from pip._internal.cli.base_command import Command
-from pip._internal.commands import CommandInfo, commands_dict
+from pip._internal.commands import CommandInfo, commands_dict, subcommands_set
 from tests.lib.configuration_helpers import reset_os_environ
 
 
@@ -27,7 +27,9 @@ def setup(self):
         commands_dict['fake'] = CommandInfo(
             'tests.lib.options_helpers', 'FakeCommand', 'fake summary',
         )
+        subcommands_set.add('fake')
 
     def teardown(self):
         reset_os_environ(self.environ_before)
         commands_dict.pop('fake')
+        subcommands_set.remove('fake')

tests/unit/test_commands.py

@@ -6,7 +6,12 @@
     RequirementCommand,
     SessionCommandMixin,
 )
-from pip._internal.commands import commands_dict, create_command
+from pip._internal.commands import (
+    aliases_dict,
+    commands_dict,
+    create_command,
+    subcommands_set,
+)
 
 # These are the expected names of the commands whose classes inherit from
 # IndexGroupCommand.
@@ -33,12 +38,16 @@ def test_commands_dict__order():
     assert names[-1] == 'help'
 
 
-@pytest.mark.parametrize('name', list(commands_dict))
+@pytest.mark.parametrize('name', subcommands_set)
 def test_create_command(name):
     """Test creating an instance of each available command."""
     command = create_command(name)
     assert command.name == name
-    assert command.summary == commands_dict[name].summary
+    try:
+        summary = commands_dict[name]
+    except KeyError:
+        summary = commands_dict[aliases_dict[name]]
+    assert command.summary == summary
 
 
 def test_session_commands():