Does sse_events correctly detect the end of an SSE event?

[kennethlakin]

https://html.spec.whatwg.org/#parsing-an-event-stream specifies an SSE event as

stream        = [ bom ] *event
event         = *( comment / field ) end-of-line
comment       = colon *any-char end-of-line
field         = 1*name-char [ colon [ space ] *any-char ] end-of-line
end-of-line   = ( cr lf / cr / lf )

; characters
lf            = %x000A ; U+000A LINE FEED (LF)
cr            = %x000D ; U+000D CARRIAGE RETURN (CR)
  ...

So, it looks like we can detect the end of an event by scanning for two EOL characters. https://github.com/inaka/shotgun/blob/master/src/shotgun.erl#L624 does do this, but it only looks for pairs of LF, when it should be looking for pairs of CR, LF, or CR/LF. Mightn't the following code at that line be more complete?

    DataList = binary:split(NewBuffer, [<<"\n\n">>, <<"\r\r">>, <<"\r\n\r\n">>], [global]),

Tiny test from an Erlang shell is below. Note that the removal of any of the patterns in the call to binary:split causes at least one of the test SSEs to fail to have its trailing EOLs removed:

1> A= <<"test server side event\r\n\r\n">>.
<<"test server side event\r\n\r\n">>
2> B= <<"test server side event\r\r">>.    
<<"test server side event\r\r">>
3> C= <<"test server side event\n\n">>. 
<<"test server side event\n\n">>
4> lists:foldl(fun(F, A) -> lists:append(A, [binary:split(F, [<<"\r\r">>, <<"\n\n">>, <<"\r\n\r\n">>], [global])]) end, [], [A, B, C]).
[[<<"test server side event">>,<<>>],
 [<<"test server side event">>,<<>>],
 [<<"test server side event">>,<<>>]]

[jfacorro]

@kennethlakin Your observation is spot on. There is an existing issue (#16) that reports this problem not only for the end of an event but for the different lines that are part of an event. I will close this issue and mark it as duplicated, we can address both problems in issue #16.