Improve the logic behind getIdentifiers and Unit Tests coverage

Author: lbajsarowicz

app/code/Magento/Cms/Block/BlockByIdentifier.php

@@ -131,23 +131,28 @@ private function getCurrentStoreId(): int
      */
     public function getIdentities(): array
     {
+        if (!$this->getIdentifier()) {
+            return [];
+        }
+
+        $identities = [
+            self::CACHE_KEY_PREFIX . '_' . $this->getIdentifier(),
+            self::CACHE_KEY_PREFIX . '_' . $this->getIdentifier() . '_' . $this->getCurrentStoreId()
+        ];
+
         try {
             $cmsBlock = $this->getCmsBlock();
 
-            $identities = [self::CACHE_KEY_PREFIX . '_' . $cmsBlock->getId()];
+            $identities[] = self::CACHE_KEY_PREFIX . '_' . $cmsBlock->getId();
 
             if (method_exists($this->getCmsBlock(), 'getStores')) {
-                foreach ($cmsBlock->getStores() as $store) {
-                    $identities[] = self::CACHE_KEY_PREFIX . '_' . $this->getIdentifier() . '_' . $store;
+                foreach ($cmsBlock->getStores() as $storeId) {
+                    $identities[] = self::CACHE_KEY_PREFIX . '_' . $this->getIdentifier() . '_' . $storeId;
                 }
             }
-
-            $identities[] = self::CACHE_KEY_PREFIX . '_' . $this->getIdentifier() . '_' . $this->getCurrentStoreId();
-
-            return $identities;
+            // phpcs:disable Magento2.CodeAnalysis.EmptyBlock.DetectedCatch
         } catch (NoSuchEntityException $e) {
-            // If CMS Block does not exist, it should not be cached
-            return [];
         }
+        return $identities;
     }
 }

app/code/Magento/Cms/Test/Unit/Block/BlockByIdentifierTest.php

@@ -14,6 +14,7 @@
 use Magento\Cms\Model\Template\FilterProvider;
 use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Framework\Filter\Template;
 use Magento\Framework\View\Element\Context;
 use Magento\Store\Api\Data\StoreInterface;
@@ -25,13 +26,18 @@ class BlockByIdentifierTest extends TestCase
 {
     private const STUB_MODULE_OUTPUT_DISABLED = false;
     private const STUB_EXISTING_IDENTIFIER = 'existingOne';
+    private const STUB_UNAVAILABLE_IDENTIFIER = 'notExists';
     private const STUB_DEFAULT_STORE = 1;
     private const STUB_CMS_BLOCK_ID = 1;
     private const STUB_CONTENT = 'Content';
 
     private const ASSERT_EMPTY_BLOCK_HTML = '';
     private const ASSERT_CONTENT_HTML = self::STUB_CONTENT;
     private const ASSERT_NO_CACHE_IDENTITIES = [];
+    private const ASSERT_UNAVAILABLE_IDENTIFIER_BASED_IDENTITIES = [
+        BlockByIdentifier::CACHE_KEY_PREFIX . '_' . self::STUB_UNAVAILABLE_IDENTIFIER,
+        BlockByIdentifier::CACHE_KEY_PREFIX . '_' . self::STUB_UNAVAILABLE_IDENTIFIER . '_' . self::STUB_DEFAULT_STORE
+    ];
 
     /** @var MockObject|GetBlockByIdentifierInterface */
     private $getBlockByIdentifierMock;
@@ -61,12 +67,30 @@ public function testBlockReturnsEmptyStringWhenNoIdentifierProvided(): void
     {
         // Given
         $missingIdentifierBlock = $this->getTestedBlockUsingIdentifier(null);
+        $this->storeMock->method('getId')->willReturn(self::STUB_DEFAULT_STORE);
 
         // Expect
         $this->assertSame(self::ASSERT_EMPTY_BLOCK_HTML, $missingIdentifierBlock->toHtml());
         $this->assertSame(self::ASSERT_NO_CACHE_IDENTITIES, $missingIdentifierBlock->getIdentities());
     }
 
+    public function testBlockReturnsEmptyStringWhenIdentifierProvidedNotFound(): void
+    {
+        // Given
+        $this->getBlockByIdentifierMock->method('execute')->willThrowException(
+            new NoSuchEntityException(__('NoSuchEntityException'))
+        );
+        $missingIdentifierBlock = $this->getTestedBlockUsingIdentifier(self::STUB_UNAVAILABLE_IDENTIFIER);
+        $this->storeMock->method('getId')->willReturn(self::STUB_DEFAULT_STORE);
+
+        // Expect
+        $this->assertSame(self::ASSERT_EMPTY_BLOCK_HTML, $missingIdentifierBlock->toHtml());
+        $this->assertSame(
+            self::ASSERT_UNAVAILABLE_IDENTIFIER_BASED_IDENTITIES,
+            $missingIdentifierBlock->getIdentities()
+        );
+    }
+
     public function testBlockReturnsCmsContentsWhenIdentifierFound(): void
     {
         // Given