then(success:failure:)

Schedules the success closure to be invoked on successful completion of self.

JSPromise.swift:128
iOS
13.0+
macOS
10.15+
tvOS
13.0+
watchOS
6.0+
@discardableResult func then(success: sending @escaping (sending JSValue) async throws -> ConvertibleToJSValue, failure: sending @escaping (sending JSValue) async throws -> ConvertibleToJSValue) -> JSPromise