Count the number of events from talks

tests/TalkExtensionTest.php

@@ -7,9 +7,49 @@ use PHPUnit\Framework\TestCase;
 
 final class TalkExtensionTest extends TestCase
 {
+    private TalkExtension $subject;
+
+    public function setUp(): void
+    {
+        $this->subject = new TalkExtension();
+    }
+
     /** @test */
     public function it_returns_zero_if_there_are_no_talks(): void
     {
-        $this->assertSame(0, (new TalkExtension())->getPastTalkCount([]));
+        $this->assertSame(0, $this->subject->getPastTalkCount([]));
+    }
+
+    /** @test */
+    public function it_counts_a_single_event_from_a_single_talk(): void
+    {
+        $talks = [
+            [
+                'title' => 'Building static sites with Sculpin',
+                'events' => [
+                    '',
+                ]
+            ],
+        ];
+
+        $this->assertSame(1, $this->subject->getPastTalkCount($talks));
+    }
+
+    /** @test */
+    public function it_counts_multiple_events_from_a_single_talk(): void
+    {
+        $this->markTestIncomplete();
+    }
+
+    /** @test */
+    public function it_counts_multiple_events_from_multiple_talks(): void
+    {
+        $this->markTestIncomplete();
+    }
+
+    /** @test */
+    public function it_excludes_future_talks(): void
+    {
+        $this->markTestIncomplete();
     }
 }