After some discussion about how to handle insert and filter text
(https://github.com/microsoft/vscode-languageserver-node/issues/488), it
seems that it is better practice to overwrite the prefix in completion
items, rather than trimming the prefix from the insert text.
Change-Id: I7c794b4b1d4518af31e7318a283aa3681a0cf66a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/176958
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>