views data cache test comments

gistfile1.diff

diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewsDataTest.php b/core/modules/views/lib/Drupal/views/Tests/ViewsDataTest.php
index bd47a35..b434dc7 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewsDataTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewsDataTest.php
@@ -133,31 +133,35 @@ public function testViewsFetchData() {
    * Ensures that cache entries are only set and get when necessary.
    */
   public function testCache() {
-    // Request the same table 5 times.
+    // Request the same table 5 times. The caches are empty at this point, so
+    // what will happen is that it will first check for a cache entry for the
+    // given table, get a cache miss, then try the cache entry for all tables,
+    // which does not exist yet either. As a result, it rebuilds the information
+    // and writes a cache entry for all tables and the requested table.
     $table_name = 'views_test_data';
     for ($i = 0; $i < 5; $i++) {
       $this->viewsDataCache->get($table_name);
     }
 
-    // Requesting the table did a full rebuild internally, so we have one cache
-    // get for the table, one for the whole storage and we also write both.
-    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:views_test_data:en'), 1);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:en'), 1);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:views_test_data:en'), 1);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:en'), 1);
+    // Assert cache set and get calls.
+    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:views_test_data:en'), 1, 'Requested the cache for the table-specific cache entry.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:en'), 1, 'Requested the cache for all tables.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:views_test_data:en'), 1, 'Wrote the cache for the requested once.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:en'), 1, 'Wrote the cache for the all tables once.');
 
     // Re-initialize the views data cache to simulate a new request and repeat.
+    // We have a warm cache now, so this will only request the tables-specific
+    // cache entry and return that.
     $this->initViewsDataCache();
     for ($i = 0; $i < 5; $i++) {
       $this->viewsDataCache->get($table_name);
     }
 
-    // This only requested the table for which a specific cache entry already
-    // exists. No other cache requests should have been made.
-    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:views_test_data:en'), 1);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:en'), 0);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:views_test_data:en'), 0);
-    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:en'), 0);
+    // Assert cache set and get calls.
+    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:views_test_data:en'), 1, 'Requested the cache for the table-specific cache entry.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('get', 'views_data:en'), 0, 'Did not request to load the cache entry for all tables.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:views_test_data:en'), 0, 'Did not write the cache entry for the requested table.');
+    $this->assertEqual($this->memoryCounterBackend->getCounter('set', 'views_data:en'), 0, 'Did not write the cache for all tables.');
 
     // Re-initialize the views data cache and repeat with no specified table.
     $this->initViewsDataCache();