vitest/prefer-to-have-been-called-times

When expect(save.mock.calls).toHaveLength(2) fails, the message is about the length of an array. expect(save).toHaveBeenCalledTimes(2) says what the test means, and its failure message gives the expected and the received number of calls.

--fix rewrites the assertion.

Configure

Off by default. To turn it on:

[lint.rules]
"vitest/prefer-to-have-been-called-times" = "error" # or "warn"

Examples

Reported:

import { expect, test, vi } from "vitest";

test("saves each item once", () => {
  const save = vi.fn();
  saveAll(["a", "b"], save);
  expect(save.mock.calls).toHaveLength(2);
});

Not reported:

import { expect, test, vi } from "vitest";

test("saves each item once", () => {
  const save = vi.fn();
  saveAll(["a", "b"], save);
  expect(save).toHaveBeenCalledTimes(2);
  expect(save.mock.calls[0]).toHaveLength(1); // the arguments of the first call
});