Auto-suggest should never pop up after case statements

[ffxsam]

• I have searched through existing issues
• I have read through docs
• I have read FAQ

Info

• Platform: macOS 10.13.3
• Vetur version: 0.11.7
• VS Code version: 1.20.1

Problem

Auto suggest pops up every time after case (and default) statements. This is highly annoying as we have to hit ESC after every single case statement.

Reproducible Case

1. Open .vue file
2. Navigate to script block
3. Create a switch block, and start entering case statements

[HerringtonDarkholme]

Sadly vscode only supports one set of completion trigger:

https://github.com/vuejs/vetur/blob/master/server/src/vueServerMain.ts#L58

We need to add : in completion triggers for template completion.

[ffxsam]

@HerringtonDarkholme I don't understand. This autocompletion for case statements doesn't happen in regular JS files. Could you elaborate on why this happens in Vetur?

[octref]

This happens because we use a superset of completion triggers for html/css/js in Vetur. Completion triggers are like . (for js properties), < (for html tags). We added : for :foo completions in Vue template.

I'll open an upstream issue to track this.

[ffxsam]

Thanks! Makes sense that the : completion trigger would only work in the <template> block and not the <script> block.. but it sounds like a VS Code limitation.

[HerringtonDarkholme]

That's not possible in VSCode now. And it is not supported in most editors as far as I know. Few editors place mixed language file in the first place.

On the other hand, dynamically changing completion triggers isn't the most sensible choice. The only use case I can see is mixed language.

So the problem is better modeled as how to support mixed language in editors. Say, JS in HTML, SQL in PHP. Other than triggering completion, there are other issues related to mixed language. For example, how to count consecutive characters as one word, and emmet expansion in JS/html/css, comment toggling. One direct way to detect language is by syntax highlighting.

For @ffxsam 's issue, I suggest you to separate another file for media processing, if they are not involved in UI logic. If they are, a hash table is probably better than switch case.

Prior art:

https://github.com/purcell/mmm-mode
https://github.com/Shougo/context_filetype.vim/blob/master/doc/context_filetype.txt

[octref]

Umm this naive way of doing it seems to be working:

connection.onCompletion(textDocumentPosition => {
  const document = documents.get(textDocumentPosition.textDocument.uri);
  const offset = document.offsetAt(
    Position.create(textDocumentPosition.position.line, textDocumentPosition.position.character - 1)
  );
  const triggerChar = document.getText()[offset];
  if (triggerChar === ':') {
    return { isIncomplete: false, items: [] };
  }
  return vls.doComplete(document, textDocumentPosition.position);
});

I can put it in js/ts mode to return empty suggestions when trigger characters aren't js/ts trigger characters.

[octref]

When we upgrade to LS 4.0 we can use the CompletionContext, see https://microsoft.github.io/language-server-protocol/specification#completion-request-leftwards_arrow_with_hook