Brigadier completion is broken on Minecraft 1.13.2

[0dinD]

Preconditions:

• Use cloud-bukkit or cloud-paper on Minecraft 1.13.2, with commodore
• Call BukkitCommandManager#registerBrigadier()
• Begin typing a command that will trigger completions (in my case, it was an org.bukkit.World argument)

When the completions are to be shown, the client gets disconnected with the following message:

And indeed, that method does not exist on Minecraft 1.13.2, which uses Brigadier 1.0.14 as per https://launchermeta.mojang.com/v1/packages/1f439c21fee6a7816356c40a6194d064d1f44baa/1.13.2.json.

Or well, it does exist, but the return type is different, which is the cause of this issue. It was changed here: Mojang/brigadier@107b852#diff-18472a62b649fb2b670a39478656c3a7f56e5457db300b7dc1a8fdac11e13c55R122-R130

That change made it into Brigadier 1.0.17, which is used on Minecraft 1.14.4+ as per https://launchermeta.mojang.com/v1/packages/8f81523cd2c2fdaf9c37431fceb0a446dbe71ed5/1.14.4.json.

This issue has not always been present, usage of the CommandContext#getNodes() method was introduced in cloud-brigadier here: f16cafd#diff-a1afbb0e9ce645c8eb5bcfc7801fb95495ecff3231bfd7a725ded1f51fde39adR632-R634

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These are some possible resolutions to the issue that come to my mind:

1. Drop the usage of the CommandContext#getNodes() method.
2. Use reflection or similar to support Brigadier 1.0.14. It looks like getNodes() returns essentially the same information on both versions, it's just the return type that changed.
3. Drop support for 1.13, and make sure that CommandManager#hasCapability(CloudBukkitCapabilities.BRIGADIER) returns false on Minecraft 1.13.

I don't know enough about the code to know which solution makes the most sense. Plugin authors can also work around the issue by checking the Minecraft version and skipping the brigadier registration on 1.13.

[jpenilla]

Should be resolved in 1.8.0-SNAPSHOT, testing appreciated

[0dinD]

Works like a charm, thanks for the quick fix!