---
url: /docs/guide/usage/linter/rules/vitest/consistent-each-for.md
---

### What it does

This rule enforces consistency in which method is used to create parameterized tests.
This configuration affects different test function types (`test`, `it`, `describe`, `suite`).

### Why is this bad?

Without a consistent way to create parameterized tests, we rely on the developer to remember that
`.for` spreads the values as different arguments while `.each` passes the array as a single argument.

### Examples

Examples of **incorrect** code for this rule:

```js
// { test: 'for' }
test.each([[1, 1, 2]])("test", (a, b, expected) => {
  expect(a + b).toBe(expected);
});

// { describe: 'for' }
describe.each([[1], [2]])("suite %s", (n) => {
  test("test", () => {});
});
```

Examples of **correct** code for this rule:

```js
// { test: 'for' }
test.for([[1, 1, 2]])("test", ([a, b, expected]) => {
  expect(a + b).toBe(expected);
});

// { describe: 'for' }
describe.for([[1], [2]])("suite %s", ([n]) => {
  test("test", () => {});
});
```

## Configuration

This rule accepts a configuration object with the following properties:

### describe

type: `"for" | "each"`

Preferred method to create parameterized tests for `describe` blocks.

### it

type: `"for" | "each"`

Preferred method to create parameterized tests for `it` blocks.

### suite

type: `"for" | "each"`

Preferred method to create parameterized tests for `suite` blocks.

### test

type: `"for" | "each"`

Preferred method to create parameterized tests for `test` blocks.

## How to use

## Version

This rule was added in v1.39.0.

## References