OnConnect can be delayed

[pjcdawkins]

The OnConnect callback (added in #137) is only sent during the readLoop so it will only be triggered after the server sends an event, which could be some time (or even never) after a connection is established:

sse/client.go

Line 231 in c6d5381

c.connectedcb(c)

It seems the callback could and should be called here instead, directly after the HTTP response:

sse/client.go

Lines 98 to 100 in c6d5381

	defer resp.Body.Close()
	reader := NewEventStreamReader(resp.Body, c.maxBufferSize)

sse/client.go

Lines 152 to 156 in c6d5381

	if !connected {
	// Notify connect
	errch <- nil
	connected = true
	}

or, at the top of readLoop