Is there a jest config that will fail tests on console.warn?

You can use this simple override :

let error = console.error

console.error = function (message) {
  error.apply(console, arguments) // keep default behaviour
  throw (message instanceof Error ? message : new Error(message))
}

You can make it available across all tests using Jest setupFiles.

In package.json :

"jest": {
    "setupFiles": [
      "./tests/jest.overrides.js"
    ]
}

Then put the snippet into jest.overrides.js