Fix IndexError in Typescript completer when querying a subcommand without argument

[micbou]

When typing the command :YcmCompleter without argument in Vim, YCM will return the following error IndexError: list index out of range. This is because the Typescript completer, unlike other completers, does not check if arguments in OnUserCommand is defined.

[puremourning]

Hmm no reviewable.io?

[micbou]

I messed up by editing my comment. This is fixed now.

[vheon]

LGTM

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[puremourning]

The professional in me feels that we should add a test, but LGTM if you don't feel it is worth it :)

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[puremourning]

Reviewed 1 of 1 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

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[micbou]

This is certainly doable. Let me take a shot at it.

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[vheon]

Is doable and it would certainly make sense... but then what about all the other completers?

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[micbou]

I am currently adding tests for all completers. I am wondering if there is a way to get all the supported filetypes by ycmd.
It would be very useful for this kind of tests.

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[vheon]

Wouldn't be better to abstract this into the Completer class?

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[Valloric]

Yes, MOAR TESTS. @micbou I see you've said you're writing further tests. Have I mentioned how I think that's an absolutely brilliant idea? MOAR TESTS FOR TESTORUS, TEH ALMIGHTY TEST GOD. HE WELCOMES YOUR NON-FLAKY OFFERINGS.

@vheon Pulling this out into Completer might be a good idea. I can't imagine how a raw :YcmCompleter call without even a subcommand name could be useful.

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[micbou]

Pulling this out into Completer might be a good idea. I can't imagine how a raw :YcmCompleter call without even a subcommand name could be useful.

This is the new direction I am taking but some changes in the completer API are needed. My current approach is to add a new abstract method GetSubcommandsMap in the Completer class returning a map between the subcommands and the Completer methods to call. This map is then used in DefinedSubcommands and OnUserCommand methods so that Completers don't need to implement them, only the map.

I'll close this PR and send a new one implementing this if you think this is the right approach.

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[vheon]

This is roughly the direction that I had in mind, so for me go ahead to the new PR.

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[micbou]

Closing this in favor of PR #264.

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