Incorrect file extension detection for browser files

[rotu]

Type: Bug

1. Create a vite project npm init vite with a debug configuration to open in Chrome.
2. Edit a file to trigger Hot Module Replacement.
3. Stop the debugger on a file that has been edited.

Observe that the file is incorrectly detected as plain text and the filetype extension is wrong.

VS Code version: Code 1.78.0 (252e546, 2023-05-03T20:15:29.774Z)
OS version: Darwin arm64 22.5.0
Modes:
Sandboxed: No

System Info

Item	Value
CPUs	Apple M1 (8 x 24)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled metal: disabled_off 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)	3, 4, 5
Memory (System)	16.00GB (0.24GB free)
Process Argv	vite-project
Screen Reader	no
VM	0%

Extensions: none

[rotu]

The issue appears to be twofold:

1. Filetype detection is based on the URL, not the content-type header a file is served with
2. The filename is not stripped of query parameters when detecting the file name

[rotu]

This appears to be mitigated (at least for my use case) by setting "enableContentValidation": false in the launch configuration, which allows VSCode to associate URLs more leniently with files (where I assume it uses the filename instead of the URL for filetype detection).