vitest/no-duplicate-hooks

Disallow using the same hook twice in one describe block

Two beforeEach calls in the same block both run, so nothing fails. But someone who reads the first one assumes it's all the setup and misses the second, which can be many lines below.

Hooks are counted per describe block, and the top level of the file counts as a block. A nested describe can have its own beforeEach.

Configure#

Off by default. To turn it on:

bunfig.toml
[lint.rules]
"vitest/no-duplicate-hooks" = "error" # or "warn"

Examples#

example.ts1 problem
import { beforeEach, describe, test } from "vitest";

describe("cart", () => {
  beforeEach(() => {
    cart.clear();
  });

  test("starts empty", () => {});

  beforeEach(() => {
    cart.add("apple");
  });
});
example.tsNo problems
import { beforeEach, describe, test } from "vitest";

describe("cart", () => {
  beforeEach(() => {
    cart.clear();
    cart.add("apple");
  });

  test("has one item", () => {});

  describe("after checkout", () => {
    beforeEach(() => {
      cart.checkout();
    });

    test("is empty", () => {});
  });
});