Variable vscodeExtKitVitestConfigConst

Drop-in Vitest config: aliases vscode to the kit's documented partial mock at @kkdev92/vscode-ext-kit/testing/vitest and inlines this kit so the alias reaches it.

// vitest.config.ts
import { defineConfig, mergeConfig } from 'vitest/config';
import { vscodeExtKitVitestConfig } from '@kkdev92/vscode-ext-kit/testing/vitest-config';

export default mergeConfig(
  vscodeExtKitVitestConfig,
  defineConfig({
    test: { clearMocks: true, include: ['tests/**/*.test.ts'] },
  })
);
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Why each half is required:

• resolve.alias points every Vite-resolved import ... from 'vscode' at the mock in @kkdev92/vscode-ext-kit/testing/vitest. This makes the replacement a project configuration rule instead of per-test mock setup, and also covers a built bundle when Vite keeps it in the module graph.
• server.deps.inline stops Vitest from externalizing this package. Externalized dependencies load through Node's ESM loader, which knows nothing about Vite aliases — so without this, the kit's own import * as vscode from 'vscode' fails with Cannot find package 'vscode' even though your test files resolve it fine.

This solves module resolution only; it does not turn the partial mock into a real editor. Keep Extension Host tests for behavior outside its documented builders.

Merge order matters only if you also set these keys: mergeConfig concatenates arrays and lets the second argument win on scalars, so passing your own config second is the safe default.

Plain object rather than a defineConfig call, so importing this never drags Vitest's config types into a project that pins a different Vitest major.