Typescript syntax highlighting breaks under a set of conditions

[khvorov45]

Describe the bug

Example of wrong highlighting (bottom 3 lines)

Most subsequent code would be highlighted in yellow as if it was all a string.

The set of conditions required for this is (images contain (mostly) correct highlighting when the corresponding condition is removed):

3+ fields in an object argument

Generic use in the return type (highlight still questionable without it)

Template string use (highlight still questionable without it)

No commas in the types for the object fields (main issue?)

Version & OS

OS: Linux Mint 20
Desktop: 2.5.7-linux1

Files

Code in screenshots

[shiftkey]

@khvorov45 thanks for the report. We're using Codemirror and it's syntax highlighting support in GitHub Desktop so maybe something's changed in there.

If this is reproducible on macOS or Windows I think this should be reported on the main repository, as I suspect this isn't a Linux-specific issue at first glance. I'll have a look at reproducing this later in the week when I have some bandwidth.

[shiftkey]

Tested this out in macOS with the latest beta release (2.6.1-beta3) and I see the same problem as you:

No commas in the types for the object fields (main issue?)

There's a sandbox mode for Typescript you can test here https://codemirror.net/mode/javascript/typescript.html which also shows the same behaviour, so I think you're on the right track.

I can't spot a report in the Codemirror project for this specific issue, but there is a pending update to codemirror under app/package.json (from 5.49.2 to 5.58.3) that might address this.

EDIT: because we can reproduce this on the Codemirror sandbox, that suggests the latest version of Codemirror doesn't handle this case. That's the place where this needs to be fixed to work correctly in GitHub Desktop.

[khvorov45]

Submitted an issue to Codemirror

[khvorov45]

Fixed in Codemirror 5.59.0 (not documented in the release notes).