test: use a dedicated fixture slide for the media checksum tests

Pinning slide_abc_1 by title was still flaky: testRemoveSlide() deletes
the oldest slide of playlist_abc_1, and with randomised fixture
createdAt values that is sometimes slide_abc_1 itself — the lookup then
returned null on the shared per-class database.

Add slide_media_checksum_test (tenant ABC, two known media, attached to
no playlist) following the existing *_relations_checksum_test fixture
convention, and use it in the three media checksum tests. No other test
can mutate or delete it. The ABC slide count grows to 62, so bump the
totalItems assertion in SlidesTest.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: turegjorup

CHANGELOG.md

@@ -4,9 +4,11 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
-- De-flaked `RelationsChecksumListenerTest`: the media-checksum tests now look up a fixture
-  slide that is guaranteed to have media, instead of an unordered `findOneBy()` that could
-  return the media-less `slide_abc_notified` and crash on the missing `media` checksum key.
+- De-flaked `RelationsChecksumListenerTest`: the media-checksum tests now use a dedicated
+  fixture slide (`slide_media_checksum_test`) with known media and no playlist membership.
+  Previously an unordered `findOneBy()` could return the media-less `slide_abc_notified`
+  (crashing on the missing `media` checksum key) or a slide deleted earlier in the class by
+  `testRemoveSlide()`, which removes a random-`createdAt` fixture slide from the shared DB.
 - Fixed the 2.x → 3.0 screen client auto-upgrade path: ship a copy of `release.json` at the
   deprecated `/client/release.json` location polled by 2.x clients. Without it the catch-all
   `/client` route answered with the SPA's HTML and already-running 2.x screens never detected

fixtures/slide.yaml

@@ -37,3 +37,10 @@ App\Entity\Tenant\Slide:
   slide_relations_checksum_test (extends slide):
     title: "slide_relations_checksum_test"
     tenant: "@tenant_xyz"
+  # Dedicated to the media tests in RelationsChecksumListenerTest: known media
+  # (two distinct, so one can be removed and the 'media' checksum key remains)
+  # and on no playlist, so testRemoveSlide() can never delete it.
+  slide_media_checksum_test (extends slide):
+    title: "slide_media_checksum_test"
+    tenant: "@tenant_abc"
+    media: ["@media_abc_1", "@media_abc_2"]

tests/Api/SlidesTest.php

@@ -22,7 +22,7 @@ public function testGetCollection(): void
             '@context' => '/contexts/Slide',
             '@id' => '/v2/slides',
             '@type' => 'hydra:Collection',
-            'hydra:totalItems' => 61,
+            'hydra:totalItems' => 62,
             'hydra:view' => [
                 '@id' => '/v2/slides?itemsPerPage=10&page=1',
                 '@type' => 'hydra:PartialCollectionView',

tests/EventListener/RelationsChecksumListenerTest.php

@@ -210,12 +210,8 @@ public function testPersistSlide(): void
 
     public function testUpdateMedia(): void
     {
-        $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
-        // Look up a fixture slide that is guaranteed to have media: an unordered
-        // findOneBy(['tenant' => ...]) can return slide_abc_notified, which has
-        // none — and then the 'media' checksum key doesn't exist.
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_abc_1', 'tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
 
         $before = $slide->getRelationsChecksum()['media'];
 
@@ -529,10 +525,8 @@ public function testRemoveScreenFromScreenGroupUpdatesChecksum(): void
     public function testAddMediaToSlideUpdatesChecksum(): void
     {
         $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
-        // slide_abc_1 is guaranteed to have media; an unordered findOneBy can
-        // return slide_abc_notified, which has none (no 'media' checksum key).
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_abc_1', 'tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
         $beforeChecksum = $slide->getRelationsChecksum()['media'];
 
         // Find a media not already on this slide
@@ -558,11 +552,8 @@ public function testAddMediaToSlideUpdatesChecksum(): void
 
     public function testRemoveMediaFromSlideUpdatesChecksum(): void
     {
-        $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
-        // slide_abc_1 is guaranteed to have media; an unordered findOneBy can
-        // return slide_abc_notified, which has none (no 'media' checksum key).
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_abc_1', 'tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
         $this->assertGreaterThan(0, $slide->getMedia()->count());
 
         $beforeChecksum = $slide->getRelationsChecksum()['media'];
@@ -573,6 +564,8 @@ public function testRemoveMediaFromSlideUpdatesChecksum(): void
         $this->em->flush();
 
         $this->em->refresh($slide);
+        // The fixture slide has two media, so one remains after the removal and
+        // the 'media' checksum key still exists.
         $this->assertNotEquals($beforeChecksum, $slide->getRelationsChecksum()['media']);
         $this->assertFalse($slide->isChanged());
     }