add services logic

tests/Unit/Services/School/SemesterSelectionServiceTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Tests\Unit\Services\School;
+
+use App\Services\School\SemesterSelectionService;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\DB;
+use Tests\TestCase;
+
+class SemesterSelectionServiceTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_selected_teacher_semester_prefers_session_value(): void
+    {
+        session()->put('teacher_scores_selected_semester', 'spring');
+
+        $service = new SemesterSelectionService();
+
+        $this->assertSame('Spring', $service->selectedTeacherSemester());
+    }
+
+    public function test_selected_teacher_semester_falls_back_to_config(): void
+    {
+        DB::table('configuration')->insert([
+            ['config_key' => 'semester', 'config_value' => 'Fall'],
+        ]);
+
+        session()->forget('teacher_scores_selected_semester');
+        session()->forget('semester');
+
+        $service = new SemesterSelectionService();
+
+        $this->assertSame('Fall', $service->selectedTeacherSemester());
+    }
+}