Adding a textEdit to a completionItem from a language server causes VSCode to display 'No suggestions.'

[rictic]

Does this issue occur when all extensions are disabled?: N/A

• VS Code Version: v1.82.2
• OS Version: macOS Venture 13.0.1 (22A400)

Steps to Reproduce:

1. Take a working language server that is returning simple CompletionItems, with with just a label and kind, with no completion resolver.
2. Add the textEdit field to those CompletionItems, to better control identifier boundaries.
3. Observe that VSCode no longer displays your completions.

Commentary:

I suspect that there are more constraints on using textEdit than are documented at https://microsoft.github.io/language-server-protocol/specifications/specification-3-14/#textDocument_completion.

Screenshot showing VSCode displaying no completion items, as well as the textDocument/completion response sent from the language server, where the completions were requested.

[jrieken]

A completion item provider is invoked, returns completions but they don't show up! 😕 What's the issue? Filtering! Filtering compares completions with a prefix and hides those that don't match.

Example

• trigger completions here: say.he| (| is the cursor)
• provider returns abc, help, hood
• the editor takes the he-prefix and scores it against abc, help, and hood.
• scoring yields these result:
  • abc - no match, don't show
  • help - good match, show
  • hood - no match, only h occurs, don't show
• editor shows help suggestion, does not show abc and hood suggestion

Extensions Rule!

The above sample was using "defaults" to determine the prefix and the filter criteria.

• prefix: each completion can define its very own prefix via vscode.CompletionItem#range. Taking the example above, valid prefixes can be say.he or .he or (the empty string). Any range is valid as long as it includes the cursor position and is single line only.
• filter: each completion can define what string to use when filtering. The default is the label but via vscode.CompletionItem#filterText any string can be defined

When to use what? It depends on the language, its word definition, and if you control/understand the word definition or not. The defaults usually work well enough but some languages might use a non-intuitive word definition, or completions span multiple words, or completions include non-word character etc. In all those cases the range-property should be used.

[rictic]

range.replacing looks very promising, I'll give that a try instead of textEdit.

Is it expected that adding a textEdit would change filtering such that a completion that was being shown is no longer? That's what I'm seeing. The user's cursor is at bui| and the first completion is:

{
  "label": "build", 
  "kind": 9, 
  "textEdit": {...}
}

Without that textEdit, the completion is displayed. If textEdit is deprecated and no longer supported that's fine, range.replacing looks like a fine replacement, I just didn't see that documented anywhere.

[rictic]

Oh I see now in the VSCode typings that textEdit is marked as deprecated. I was looking at the LSP docs. Does VSCode log a warning anywhere when it filters out a completion item with a textEdit?

[rictic]

Hm, I don't see range in the LSP docs, but a textEdit can be an InsertReplaceEdit, I'll try that.

[rictic]

Giving an InsertReplaceEdit of:

{
  "newText": "build",
  "replace": {/* range to replace the entire string literal */},
  "insert": {/* the same range to replace the entire string literal */},
}

gives the same result, No suggestions.

[vscodenpa]

We closed this issue because it is a question about using VS Code rather than an issue or feature request. Please search for help on StackOverflow, where the community has already answered thousands of similar questions. You may find their guide on asking a new question helpful if your question has not already been asked. See also our issue reporting guidelines.

Happy Coding!

[jrieken]

I am closing this as question, please follow up with #194580 (comment). It's vital that the text that's "selected" by the ranges matches the filterText