PHPUnit: testing is_a on multiple conditions using data provider - phpunit

Question

I'm trying to write a test for the following method:
/**
* #dataProvider attributesValuesProvider
*/
public function myFunction($entityObject, $diffArr, $prevArr)
{
....
....
if (is_a($entityObject, Customer::class)) {
$entityType = CustomerMetadataInterface::ENTITY_TYPE_CUSTOMER;
} elseif (is_a($entityObject, Address::class)) {
$entityType = AddressMetadataInterface::ENTITY_TYPE_ADDRESS;
} else {
$entityType = null;
}
....
....
return $entityType;
}
I have defined the following data provider:
public function attributesValuesProvider()
{
return [
[null, [], []],
[Customer::class, [], []],
[Address::class, [], []],
];
}
I've twisted this on all sides and I still can't think of a way to write this test. I don't have relevant experience with unit tests so I might be on a wrong path.

Answer 1

Your data provider needs to provide the expected result as well as the method parameters. You can see a simple example in the PHPUnit documentation.
public function attributesValuesProvider()
{
return [
[null, [], [], null],
[new Customer, [], [], CustomerMetadataInterface::ENTITY_TYPE_CUSTOMER],
[new Address, [], [], AddressMetadataInterface::ENTITY_TYPE_ADDRESS],
];
}
The test that uses the data provider will be executed once for each row in the provider, with all the values in the row passed as its arguments. So your test just needs to take all four arguments, call the method and verify that the expected result was returned.
/**
* #dataProvider attributesValuesProvider
*/
public function testMyFunction($object, $diff, $prev, $expected_result) {
$example = new YourClass();
// or maybe you already created this object in your setUp method?
$actual_result = $example->myFunction($object, $diff, $prev);
$this->assertSame($expected_result, $actual_result);
}