vitest/prefer-called-times

Require toHaveBeenCalledTimes(1) instead of toHaveBeenCalledOnce()

fixable

toHaveBeenCalledOnce() and toHaveBeenCalledTimes(1) assert the same thing. With toHaveBeenCalledTimes(), every call count is written the same way, and changing the expected count means changing one number. The aliases are covered too, so toBeCalledOnce() becomes toBeCalledTimes(1).

--fix rewrites the matcher.

Configure#

Off by default. To turn it on:

bunfig.toml
[lint.rules]
"vitest/prefer-called-times" = "error" # or "warn"

Examples#

example.ts1 problem
import { expect, test, vi } from "vitest";

test("does not retry after a success", () => {
  const request = vi.fn();
  retryFetch(request);
  expect(request).toHaveBeenCalledOnce();
});
example.tsNo problems
import { expect, test, vi } from "vitest";

test("does not retry after a success", () => {
  const request = vi.fn();
  retryFetch(request);
  expect(request).toHaveBeenCalledTimes(1);
});

When not to use it#

vitest/prefer-called-once asks for the opposite. Turn on one of the two, not both.