TypeScript Syntax highlighting is wrong when comments are inside type definition

Type: Bug

Syntax highlighting in TypeScript is wrong in cases where there are comments in the type.

type MyType =
  | null //
  | undefined;

let test:
  | null //
  | undefined;

let test2:
  | "a" //
  | null;

let a: null | "a"; //

let b: //
  null | "a";

let c: "a" | null;

let d:
  | "a" //
  | null;

let e:
  | "a" //
  | null
  | undefined;

let f:
  | "a"
  | null //
  | undefined;

let g:
  | "a"
  | null
  //
  | undefined;

type A = {
  a: null | undefined;
  b:
  | null //
  | undefined;
  c: //
  null | undefined;
  d:
  | "a" //
  | undefined
  | null //
  | true;
};

Below is a screenshot of the same code in VSCode and in the TypeScript playground. The typescript playground textmate grammar seems to handle all these cases correctly, but the VSCode one doesn't. Please note that there are some differences in the theme (property names are blue, keywords in type definitions are green), but the VSCode grammar is inconsistent with itself.

Keywords: Textmate Grammar

VS Code version: Code - Insiders 1.82.0-insider (d62534a60f7eb4280bcbee66bbd84a2e15f13765, 2023-08-10T05:33:20.243Z) OS version: Windows_NT x64 10.0.22000 Modes: Remote OS version: Linux x64 5.15.90.1-microsoft-standard-WSL2 Remote OS version: Linux x64 5.15.90.1-microsoft-standard-WSL2

System Info

|Item|Value| |---|---| |CPUs|AMD Ryzen 9 5900X 12-Core Processor (24 x 4200)| |GPU Status|2d_canvas: enabled
canvas_oop_rasterization: enabled_on
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
video_decode: enabled
video_encode: enabled
vulkan: disabled_off
webgl: enabled
webgl2: enabled
webgpu: enabled| |Load (avg)|undefined| |Memory (System)|31.92GB (5.45GB free)| |Process Argv|--crash-reporter-id 68f6fdac-c31a-432d-8c54-337698814abd| |Screen Reader|no| |VM|0%| |Item|Value| |---|---| |Remote|WSL: Ubuntu| |OS|Linux x64 5.15.90.1-microsoft-standard-WSL2| |CPUs|AMD Ryzen 9 5900X 12-Core Processor (24 x 4200)| |Memory (System)|15.58GB (5.49GB free)| |VM|0%| |Item|Value| |---|---| |Remote|WSL: Ubuntu| |OS|Linux x64 5.15.90.1-microsoft-standard-WSL2| |CPUs|AMD Ryzen 9 5900X 12-Core Processor (24 x 4200)| |Memory (System)|15.58GB (5.49GB free)| |VM|0%|

Extensions: none

A/B Experiments

``` vsliv695:30137379 vsins829:30139715 vsliv368:30146709 vsreu685:30147344 python383cf:30185419 vspor879:30202332 vspor708:30202333 vspor363:30204092 vstes627:30244334 vslsvsres303:30308271 pythontb:30258533 vsc_aacf:30263846 pythonptprofiler:30281269 vshan820:30294714 vscod805:30301674 bridge0708:30335490 bridge0723:30353136 vsaa593:30376534 pythonvs932:30404738 py29gd2263:30784851 vsclangdf:30492506 c4g48928:30535728 dsvsc012:30540252 pynewext54:30618038 2i9eh265:30646982 showlangstatbar:30737417 24365598:30687740 pythonfmttext:30716741 fixshowwlkth:30771523 showindicator:30805243 pythongtdpath:30726887 i26e3531:30792625 gsofa:30797620 welcomedialog:30812478 pythonnosmt12:30779711 pythonidxpt:30768918 pythonnoceb:30776497 copilotsettingt:30808721 dsvsc013:30777762 dsvsc014:30777825 diffeditorv2:30786206 pythonmhint1:30815193 ```

microsoft / TypeScript-TmLanguage

TypeScript Syntax highlighting is wrong when comments are inside type definition #989