From f418115f1bba2975d8cf8b086092b0df5ae507c9 Mon Sep 17 00:00:00 2001 From: Linus Groh Date: Thu, 1 Apr 2021 22:13:29 +0200 Subject: LibJS: Add initial support for Promises Almost a year after first working on this, it's finally done: an implementation of Promises for LibJS! :^) The core functionality is working and closely following the spec [1]. I mostly took the pseudo code and transformed it into C++ - if you read and understand it, you will know how the spec implements Promises; and if you read the spec first, the code will look very familiar. Implemented functions are: - Promise() constructor - Promise.prototype.then() - Promise.prototype.catch() - Promise.prototype.finally() - Promise.resolve() - Promise.reject() For the tests I added a new function to test-js's global object, runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs(). By design, queued jobs normally only run after the script was fully executed, making it improssible to test handlers in individual test() calls by default [2]. Subsequent commits include integrations into LibWeb and js(1) - pretty-printing, running queued promise jobs when necessary. This has an unusual amount of dbgln() statements, all hidden behind the PROMISE_DEBUG flag - I'm leaving them in for now as they've been very useful while debugging this, things can get quite complex with so many asynchronously executed functions. I've not extensively explored use of these APIs for promise-based functionality in LibWeb (fetch(), Notification.requestPermission() etc.), but we'll get there in due time. [1]: https://tc39.es/ecma262/#sec-promise-objects [2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues --- Meta/CMake/all_the_debug_macros.cmake | 1 + 1 file changed, 1 insertion(+) (limited to 'Meta/CMake') diff --git a/Meta/CMake/all_the_debug_macros.cmake b/Meta/CMake/all_the_debug_macros.cmake index bcb8559644..f533be05a9 100644 --- a/Meta/CMake/all_the_debug_macros.cmake +++ b/Meta/CMake/all_the_debug_macros.cmake @@ -144,6 +144,7 @@ set(MENU_DEBUG ON) set(NETWORK_TASK_DEBUG ON) set(OBJECT_DEBUG ON) set(OFFD_DEBUG ON) +set(PROMISE_DEBUG ON) set(PTHREAD_DEBUG ON) set(REACHABLE_DEBUG ON) set(ROUTING_DEBUG ON) -- cgit v1.2.3