Changed HelpCommand to raise CommandError instead of InstalationError, when no command is found. It returns status SUCCESS (0) if find command or no command is specified.

pip/commands/help.py

@@ -1,8 +1,12 @@
 from pip.basecommand import Command, command_dict, load_all_commands
-from pip.exceptions import InstallationError
+from pip.exceptions import CommandError
 from pip.baseparser import parser
 
 
+ERROR = 1
+SUCCESS = 0
+
+
 class HelpCommand(Command):
     name = 'help'
     usage = '%prog'
@@ -14,10 +18,10 @@ class HelpCommand(Command):
             ## FIXME: handle errors better here
             command = args[0]
             if command not in command_dict:
-                raise InstallationError('No command with the name: %s' % command)
+                raise CommandError('No command with the name: %s' % command)
             command = command_dict[command]
             command.parser.print_help()
-            return
+            return SUCCESS
         parser.print_help()
         print('\nCommands available:')
         commands = list(set(command_dict.values()))
@@ -26,6 +30,6 @@ class HelpCommand(Command):
             if command.hidden:
                 continue
             print('  %s: %s' % (command.name, command.summary))
-
+        return SUCCESS
 
 HelpCommand()

tests/test_help.py

@@ -0,0 +1,62 @@
+from pip.exceptions import CommandError
+from pip.commands.help import (HelpCommand,
+                               SUCCESS,
+                               ERROR,)
+from mock import Mock
+from nose.tools import assert_raises
+from tests.test_pip import run_pip, reset_env
+
+
+def test_run_method_should_return_sucess_when_finds_command_name():
+    """
+    Test HelpCommand.run for existing command
+    """
+    options_mock = Mock()
+    args = ('freeze',)
+    help_cmd = HelpCommand()
+    status = help_cmd.run(options_mock, args)
+    assert status == SUCCESS
+
+def test_run_method_should_return_sucess_when_command_name_not_specified():
+    """
+    Test HelpCommand.run when there are no args
+    """
+    options_mock = Mock()
+    args = ()
+    help_cmd = HelpCommand()
+    status = help_cmd.run(options_mock, args)
+    assert status == SUCCESS
+
+def test_run_method_should_raise_command_error_when_command_does_not_exist():
+    """
+    Test HelpCommand.run for non-existing command
+    """
+    options_mock = Mock()
+    args = ('mycommand',)
+    help_cmd = HelpCommand()
+    assert_raises(CommandError, help_cmd.run, options_mock, args)
+
+def test_help_command_should_exit_status_ok_when_command_exists():
+    """
+    Test `help` command for existing command
+    """
+    reset_env()
+    result = run_pip('help', 'freeze')
+    assert result.returncode == SUCCESS
+
+def test_help_command_should_exit_status_ok_when_no_command_is_specified():
+    """
+    Test `help` command for no command
+    """
+    reset_env()
+    result = run_pip('help')
+    assert result.returncode == SUCCESS
+
+def test_help_command_should_exit_status_error_when_command_does_not_exist():
+    """
+    Test `help` command for non-existing command
+    """
+    reset_env()
+    result = run_pip('help', 'mycommand', expect_error=True)
+    assert result.returncode == ERROR
+