The given key 'insertFinalNewline' was not present in the dictionary

[shenglol]

Got this error when requesting document formatting with no insertFinalNewline set in FormattingOptions:

Internal Error - System.Collections.Generic.KeyNotFoundException: The given key 'insertFinalNewline' was not present in the dictionary.

According to the LSP docs trimTrailingWhitespace, insertFinalNewline and trimFinalNewlines are optional, however it seems the OmniSharp implementation just assumes they are always in the dictionary? Should we check their existence before accessing the keys?

csharp-language-server-protocol/src/Protocol/Models/FormattingOptions.cs

Line 40 in 6371386

get => this["trimTrailingWhitespace"].IsBool ? this["trimTrailingWhitespace"].Bool : false;

[david-driscoll]

looks like a bug, it should be using TryGetValue instead.