Created more unit tests

module/Core/test/Visit/VisitsStatsHelperTest.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioTest\Shlink\Core\Visit;
+
+use Doctrine\ORM\EntityManagerInterface;
+use PHPUnit\Framework\TestCase;
+use Prophecy\Prophecy\ObjectProphecy;
+use Shlinkio\Shlink\Core\Entity\Visit;
+use Shlinkio\Shlink\Core\Repository\VisitRepository;
+use Shlinkio\Shlink\Core\Visit\Model\VisitsStats;
+use Shlinkio\Shlink\Core\Visit\VisitsStatsHelper;
+
+use function Functional\map;
+use function range;
+
+class VisitsStatsHelperTest extends TestCase
+{
+    private VisitsStatsHelper $helper;
+    private ObjectProphecy $em;
+
+    public function setUp(): void
+    {
+        $this->em = $this->prophesize(EntityManagerInterface::class);
+        $this->helper = new VisitsStatsHelper($this->em->reveal());
+    }
+
+    /**
+     * @test
+     * @dataProvider provideCounts
+     */
+    public function returnsExpectedVisitsStats(int $expectedCount): void
+    {
+        $repo = $this->prophesize(VisitRepository::class);
+        $count = $repo->count([])->willReturn($expectedCount);
+        $getRepo = $this->em->getRepository(Visit::class)->willReturn($repo->reveal());
+
+        $stats = $this->helper->getVisitsStats();
+
+        $this->assertEquals(new VisitsStats($expectedCount), $stats);
+        $count->shouldHaveBeenCalledOnce();
+        $getRepo->shouldHaveBeenCalledOnce();
+    }
+
+    public function provideCounts(): iterable
+    {
+        return map(range(0, 50, 5), fn (int $value) => [$value]);
+    }
+}