Running vitest on compiled javascript

Trying to figure out how to run vitest on compiled javascript. Right now I'm getting a bunch of errors that look like:

TypeError: Cannot read properties of undefined (reading 'spyOn')
TypeError: Cannot read properties of undefined (reading 'mock')
etc...

Which are being thrown by references to vi in my code, eg in index.test.ts:

import { vi, it, describe, beforeAll, expect, afterEach } from 'vitest'
vi.mock('some module')

Here is the relevant compilerOptions from the tsconfig in the module:

"compilerOptions": {
  "lib": [
      "es2020",
      "es2015",
      "dom"
  ],
  "module": "commonjs",
  "target": "es2020",
  "esModuleInterop": true,
  "allowSyntheticDefaultImports": true,
  "incremental": true,
  "noImplicitAny": false,
  "moduleResolution": "node",
  "sourceMap": true,
  "outDir": "./dist",
  "strictNullChecks": true,
  "types": [
    "vitest/globals"
  ]
}

Any help would be greatly appreciated. Not even sure if this is possible! I'm new to typescript!

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