Enforce using expect assertions instead of callbacks (`vitest/prefer-expect-assertions`)

⚠️ This rule warns in the 🌐 all config.

💡 This rule is manually fixable by editor suggestions.

Ensure every test to have either expect.assertions(<number of assertions>) OR expect.hasAssertions() as its first expression.

This will warn if a test has no assertions, or if it has assertions but they are not the first expression.

Examples

Examples of incorrect code for this rule:

test('no assertions', () => {
  // ...
});

test('assertions not first', () => {
  expect(true).toBe(true);
  // ...
});

Examples of correct code for this rule:

test('assertions first', () => {
  expect.assertions(1);
  // ...
});

test('assertions first', () => {
  expect.hasAssertions();
  // ...
});

onlyFunctionsWithAsyncKeyword (default: false)

When true, only functions with the async keyword will be checked.

when this option is enabled the following code will be considered incorrect:

test('assertions first', () => {
   const data = await fetchData();
   expect(data).toBe('peanut butter');
});

To fix this, you'll need to add expect.assertions(1) or expect.hasAssertions() as the first expression:

test('assertions first', () => {
   expect.assertions(1);
   const data = await fetchData();
   expect(data).toBe('peanut butter');
});

onlyFunctionsWithExpectInLoop (default: false)

When true, only functions with expect in a loop will be checked.

when this option is enabled the following code will be considered incorrect:

test('assertions first', () => {
   for (let i = 0; i < 10; i++) {
	 expect(i).toBeLessThan(10);
   }
});

To fix this, you'll need to add expect.assertions(1) or expect.hasAssertions() as the first expression:

test('assertions first', () => {
   expect.hasAssertions();
   for (let i = 0; i < 10; i++) {
	 expect(i).toBeLessThan(10);
   }
});

onlyFunctionsWithExpectInCallback

When true, only functions with expect in a callback will be checked.

when this option is enabled the following code will be considered incorrect:

test('assertions first', () => {
   fetchData((data) => {
	 expect(data).toBe('peanut butter');
   });
});

To fix this, you'll need to add expect.assertions(1) or expect.hasAssertions() as the first expression:

test('assertions first', () => {
   expect.assertions(1);
   fetchData((data) => {
	 expect(data).toBe('peanut butter');
   });
});