MDL-70316 core: Detect category name changes in the emoji data generator

The emoji data generator script is enabled to detect inconsistencies
between the emoji category names used in the emoji-data library and the
ones used in Moodle. These inconsistencies should be fixed, as soon as
they are detected upon library upgrade.

lib/emoji-data/generate_emoji_data.php

@@ -39,6 +39,8 @@ $rawdata = file_get_contents('./emoji_pretty.json');
 $jsondata = json_decode($rawdata, true);
 $emojibycategory = [];
 $obsoletes = [];
+// Emoji categories used in the emoji-data library.
+$categories = [];
 
 foreach ($jsondata as $data) {
     $category = $data['category'];
@@ -48,6 +50,10 @@ foreach ($jsondata as $data) {
         continue;
     }
 
+    if (!in_array($category, $categories)) {
+        $categories[] = $category;
+    }
+
     if (!empty($data['obsoleted_by'])) {
         // Skip any obsolete emojis. We'll merge these short names into the
         // newer emoji later on.
@@ -71,6 +77,17 @@ foreach ($jsondata as $data) {
         'shortnames' => [$data['short_name']]
     ];
 }
+// Detect any category changes.
+// Some emoji categories from the emoji-data library are missing.
+if ($missingcategories = array_diff($categories, $categorysortorder)) {
+    die("The following categories are missing: " . implode(', ', $missingcategories) .
+        ". For more details on how to properly fix this issue, please see /lib/emoji-data/readme_moodle.txt");
+}
+// Some emoji categories are not being used anymore in the emoji-data library.
+if ($unusedcategories = array_diff($categorysortorder, $categories)) {
+    die("The following categories are no longer used: " . implode(', ', $unusedcategories) .
+        ". For more details on how to properly fix this issue, please see /lib/emoji-data/readme_moodle.txt");
+}
 
 $emojibycategory = array_values($emojibycategory);
 // Sort the emojis within each category into the order specified in the raw data.