As described in this answer and in the docs. I've added the reference types for Vitest at the top of my Vite config file.
/// <reference types="vitest" /> Why am I still getting the TypeScript warning 'test' does not exist in type 'UserConfigExport'?
I have found a workaround for this problem - creating separate vitest.config.ts file. As docs states:
Create
vitest.config.ts, which will have the higher priority and will override the configuration fromvite.config.ts
Now you will have intellisense for test option.
Example vitest.config.ts file:
import { defineConfig } from 'vitest/config'; export default defineConfig({ test: { globals: true, environment: 'jsdom', coverage: { provider: 'istanbul', // or 'c8', all: true, }, }, }); 
vite.config.ts before, but then I tried moving the project to monorepo with pnpm workspaces and then the issue appeared, I don't understand why though. If someone has an idea, let me know please.
I defined my own type and extended it to UserConfig.
... import type { InlineConfig } from 'vitest'; import type { UserConfig } from 'vite'; interface VitestConfigExport extends UserConfig { test: InlineConfig; } ... Then I casted the type of config object to my custom interface -
export default defineConfig({ plugins: [solidPlugin()], server: { port: 3000, }, test: { environment: 'jsdom', globals: true, transformMode: { web: [/\.[jt]sx?$/], }, setupFiles: './setupVitest.ts', }, build: { target: 'esnext', }, } as VitestConfigExport); This also enabled intellisense for new test property. Also, you don't need to define /// <reference types="vitest" />.
import { defineConfig } from 'vitest/config';defineConfigfromvitest/configfixes the problem withtest: {...}, but introduces problems in other areas (.e.g'polyfillDynamicImport' does not exist in type 'BuildOptions'). Multiple IDE's give me the same warning even after restart.