Why returnValueMap() is returning NULL - symfony

Question

Trying to mock a doctrine repository inside a test, the returnValueMap() is always returning NULL when used with the findOneBy method.
I have mocked two entities then tried to mock their repository with a given return value map. The test fails and debugging shows that the returnValueMap() is returning NULL.
Here is the class to be tested (the denormalizer)
<?php
declare(strict_types=1);
namespace App\Serializer;
use App\Entity\AdditionalService;
use App\Repository\AdditionalServiceRepository;
use Dto\AdditionalServiceCollection;
use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
class AdditionalServiceCollectionDenormalizer implements DenormalizerInterface
{
/** #var AdditionalServiceRepository */
private $additionalServiceRepository;
public function __construct(AdditionalServiceRepository $additionalServiceRepository)
{
$this->additionalServiceRepository = $additionalServiceRepository;
}
public function denormalize($mappedCsvRow, $class, $format = null, array $context = [])
{
$addtionalServicesCollection = new AdditionalServiceCollection();
foreach ($mappedCsvRow as $fieldName => $fieldValue) {
/** #var AdditionalService $additionalService */
$additionalService = $this->additionalServiceRepository->findOneBy(['name'=>$fieldName]);
if ($additionalService) {
$addtionalServicesCollection->add($additionalService->getId(), $fieldValue);
}
}
return $addtionalServicesCollection;
}
public function supportsDenormalization($data, $type, $format = null)
{
return $type instanceof AdditionalServiceCollection;
}
}
Here is my test class:
<?php
namespace App\Tests\Import\Config;
use App\Entity\AdditionalService;
use App\Repository\AdditionalServiceRepository;
use App\Serializer\AdditionalServiceCollectionDenormalizer;
use PHPUnit\Framework\TestCase;
use Dto\AdditionalServiceCollection;
class AddionalServiceCollectionDenormalizerTest extends TestCase
{
public function provider()
{
$expected = new AdditionalServiceCollection();
$expected->add(1, 22.1)->add(2, 3.1);
return [
[['man_1' => 22.1], $expected],
[['recycling' => 3.1], $expected],
];
}
/**
* #dataProvider provider
* #covers \App\Serializer\AdditionalServiceCollectionDenormalizer::denormalize
*/
public function testDenormalize(array $row, AdditionalServiceCollection $exptected)
{
$manOneService = $this->createMock(AdditionalService::class);
$manOneService->expects($this->any())->method('getId')->willReturn(1);
$recycling = $this->createMock(AdditionalService::class);
$recycling->expects($this->any())->method('getId')->willReturn(2);
$additionalServicesRepoMock = $this
->getMockBuilder(AdditionalServiceRepository::class)
->setMethods(['findOneBy'])
->disableOriginalConstructor()
->getMock();
$additionalServicesRepoMock
->expects($this->any())
->method('findOneBy')
->will($this->returnValueMap(
[
['name'=>['man_1'], $manOneService],
['name'=>['recycling'], $recycling],
]
));
$denormalizer = new AdditionalServiceCollectionDenormalizer($additionalServicesRepoMock);
self::assertEquals($exptected, $denormalizer->denormalize($row, AdditionalServiceCollection::class));
}
}

Answer 1

I had a hard time debugging the PHPUnit library, to figure out finally that it is the findOneBy() method that expects two arguments, among which the second one is optional (set to null)
The willReturnMap() method is as follows:
/**
* Stubs a method by returning a value from a map.
*/
class ReturnValueMap implements Stub
{
/**
* #var array
*/
private $valueMap;
public function __construct(array $valueMap)
{
$this->valueMap = $valueMap;
}
public function invoke(Invocation $invocation)
{
$parameterCount = \count($invocation->getParameters());
foreach ($this->valueMap as $map) {
if (!\is_array($map) || $parameterCount !== (\count($map) - 1)) {
continue;
}
$return = \array_pop($map);
if ($invocation->getParameters() === $map) {
return $return;
}
}
return;
}
I suspected the method was always returning with null because of the unmet condition $parameterCount !== (\count($map) - 1).
A breakpoint confirmed my doubts, and also revealed that $invocation->getParameters() dumps as follows:
array(2) {
[0] =>
array(1) {
'name' =>
string(5) "man_1"
}
[1] =>
NULL
}
Hence, I had to explicitely pass null as second argument.
So finally the working map had to be:
$this->additionalServicesRepoMock
->method('findOneBy')
->willReturnMap([
[['name' => 'man_1'], null, $manOneService],
[['name' => 'recycling'], null, $recyclingService],
]);

Answer 2

It looks like the parameter of returnValueMap() in testDenormalize() needs brackets to make it indexed array.
Here's a slightly modified version of code snippet from the PHPUnit's document:
<?php
namespace App\Tests;
use PHPUnit\Framework\TestCase;
class ReturnValueMapTest extends TestCase
{
public function testReturnValueMapWithAssociativeArray()
{
$stub = $this->createMock(SomeClass::class);
$map = [
[
'name' => ['man_1'],
'Hello'
],
];
$stub->method('doSomething')
->will($this->returnValueMap($map));
// This will fail as doSomething() returns null
$this->assertSame('Hello', $stub->doSomething(['name' => ['man_1']]));
}
public function testReturnValueMapWithIndexedArray()
{
$stub = $this->createMock(SomeClass::class);
$map = [
[
['name' => ['man_1']], // Notice the difference
'Hello'
],
];
$stub->method('doSomething')
->will($this->returnValueMap($map));
$this->assertSame('Hello', $stub->doSomething(['name' => ['man_1']]));
}
}
class SomeClass
{
public function doSomething()
{}
}