This rule aims to ensure the correct usage of expect inside waitFor, in the way that they're intended to be used.
When using multiples assertions inside waitFor, if one fails, you have to wait for timeout before see it failing.
Putting one assertion, you can both wait for the UI to settle to the state you want to assert on,
and also fail faster if one of the assertions do end up failing
Example of incorrect code for this rule:
const foo = async () => {
await waitFor(() => {
expect(a).toEqual('a');
expect(b).toEqual('b');
});
// or
await waitFor(function() {
expect(a).toEqual('a')
expect(b).toEqual('b');
})
};Examples of correct code for this rule:
const foo = async () => {
await waitFor(() => expect(a).toEqual('a'));
// this rule only looks for expect
await waitFor(() => {
fireEvent.keyDown(input, { key: 'ArrowDown' });
expect(b).toEqual('b');
});
// or
await waitFor(() => {
console.log('testing-library');
expect(b).toEqual('b');
});
// or
await waitFor(function() {
expect(a).toEqual('a')
})
};