bun:test/prefer-called-times

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.

--fix rewrites the matcher.

Configure

Off by default. To turn it on:

[lint.rules]
"bun:test/prefer-called-times" = "error" # or "warn"

Examples

Reported:

import { expect, mock, test } from "bun:test";

test("does not retry after a success", () => {
  const request = mock();
  retryFetch(request);
  expect(request).toHaveBeenCalledOnce();
});

Not reported:

import { expect, mock, test } from "bun:test";

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

When not to use it

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