LibWeb/IDB: Implement IDBCursor::continue

Author: https://github.com/stelar7
Commit: 64c4bea189
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4524
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/IndexedDB/IDBCursor.cpp

@@ -66,4 +66,70 @@ JS::Value IDBCursor::key()
     return convert_a_key_to_a_value(realm(), *m_key);
 }
 
+// https://w3c.github.io/IndexedDB/#dom-idbcursor-continue
+WebIDL::ExceptionOr<void> IDBCursor::continue_(JS::Value key)
+{
+    auto& realm = this->realm();
+
+    // 1. Let transaction be this's transaction.
+    auto transaction = this->transaction();
+
+    // 2. 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 continuing cursor"_string);
+
+    // FIXME: 3. If this's source or effective object store has been deleted, throw an "InvalidStateError" DOMException
+
+    // 4. If this's got value flag is false, indicating that the cursor is being iterated or has iterated past its end, throw an "InvalidStateError" DOMException.
+    if (!m_got_value)
+        return WebIDL::InvalidStateError::create(realm, "Cursor is active or EOL"_string);
+
+    // 5. If key is given, then:
+    GC::Ptr<Key> key_value;
+    if (!key.is_undefined()) {
+        // 1. Let r be the result of converting a value to a key with key. Rethrow any exceptions.
+        auto r = TRY(convert_a_value_to_a_key(realm, key));
+
+        // 2. If r is invalid, throw a "DataError" DOMException.
+        if (r->is_invalid())
+            return WebIDL::DataError::create(realm, r->value_as_string());
+
+        // 3. Let key be r.
+        key_value = r;
+
+        // 4. If key is less than or equal to this's position and this's direction is "next" or "nextunique", then throw a "DataError" DOMException.
+        auto is_less_than_or_equal_to = Key::less_than(*key_value, *this->position()) || Key::equals(*key_value, *this->position());
+        if (is_less_than_or_equal_to && (m_direction == Bindings::IDBCursorDirection::Next || m_direction == Bindings::IDBCursorDirection::Nextunique))
+            return WebIDL::DataError::create(realm, "Key is less than or equal to cursor's position"_string);
+
+        // 5. If key is greater than or equal to this's position and this's direction is "prev" or "prevunique", then throw a "DataError" DOMException.
+        auto is_greater_than_or_equal_to = Key::greater_than(*key_value, *this->position()) || Key::equals(*key_value, *this->position());
+        if (is_greater_than_or_equal_to && (m_direction == Bindings::IDBCursorDirection::Prev || m_direction == Bindings::IDBCursorDirection::Prevunique))
+            return WebIDL::DataError::create(realm, "Key is greater than or equal to cursor's position"_string);
+    }
+
+    // 6. Set this's got value flag to false.
+    m_got_value = false;
+
+    // 7. Let request be this's request.
+    auto request = this->request();
+
+    // 8. Set request’s processed flag to false.
+    request->set_processed(false);
+
+    // 9. Set request’s done flag to false.
+    request->set_done(false);
+
+    // 10. Let operation be an algorithm to run iterate a cursor with the current Realm record, this, and key (if given).
+    auto operation = GC::Function<WebIDL::ExceptionOr<JS::Value>()>::create(realm.heap(), [this, &realm, key_value] -> WebIDL::ExceptionOr<JS::Value> {
+        return WebIDL::ExceptionOr<JS::Value>(iterate_a_cursor(realm, *this, key_value));
+    });
+
+    // 11. Run asynchronously execute a request with this's source, operation, and request.
+    asynchronously_execute_a_request(realm, GC::Ref(*this), operation, request);
+    dbgln_if(IDB_DEBUG, "Executing request for cursor continue with uuid {}", request->uuid());
+
+    return {};
+}
+
 }

Libraries/LibWeb/IndexedDB/IDBCursor.h

@@ -47,6 +47,8 @@ public:
     void set_value(JS::Value value) { m_value = value; }
     void set_object_store_position(GC::Ptr<Key> object_store_position) { m_object_store_position = object_store_position; }
 
+    WebIDL::ExceptionOr<void> continue_(JS::Value);
+
 protected:
     explicit IDBCursor(JS::Realm&, GC::Ref<IDBTransaction>, GC::Ptr<Key>, Bindings::IDBCursorDirection, bool, GC::Ptr<Key>, JS::Value, CursorSource, GC::Ref<IDBKeyRange>, bool);
     virtual void initialize(JS::Realm&) override;

Libraries/LibWeb/IndexedDB/IDBCursor.idl

@@ -8,7 +8,7 @@ interface IDBCursor {
     [FIXME] readonly attribute any primaryKey;
     [SameObject] readonly attribute IDBRequest request;
     [FIXME] undefined advance([EnforceRange] unsigned long count);
-    [FIXME] undefined continue(optional any key);
+    undefined continue(optional any key);
     [FIXME] undefined continuePrimaryKey(any key, any primaryKey);
     [FIXME, NewObject] IDBRequest update(any value);
     [FIXME, NewObject] IDBRequest delete();