vitest/consistent-each-for

Vitest has two ways to run a test once per row of data. test.each spreads an array row into separate arguments. test.for passes the row as one argument. When a project mixes them, you have to check which one a test uses before you can read its callback's parameters.

The rule does nothing until you choose a method for at least one function.

Configure#

Off by default. To turn it on:

bunfig.toml

[lint.rules]
"vitest/consistent-each-for" = "error" # or "warn"

Every option, set to its default. The ones that are commented out are unset by default.

bunfig.toml

[lint.rules]
"vitest/consistent-each-for" = ["error", {
  # test = <value>,
  # it = <value>,
  # describe = <value>,
  # suite = <value>,
}]

Examples#

bunfig.toml

[lint.rules]
"vitest/consistent-each-for" = ["error", { test = "for" }]

example.tswith { "test": "for" }1 problem

import { expect, test } from "vitest";

test.each([
  [1, 2, 3],
  [2, 3, 5],
])("adds %i and %i", (a, b, sum) => {
  expect(a + b).toBe(sum);
});

example.tswith { "test": "for" }No problems

import { expect, test } from "vitest";

test.for([
  [1, 2, 3],
  [2, 3, 5],
])("adds %i and %i", ([a, b, sum]) => {
  expect(a + b).toBe(sum);
});

Options#

Each option takes the method you want, "each" or "for". A function you leave out isn't checked.

Option	Default	What it does
`test`	not checked	The method for `test`.
`it`	not checked	The method for `it`.
`describe`	not checked	The method for `describe`.
`suite`	not checked	The method for `suite`.

test and it are separate settings. If you only set test, it.each is still allowed:

example.tswith { "test": "for" }No problems

import { expect, it } from "vitest";

it.each([1, 2, 3])("accepts %i", (value) => {
  expect(value).toBeGreaterThan(0);
});