assert i18n dictionaries match on app startup

src/hooks.server.ts

@@ -0,0 +1 @@
+import '$lib/i18n/dicts/_assertions';

src/lib/i18n/dicts/_assertions.ts

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+import { assert } from '$lib/utils';
+import arDict from './ar';
+import enDict from './en';
+
+// Assert that languages dictionaries contain same values
+{
+  const arKeys = new Set(Object.keys(arDict));
+  const enKeys = new Set(Object.keys(enDict));
+
+  const dictsUnion = arKeys.union(enKeys);
+  const dictsIntersection = arKeys.intersection(enKeys);
+  const difference = dictsUnion.difference(dictsIntersection);
+  assert(difference.size == 0, `i18n dictionaries have difference [${[...difference].join(', ')}]`);
+}