LSC is not always debouncing

[bluz71]

Hello Nate,

I have journeyed down a debounce rabbit hole.

LSC does debounce, but not always. My query is about the times LSC does not appear to debounce whilst a user is typing content.

I have been experimenting with the Ruby language server, Solargraph, and this example Ruby sample file:

class FooBar
  def initialize
    @abc = "abc"
    @hello = "hello"
    @help = "help"
  end

  def baz
    <<INSERT-CONTENT-HERE>>
  end
end

foo = Foobar.new

I bumped up the LSC 500ms debounce timer to 2 seconds during my testing.

At the same time I setup Solargraph to real time log input and output events as noted in the LSC debug documentation.

At the above <<INSERT-CONTENT-HERE>> position if I type FooBarFooBarFooBarFooBarFooBar then LSC debounces textDocument/didChange requests. Noting that FooBar matches the class name in the buffer. Only one textDocument/didChange event is sent, and no textDocument/completion event (after the Foo prefix is sent, noting LSC by default waits until the third character).

If instead I type BarFooBarFooBarFooBarFooBarFoo then LSC sends a textDocument/didChange and textDocument/completion pairs after every character typed (from the third character onwards). Noting that Bar prefix does not match anything.

It seems if a three character prefix produces completion matches then debouncing happens for characters typed after the prefix. If the prefix does not produce completion matches then LSC sends a textDocument/didChange and textDocument/completion pair for every typed character after the prefix.

My expectation is that debouncing should occur in both instances.

Best regards.