Needs help using uv_fs_event

[CarterLi]

Hello,

I'm new to libuv, and experimenting it with uv_fs_event ( using uvw if matters ).

There are only two predefined fs events in uv_fs_event. I wrote simple code ( just prints event.filename and event.flags when received fs event) to test it

$ touch a       # printed `a: 1`
$ echo 1 >> a   # printed `a: 1`
$ echo 2 >> a   # printed `a: 1`
$ vim a         # I appended new line to the file a. Sometimes printed `a: 2`, sometimes `a: 1 a: 1`, sometimes `a: 2 a: 2`
$ rm a          # printed `a: 1`

Question: What does the enum UV_RENAME mean? Why appending lines to a file generates UV_RENAME? Why vim a generates different events each time ( seems randomly ).

I think the document should be enriched. It's not very friendly to the newcomers.

Also found a bug when doing quick code searching: https://github.com/libuv/libuv/blob/b01de7341f40e1f30d78178442b0b87a46b3b7a7/test/test-fs-event.c#L202 ( events == UV_CHANGE || UV_RENAME is always true )

The code I was using:

int main() {
    auto loop = uvw::Loop::getDefault();
    auto fsEventHandle = loop->resource<uvw::FsEventHandle>();
    fsEventHandle->start("/Users/Carter/test");
    fsEventHandle->on<uvw::FsEventEvent>([](uvw::FsEventEvent& event, uvw::FsEventHandle& handle) {
        std::printf("%s: %d\n", event.filename, (int)event.flags);
    });
    fsEventHandle->on<uvw::ErrorEvent>([](uvw::ErrorEvent& event, uvw::FsEventHandle& handle) {
        std::printf("ERROR: %d\n", event.code());
    });
    loop->run();
}

Thanks in advance