LibWeb/IDB: Implement IDBIndex::get

Author: https://github.com/stelar7
Commit: e74e571b56
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4727
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/IndexedDB/IDBIndex.cpp

@@ -141,4 +141,35 @@ WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::open_cursor(JS::Value query,
     return request;
 }
 
+// https://w3c.github.io/IndexedDB/#dom-idbindex-get
+WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::get(JS::Value query)
+{
+    auto& realm = this->realm();
+
+    // 1. Let transaction be this’s transaction.
+    auto transaction = this->transaction();
+
+    // 2. Let index be this’s index.
+    auto index = this->index();
+
+    // FIXME: 3. If index or index’s object store has been deleted, throw an "InvalidStateError" DOMException.
+
+    // 4. If transaction’s state is not active, then throw a "TransactionInactiveError" DOMException.
+    if (transaction->state() != IDBTransaction::TransactionState::Active)
+        return WebIDL::TransactionInactiveError::create(realm, "Transaction is not active while getting"_string);
+
+    // 5. Let range be the result of converting a value to a key range with query and true. Rethrow any exceptions.
+    auto range = TRY(convert_a_value_to_a_key_range(realm, query, true));
+
+    // 6. Let operation be an algorithm to run retrieve a referenced value from an index with the current Realm record, index, and range.
+    auto operation = GC::Function<WebIDL::ExceptionOr<JS::Value>()>::create(realm.heap(), [&realm, index, range] -> WebIDL::ExceptionOr<JS::Value> {
+        return retrieve_a_referenced_value_from_an_index(realm, index, range);
+    });
+
+    // 7. Return the result (an IDBRequest) of running asynchronously execute a request with this and operation.
+    auto result = asynchronously_execute_a_request(realm, GC::Ref(*this), operation);
+    dbgln_if(IDB_DEBUG, "Executing request for get with uuid {}", result->uuid());
+    return result;
+}
+
 }