SSE: Spec Interpretation Issue (preserve leading spaces) about jooby HOT 1 CLOSED

Hi 👋🏻 https://github.com/mpetazzoni/sse.js author here.

I wanted to bring a point of clarification that sse.js does not expect a space after the colon; it supports both, as required by the SSE specification. When a space is present, it is removed from the value. See https://github.com/mpetazzoni/sse.js/blob/main/lib/sse.js#L218-L222 for the corresponding parsing logic.

For the Jooby authors: I believe you need to handle values (or new lines of the value, if it's broken into multiple data: lines) that start with a leading space by writing it out with two spaces. To write out the following text:

This is my event.
 This second line starts with a leading space.
But not this third one.

You must output:

data:This is my event.
data:  This second line starts with a leading space.
data:But not this third one.

Optionally, this would result in the same value being seen by the client:

data: This is my event.
data:  This second line starts with a leading space.
data: But not this third one.

And that's why it's often always easier to just output SSE fields with a space after the colon. Then you don't need extra logic.

✌🏻

from jooby.