Form controller bricks intellsense for rest of session #62192
Description
Type: Bug
I have a scenario which is causing Intellisense to break (stuck on "Loading IntelliSense status" indefinitely), meaning I cannot continue development.
My situation:
I am creating a react project using react-hook-form to create a form for a complicated object, hence I am using useFormContext to allow me to nest react function components. My code is as follows:
import { Controller, useFormContext } from "react-hook-form";
import { LargeInterface } from "./somewhere";
interface smallDataStructure {
name: string
}
const ChannelForm: React.FC = () => {
const formControls = useFormContext<smallDataStructure>(); // <--- this does not break vscode
// const formControls = useFormContext<LargeInterface>(); <-- this breaks vscode
return (
<Controller control={formControls.control}></Controller>
)
}
I have narrowed the problem down to giving the useFormContext a generic parameter (which is used to give a type to the field values) which is a very large interface made up of multiple layers of inheritence (I can provide further information on this when necessary). When I use a small interface as depicted above, there is no problem. When I change the code to use the data scructure I need, the line <Controller control={formControls.control}></Controller> can no longer be written without VS bricking for the rest of the session, only fixing when I restart the application (this specifically happens when I write the "control={formControls.control}").
The technologies I am using:
- React.js with Vite
- typescript
- react-hook-form
The typescript engine appears to be unable to handle whatever problem is occurring here. The datastructure I am trying to use as a generic is complex and made up of multiple layers of inheritance, it includes mostly simple datatypes, but also an array of a user defined class objects. This is what is causing the problem! My "LargeInterface" interface looks as follows:
interface LargeInterface inherits MoreSimpleDatatypes {
objs: LargeObject[],
// ... other simple datatypes
}
where LargeObject is, as the name would suggest, a deeply inherited class. I've tried reproducing this with a simple class, but to no avail. There is something about my LargeObject in particular which it does not like. It is probably the case that I am not meant to be using a class as the FieldValues type, but nevertheless, vscode cannot provide the suitable error message in this scenario.
What I've tried:
- Change VS code version, use insiders
- COMPLETELY uninstall all VS code versions from my PC
- Deactivate all plugins
- Change ts version
- Recreate file
- Cleared any cache I could find
- Reclone repo
- Deactivate copilot
Help would be greatly appreciated as I cannot develop on VS code with this problem.
VS Code version: Code - Insiders 1.103.0-insider (994be4137aaf18f2703037311dd1c56a8446ef8b, 2025-08-01T20:53:15.562Z)
OS version: Windows_NT x64 10.0.19045
Modes:
System Info
| Item | Value |
|---|---|
| CPUs | AMD Ryzen 5 3600 6-Core Processor (12 x 3600) |
| GPU Status | 2d_canvas: enabled 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 skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off |
| Load (avg) | undefined |
| Memory (System) | 15.93GB (4.73GB free) |
| Process Argv | --crash-reporter-id cc3d998a-aad8-47bd-8ea7-f068b3586619 |
| Screen Reader | no |
| VM | 0% |
Extensions (5)
| Extension | Author (truncated) | Version |
|---|---|---|
| vscode-containers | ms- | 2.1.0 |
| remote-containers | ms- | 0.424.0 |
| remote-wsl | ms- | 0.99.0 |
| code-spell-checker | str | 4.2.3 |
| vscode-icons | vsc | 12.14.0 |