core: perform commands on connect

Adds a setting in `core` called `commands_on_connect` based on the updated
`ListAttribute` from sopel-irc#1460. This setting stores a comma separated list
of raw IRC commands (`\`-escaped commas in commands) to execute upon
successful connection to the server. As @dgw put it, "Think ZNC's
perform module, but without the ability to add/remove/rearrange lines
from an IRC query" in sopel-irc#1455.

The commands in the `commands_on_connect` list are executed at the end of
the `startup` procedure. They can also be called by a bot admin with the
`.execute` command.

Note: two `TODO`s were added to adjust docstrings and docs once sopel-irc#1628 is
accepted, since it will change the `ListAttribute` delimiter from
commas to newlines.

Closes sopel-irc#1455

docs/source/configuration.rst

@@ -223,7 +223,47 @@ policy.
    options have been added: ``flood_burst_lines``, ``flood_empty_wait``, and
    ``flood_refill_rate``.
 
+Perform commands on connect
+---------------------------
 
+The bot can be configured to send custom commands upon successful connection to
+the IRC server. This can be used in situations where the bot's built-in
+capabilities are not sufficient, or further automation is desired. The list of
+commands to send is set with :attr:`~CoreSection.commands_on_connect`.
+
+For example, the following configuration:
+
+.. code-block:: ini
+
+    [core]
+    commands_on_connect = PRIVMSG [email protected] :LOGIN MyUserName A$_Strong\,*pasSWord,PRIVMSG IDLEBOT :login IdleUsername idLEPasswoRD
+
+
+will, upon connection:
+
+    1) identify to Undernet services
+    2) login with ``IDLEBOT``
+
+.. important::
+
+    Commas are used to delimit separate commands, so any comma found within a
+    command must be escaped with ``\``. In the example above, the password
+    ``A$_Strong,*pasSWord`` is escaped as ``A$_Strong\,pasSWord`` (note the
+    escaped comma in the middle of the password, but not immediately following,
+    which is delimiting the next command).
+
+    No other text needs to be escaped.
+
+.. 
+    TODO: update this note (and the example config) once #1628 is merged in,
+    changing the delimiter to newlines (from commas).
+
+.. seealso::
+
+    This functionality is analogous to ZNC's ``perform`` module:
+    https://wiki.znc.in/Perform
+
+
 Authentication
 ==============
 

sopel/config/core_section.py

@@ -49,6 +49,10 @@ def configure(config):
         'channels',
         'Enter the channels to connect to at startup, separated by commas.'
     )
+    config.core.configure_setting(
+        'commands_on_connect',
+        'Enter commands to perform on successful connection to server (one per \'?\' prompt).'
+    )
 
 
 class CoreSection(StaticSection):
@@ -347,6 +351,19 @@ def homedir(self):
     capabilities.
     """
 
+    commands_on_connect = ListAttribute('commands_on_connect')
+    r"""A list of commands to perform upon successful connection to IRC server.
+
+    When entered using the config wizard, commas will be escaped automatically.
+    Otherwise, commas must be escaped, e.g.: ``PRIVMSG [email protected]
+    :AUTH my_username MyPassword\,HasAComma@#$%!`` Nothing else needs to be
+    escaped.
+
+    .. versionadded:: 7.0
+    """
+    # TODO: update the docstring above in/after #1628 removes commas as
+    # delimiters for `ListAttribute`s.
+
     pid_dir = FilenameAttribute('pid_dir', directory=True, default='.')
     """The directory in which to put the file Sopel uses to track its process ID.
 

sopel/coretasks.py

@@ -62,6 +62,26 @@ def auth_after_register(bot):
                 auth_target or 'UserServ')
 
 
+def execute_perform(bot):
+    """Execute commands specified to perform on IRC server connect."""
+    if not bot.connection_registered:
+        # How did you even get this command, bot?
+        raise Exception('Bot must be connected to server to perform commands.')
+
+    LOGGER.debug('{} commands to execute:'.format(len(bot.config.core.commands_on_connect)))
+    for i, command in enumerate(bot.config.core.commands_on_connect):
+        LOGGER.debug(command)
+        bot.write((command,))
+
+
+@sopel.module.require_privmsg("This command only works as a private message.")
+@sopel.module.require_admin("This command requires admin privileges.")
+@sopel.module.commands('execute')
+def _execute_perform(bot, trigger):
+    """Execute commands specified to perform on IRC server connect."""
+    execute_perform(bot)
+
+
 @sopel.module.event(events.RPL_WELCOME, events.RPL_LUSERCLIENT)
 @sopel.module.thread(False)
 @sopel.module.unblockable
@@ -111,6 +131,8 @@ def startup(bot, trigger):
         ).format(bot.config.core.help_prefix)
         bot.say(msg, bot.config.core.owner)
 
+    execute_perform(bot)
+
 
 @sopel.module.require_privmsg()
 @sopel.module.require_owner()

test/test_coretasks.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+from sopel import coretasks
 from sopel.module import VOICE, HALFOP, OP, ADMIN, OWNER
 from sopel.tools import Identifier
 from sopel.tests import rawlist
@@ -111,3 +112,27 @@ def test_mode_colon(mockbot, ircfactory):
 
     assert mockbot.channels["#test"].privileges[Identifier("Uvoice")] == VOICE
     assert mockbot.channels["#test"].privileges[Identifier("Uadmin")] == ADMIN
+
+
+def test_execute_perform_raise_not_connected(mockbot):
+    """Ensure bot will not execute ``commands_on_connect`` unless connected."""
+    with pytest.raises(Exception):
+        coretasks.execute_perform(mockbot)
+
+
+def test_execute_perform_send_commands(mockbot):
+    """Ensure bot sends ``commands_on_connect`` as specified in config."""
+    commands = [
+        # Example command for identifying to services on Undernet
+        'PRIVMSG [email protected] :LOGIN my_username my_password',
+        # Set modes on connect
+        'MODE some_nick +Xx',
+        # Oper on connect
+        'OPER oper_username oper_password',
+    ]
+
+    mockbot.config.core.commands_on_connect = commands
+    mockbot.connection_registered = True
+
+    coretasks.execute_perform(mockbot)
+    assert mockbot.backend.message_sent == rawlist(*commands)