Show instructor real name or nickname in group-class views, not the login

Add Auth\UserName::format(), which prefers a user's first + last name, then
their nickname, avoiding display_name (which can be the login/username).
Route the instructor name through it in both the front-end offerings response
(instructor_name) and the back-end group-class summary and details views.

Tests: composer test (513), composer lint, composer cs all pass.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

tests/Unit/Auth/UserNameTest.php

@@ -0,0 +1,47 @@
+<?php
+declare(strict_types=1);
+
+namespace Unsupervised\Schedular\Tests\Unit\Auth;
+
+use Mockery;
+use Unsupervised\Schedular\Auth\UserName;
+use Unsupervised\Schedular\Tests\Unit\TestCase;
+
+class UserNameTest extends TestCase
+{
+    private function user(string $first, string $last, string $nickname): \WP_User
+    {
+        $user = Mockery::mock(\WP_User::class);
+        $user->first_name = $first;
+        $user->last_name  = $last;
+        $user->nickname   = $nickname;
+
+        return $user;
+    }
+
+    public function testPrefersFirstAndLastName(): void
+    {
+        self::assertSame('Ada Lovelace', UserName::format($this->user('Ada', 'Lovelace', 'ada_login')));
+    }
+
+    public function testUsesFirstNameAloneWhenLastNameMissing(): void
+    {
+        self::assertSame('Ada', UserName::format($this->user('Ada', '', 'ada_login')));
+    }
+
+    public function testFallsBackToNicknameWhenNoRealName(): void
+    {
+        self::assertSame('Countess', UserName::format($this->user('', '', 'Countess')));
+    }
+
+    public function testFallsBackToIdWhenNothingSet(): void
+    {
+        self::assertSame('42', UserName::format($this->user('', '', ''), 42));
+    }
+
+    public function testReturnsFallbackIdWhenUserMissing(): void
+    {
+        self::assertSame('42', UserName::format(null, 42));
+        self::assertSame('', UserName::format(null));
+    }
+}

tests/Unit/GroupClass/GroupClassControllerTest.php

@@ -69,6 +69,24 @@ class GroupClassControllerTest extends TestCase
         $_GET = [];
     }
 
+    /**
+     * A WP_User whose real name (and display name) is the given full name, so
+     * both instructor resolution (first + last) and roster display (display name)
+     * render it.
+     */
+    private function userNamed(string $full): \WP_User
+    {
+        [$first, $last] = array_pad(explode(' ', $full, 2), 2, '');
+
+        $user = Mockery::mock(\WP_User::class);
+        $user->first_name   = $first;
+        $user->last_name    = $last;
+        $user->nickname     = $full;
+        $user->display_name = $full;
+
+        return $user;
+    }
+
     private function offering(int $id, string $title, ?int $capacity): Offering
     {
         return new Offering(
@@ -109,7 +127,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testClassDetailListsRosterWithPaymentStatus(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Ada Lovelace'));
         $_GET = ['class_id' => '8'];
 
         $offering   = $this->offering(8, 'Choir', 10);
@@ -131,7 +149,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testClassDetailShowsClassSettingsAndInviteControlsForInviteOnly(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Ada Lovelace'));
         $_GET = ['class_id' => '8'];
 
         $offering = new Offering(
@@ -167,7 +185,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testClassDetailEnrolmentCountExcludesCancelledButRosterKeepsThem(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Grace Hopper']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Grace Hopper'));
         $_GET = ['class_id' => '8'];
 
         $offering  = $this->offering(8, 'Band', null);
@@ -187,7 +205,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testClassDetailFreeEnrolmentShowsDashForPayment(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Alan Turing']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Alan Turing'));
         $_GET = ['class_id' => '8'];
 
         $offering   = $this->offering(8, 'Theory', 5);
@@ -218,7 +236,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testClassDetailWithNoEnrolmentsShowsEmptyMessage(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Ada Lovelace'));
         $_GET = ['class_id' => '8'];
 
         $offering = $this->offering(8, 'Jazz', 5);
@@ -243,7 +261,7 @@ class GroupClassControllerTest extends TestCase
 
     public function testStudioAdminPageSummarisesClassesNotStudents(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Ada Lovelace'));
 
         $offering = new Offering(
             instructorId: 3,
@@ -272,7 +290,7 @@ class GroupClassControllerTest extends TestCase
     public function testStudioAdminCanOpenClassDetailWithInviteControls(): void
     {
         // A studio admin (view_all_lessons) opens a class taught by instructor 7.
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        Functions\when('get_userdata')->justReturn($this->userNamed('Ada Lovelace'));
         $_GET = ['class_id' => '8'];
 
         $offering = new Offering(

tests/Unit/Offering/OfferingEndpointTest.php

@@ -92,7 +92,10 @@ class OfferingEndpointTest extends TestCase
     public function testIndexIncludesInstructorNameForEachOffering(): void
     {
         $instructor = Mockery::mock(\WP_User::class);
-        $instructor->display_name = 'Ada Lovelace';
+        $instructor->first_name   = 'Ada';
+        $instructor->last_name    = 'Lovelace';
+        $instructor->nickname     = 'ada_login';
+        $instructor->display_name = 'ada_login';
         Functions\when('get_userdata')->justReturn($instructor);
 
         $this->repository->shouldReceive('findAll')->andReturn([$this->group(1, Offering::ACCESS_PUBLIC)]);
@@ -100,6 +103,7 @@ class OfferingEndpointTest extends TestCase
 
         $data = $this->endpoint->index(new \WP_REST_Request())->get_data();
 
+        // Real name is shown, not the login-style display name.
         self::assertSame('Ada Lovelace', $data[0]['instructor_name']);
     }