Currently there's no way to validate the size of an array in an implicit attribute:

Validator::make(
    ['foo' => [['bar' => [1, 2, 3]], ['bar' => [1, 2, 3]]]], 
    ['foo.*.bar' => 'size:4']
);

The case is the same with size, between, min, and max.

The reason is that inside the each method all arrays are flattened, so no key will ever has an array value for these rules to work.

$data = Arr::dot($this->initializeAttributeOnData($attribute));

This PR appends exact values for the attribute for each iteration at the end of the $data variable.

NOTE

For these changes to pass the unit tests I had to remove the ValidationValidatorTest::testValidateEach() tests, they hit the each() method directly with invalid validation rules that won't work if applied to the Validator::make() method, and since exact values are now appended to the $data variable these tests will no longer succeed.