Exceptions from executing commands with wrong arguments cannot be caught

[evandrocoan]

Sublime Text Python's Interpreter for packages is not catching an exception throwed by sublime.py

This was migrated from http://stackoverflow.com/questions/39461428/how-to-catch-sublime-text-exceptions-on-their-python-interpreter.

I am trying to catch this exception:

    try:

        print( 'RUNNING' )
        sublime.active_window().run_command( "side_bar_update_sync" )
        isNotSyncedSideBarEnabled = False
        print( 'RUNNING THIS' )

    except BaseException:

        isNotSyncedSideBarEnabled = True
        print( 'RUNNING THIS ALSO' )

But when it is ran, it just does not catches it. Does not matter if I try it within TypeError, Exception or BaseException classes. This below is the full exception output.

reloading plugin SublimeDefaultSyntax.default_syntax
READ_PREF_ASYNC!!!!
    updateIsSyncedSideBarEnabled!!!!
RUNNING
Traceback (most recent call last):
  File "D:\User\Dropbox\Applications\SoftwareVersioning\SublimeText\sublime_plugin.py", line 538, in run_
    return self.run()
TypeError: run() missing 1 required positional argument: 'enable'
RUNNING THIS
isNotSyncedSideBarEnabled: False

The problem is, the python cannot catch the exception throwed by run_command( "side_bar_update_sync" ). The exception catching for errors like trying to call self.view, when there is no self passed by, are working fine. This is the full code:

def plugin_loaded():

    global isNotSyncedSideBarEnabled

    packageControlSettings = sublime.load_settings('Package Control.sublime-settings')
    userSettings           = sublime.load_settings('Preferences.sublime-settings')

    def updateIsSyncedSideBarEnabled():

        global isNotSyncedSideBarEnabled

        print('    updateIsSyncedSideBarEnabled!!!!')
        sublime.active_window().run_command( "reveal_in_side_bar" )

        try:

            print( 'RUNNING' )
            sublime.active_window().run_command( "side_bar_update_sync" )
            isNotSyncedSideBarEnabled = False
            print( 'RUNNING THIS' )

        except BaseException:

            isNotSyncedSideBarEnabled = True
            print( 'RUNNING THIS ALSO' )

        print( 'isNotSyncedSideBarEnabled: ' + str( isNotSyncedSideBarEnabled ) )



    def read_pref_async():

        print('READ_PREF_ASYNC!!!!')
        updateIsSyncedSideBarEnabled()


    def read_pref_package():

        print('READ_PREF_PACKAGE!!!!')
        updateIsSyncedSideBarEnabled()


    def read_pref_preferences():

        print('READ_PREF_PREFERENCES!!!!')
        updateIsSyncedSideBarEnabled()


    # read initial setting, after all packages being loaded
    sublime.set_timeout_async( read_pref_async, 1000 )

    # listen for changes
    packageControlSettings.add_on_change( "Package Control", read_pref_package )
    userSettings.add_on_change( "Preferences", read_pref_preferences )

    #print( userSettings.get( "ignored_packages" ) )
    #print( packageControlSettings.get( "installed_packages" ) )

This discussion may be followed by this Sublime Text Forum's thread: https://forum.sublimetext.com/t/how-to-add-remove-a-default-menu-entry-when-a-x-package-is-isnt-enabled-installed/22753?u=addons_zz

This are the lines from the file showed on the exception:

532 class ApplicationCommand(Command):
533     def run_(self, edit_token, args):
534         args = self.filter_args(args)
535         if args:
536             return self.run(**args)
537         else:
538             return self.run()
539
540    def run(self):
541        pass1
542
543 ... other classes

---

Environment

• Operating system and version:
  • Windows 10 ...
  • Mac OS ...
  • Linux ...
• Sublime Text:
  • Build 3114

[FichteFoll]

Here's a smaller repro:

import sublime_plugin

class TestCommandCommand(sublime_plugin.TextCommand):
    def run(self, edit):
        try:
            ret = self.view.window().run_command("toggle_comment", {"fuck": "no"})
        except:
            print("an exception")
        else:
            print(ret)

Console:

reloading plugin User.test
command: test_command
Traceback (most recent call last):
  File "C:\Program Files\Sublime Text 3\sublime_plugin.py", line 792, in run_
    return self.run(edit, **args)
TypeError: run() got an unexpected keyword argument 'fuck'
None

Needless to say, this only happens for Python commands and not internal commands since those do not error at all.

[wbond]

I tend to doubt this will really change. When you try to run a command, the request is sent to the sublime_text executable. If it is an internal command, it is executed in C++. If it is implemented in Python, sublime_text sends a message to plugin_host to execute the command. If there is an error in running the command, there is no way to throw the exception back through sublime_text and then back into plugin_host.

It will also be made even further more complicated by future changes to how the plugin_host works.

[FichteFoll]

While catching the exact exception may not be important, what about giving run_command a boolean return value indicating whether the command was executed properly? Currently you receive absolutely zero feedback from your code whether a command did its work, failed somewhere or outright doesn't exist (I believe we had an issue for that but can't find it).