Typescript error

[matvejs16]

Type: Bug

Getting typescript error on "event" variable in events.on method:

Argument of type 'keyof IClientEvents' is not assignable to parameter of type 'string'.
  Type 'number' is not assignable to type 'string'.ts(2345)

Steps to reproduce:

1. Create Typescript file (.ts)
2. Paste code:

   
   type IClientEvents = {
   [event: string]: (...args: any[]) => void;
   testClient: (arg: string) => void;
   testClient2: (arg: string) => void;
   }

const customEvents: Map<string, Function[]> = new Map(); const events = { on(event: T, callback: IClientEvents[T]) { if (!customEvents.has(event)) customEvents.set(event, []); // getting error on "event" customEvents.get(event)?.push(callback); } }

VS Code version: Code - Insiders 1.87.0-insider (00124e9e5830e3efc897db71c781899f8a676295, 2024-02-16T16:33:57.085Z)
OS version: Windows_NT x64 10.0.22631
Modes:

<details>
<summary>System Info</summary>

|Item|Value|
|---|---|
|CPUs|11th Gen Intel(R) Core(TM) i7-11700K @ 3.60GHz (16 x 3600)|
|GPU Status|2d_canvas: enabled<br>canvas_oop_rasterization: enabled_on<br>direct_rendering_display_compositor: disabled_off_ok<br>gpu_compositing: enabled<br>multiple_raster_threads: enabled_on<br>opengl: enabled_on<br>rasterization: enabled<br>raw_draw: disabled_off_ok<br>skia_graphite: disabled_off<br>video_decode: enabled<br>video_encode: enabled<br>vulkan: disabled_off<br>webgl: enabled<br>webgl2: enabled<br>webgpu: enabled|
|Load (avg)|undefined|
|Memory (System)|31.87GB (22.95GB free)|
|Process Argv|E:\\Coding Scripts\\Vue\\SocketIO-TS-Module-Test --crash-reporter-id c1f0a67e-8694-4f1d-abf8-047a7ae97861|
|Screen Reader|no|
|VM|0%|
</details><details><summary>Extensions (69)</summary>

Extension|Author (truncated)|Version
---|---|---
vscode-css-formatter|aes|1.0.2
TabOut|alb|0.2.2
Bookmarks|ale|13.4.2
vscode-color|ans|0.4.5
ejs-snippets-and-color-highlighting|Ayu|0.0.5
vscode-intelephense-client|bme|1.10.2
npm-intellisense|chr|1.4.5
path-intellisense|chr|2.8.5
format-json|Cle|1.0.3
vscode-eslint|dba|2.4.4
jquerysnippets|don|0.0.1
gitlens|eam|14.8.2
vscode-html-css|ecm|2.0.9
apacheconf-snippets|eim|1.3.0
prettier-vscode|esb|10.1.0
auto-close-tag|for|0.5.15
auto-rename-tag|for|0.1.10
vscode-mysql|for|0.5.0
copilot|Git|1.162.714
copilot-chat|Git|0.12.2
py-paste-indent|hye|0.3.0
fontawesome-autocomplete|Jan|1.3.1
vscode-peacock|joh|4.2.2
vsc-python-indent|Kev|1.18.0
rainbow-csv|mec|3.11.0
dotenv|mik|1.0.1
vscode-nbt|Mis|0.9.1
websocket-client|moh|0.2.0
vscode-html-format|moh|0.1.6
prettify-json|moh|0.0.3
theme-monokai-pro-vscode|mon|1.2.2
vscode-less|mrm|0.6.3
vscode-language-pack-ru|MS-|1.85.2024021409
csharp|ms-|2.15.30
vscode-dotnet-runtime|ms-|2.0.1
debugpy|ms-|2024.0.0
isort|ms-|2023.10.1
python|ms-|2024.0.1
vscode-pylance|ms-|2024.2.2
remote-wsl|ms-|0.86.0
cmake-tools|ms-|1.17.15
cpptools|ms-|1.19.3
cpptools-extension-pack|ms-|1.3.0
hexeditor|ms-|1.9.13
vscode-typescript-next|ms-|5.4.20240218
vsliveshare|ms-|1.0.5905
sftp|Nat|1.16.3
prettier-vscode-with-tabs|pas|1.1.0
total-lines|pra|0.0.1
vscode-css-navigation|puc|1.14.0
pawn|Qoo|0.0.3
format-html-in-php|rif|1.7.0
LiveServer|rit|5.7.9
postcode|roh|1.3.9
markdown-preview-enhanced|shd|0.8.11
vscode-scss-formatter|sib|3.0.0
sass-indented|syl|1.8.29
ejs-snippets|Tao|0.1.0
vscode-fontawesome-gallery|tom|0.0.7
cmake|twx|0.0.17
vscode-icons|vsc|12.7.0
volar|Vue|1.8.27
vscode-typescript-vue-plugin|Vue|1.8.27
quokka-vscode|Wal|1.0.627
vscode-todo-highlight|way|1.0.5
JavaScriptSnippets|xab|1.8.0
php-debug|xde|1.34.0
php-pack|xde|1.0.3
php-intellisense|zob|1.3.3

(2 theme extensions excluded)

</details><details>
<summary>A/B Experiments</summary>

vsliv368:30146709 vspor879:30202332 vspor708:30202333 vspor363:30204092 vswsl492:30256197 vscod805:30301674 vsaa593:30376534 py29gd2263:30784851 c4g48928:30535728 a9j8j154:30646983 962ge761:30841072 pythongtdpath:30726887 welcomedialog:30812478 pythonidxpt:30768918 pythonnoceb:30776497 asynctok:30898717 dsvsc013:30777762 dsvsc014:30777825 dsvsc015:30821418 pythontestfixt:30866404 pythonregdiag2:30926734 pyreplss1:30879911 pythonmypyd1:30859725 pythoncet0:30859736 2e7ec940:30962249 pythontbext0:30879054 accentitlementst:30870582 dsvsc016:30879898 dsvsc017:30880771 dsvsc018:30880772 cppperfcontrol:30963551 8082a590:30961435 b5d27386:30943795 fegfb526:30952798 7j2b6412:30951517 e3gdj431:30946825 78248357:30959762 ccp2r6:30958154

</details>

<!-- generated by issue reporter -->

[ivoiv]

This is a TypeScript issue not a VSCode issue, it happens in TSPlayround as well.