Surprising autocomplete with string literal

[danvk]

Describe the bug

I was working on this Advent of Code problem and had an odd bug where I printed #. instead of . which gave me a wrong answer. Oh well, probably fat fingered it.

For part two of the problem, I spent quite a while debugging my incorrect solution before eventually realizing I'd made the exact same mistake a second time. Now I was suspicious. It turns out it was the VSCode Deno extension's fault. It was quietly changing '.' to '#.' as I typed the former. That string ('#.') never appears on its own elsewhere in my code, only as a substring of larger strings:

Screen.Recording.2022-12-10.at.11.01.05.AM.mov

To Reproduce

1. Open up this file in VS Code https://github.com/danvk/aoc2022/blob/49917882eb0f2b64f407857eab052c1f674e3551/warmup/y2018day12/y2018day12.ts#L32
2. Rewrite the '.' by typing ' then . then ' as in the video
3. Scratch your head as the Deno extension changes the string to '#.'.

The surprising change happens when I type the . character.

Expected behavior

When I type '.', I would expect to get that string in my source code, rather than a different string.

For comparison, the TypeScript playground does exactly what I expect with this same source code.

Screenshots

Here's the video again, where I type ' then . then ':

Screen.Recording.2022-12-10.at.11.01.05.AM.mov

Versions

• vscode: 1.72.1
• deno: deno 1.28.3 (release, aarch64-apple-darwin) / v8 10.9.194.5 / typescript 4.8.3
• extension: v3.14.1

[dsherret]

Thanks for reporting these issues, Dan. The language server has some rough edges (especially related to node compatibility). We're planning on prioritizing fixes for it in the new year.

[bartlomieju]

I'm working on a fix for this problem.