mirrors/electron
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity Actions 1

fix: update the FileSelectHelper to support the new promise API (#18288)

Browse source 
* fix: update the FileSelectHelper to support the new promise API

Fixes #18254

So it turns out we've successfully introduced a way to write
non-typesafe C++.

This fixes two things:
* Uses the object the promise resolves
* Ensures we attach the Then handler before moving the promise

* fix: also fix misuse of Promise::Then in the download manager
This commit is contained in:
Samuel Attard 2019-05-14 15:46:53 -07:00 • committed by GitHub
parent d027be05a6
commit fde3137b90
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 78 additions and 79 deletions
Download patch file Download diff file Expand all files Collapse all files

20
atom/common/promise_util.h
View file

@ -104,9 +104,25 @@ class Promise {
return GetInner()->Reject(GetContext(), v8::Undefined(isolate()));
}
template <typename ReturnType, typename... ArgTypes>
// Please note that using Then is effectively the same as calling .then
// in javascript. This means (a) it is not type safe and (b) please note
// it is NOT type safe.
// If the base::Callback you provide here is of type void(boolean) and you
// resolve the promise with a string, Electron will compile successfully and
// then that promise will be rejected as soon as you try to use it as the
// mate converters doing work behind the scenes will throw an error for you.
// This can be really hard to trace so until either
// * This helper becomes typesafe (by templating the class instead of each
// method)
// * or the world goes mad
// Please try your hardest not to use this method
// The world thanks you
template <typename... ResolveType>
v8::MaybeLocal<v8::Promise> Then(
base::OnceCallback<ReturnType(ArgTypes...)> cb) {
base::OnceCallback<void(ResolveType...)> cb) {
static_assert(sizeof...(ResolveType) <= 1,
"A promise's 'Then' callback should only receive at most one "
"parameter");
v8::HandleScope handle_scope(isolate());
v8::Context::Scope context_scope(
v8::Local<v8::Context>::New(isolate(), GetContext()));