first commit

tests/Post/TaxonUsageCheckerTest.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Post;
+
+use App\Post\Infrastructure\PdoTaxonUsageChecker;
+use PDO;
+use PDOStatement;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+#[\PHPUnit\Framework\Attributes\AllowMockObjectsWithoutExpectations]
+final class TaxonUsageCheckerTest extends TestCase
+{
+    /** @var PDO&MockObject */
+    private PDO $db;
+
+    private PdoTaxonUsageChecker $checker;
+
+    protected function setUp(): void
+    {
+        $this->db = $this->createMock(PDO::class);
+        $this->checker = new PdoTaxonUsageChecker($this->db);
+    }
+
+    private function stmtForScalar(mixed $value): MockObject&PDOStatement
+    {
+        $stmt = $this->createMock(PDOStatement::class);
+        $stmt->method('execute')->willReturn(true);
+        $stmt->method('fetchColumn')->willReturn($value);
+
+        return $stmt;
+    }
+
+    public function testReturnsTrueWhenTaxonIsReferencedByAtLeastOnePost(): void
+    {
+        $stmt = $this->stmtForScalar(1);
+        $this->db->method('prepare')->willReturn($stmt);
+
+        self::assertTrue($this->checker->isTaxonInUse(5));
+    }
+
+    public function testReturnsFalseWhenTaxonIsUnused(): void
+    {
+        $stmt = $this->stmtForScalar(0);
+        $this->db->method('prepare')->willReturn($stmt);
+
+        self::assertFalse($this->checker->isTaxonInUse(5));
+    }
+
+    public function testQueriesPostsTableWithTaxonIdentifier(): void
+    {
+        $stmt = $this->stmtForScalar(0);
+
+        $this->db->expects($this->once())
+            ->method('prepare')
+            ->with($this->stringContains('FROM posts'))
+            ->willReturn($stmt);
+
+        $stmt->expects($this->once())
+            ->method('execute')
+            ->with([':category_id' => 5]);
+
+        $this->checker->isTaxonInUse(5);
+    }
+}