script::dom::servoparser::async_html::Tokenizer uses Err for a non-errror condition

[pshaughn]

This functionally works, but it's misleading:

servo/components/script/dom/servoparser/async_html.rs

Line 268 in ce6204b

pub fn feed(&mut self, input: &mut BufferQueue) -> Result<(), DomRoot<HTMLScriptElement>> {

Returning an HTMLScriptElement is just a normal case here, not an error condition. If Option<DomRoot<HTMLScriptElement>> is undesirable, an enum would be more appropriate than using Result in this way.

[nipunG314]

I would like to refactor this.

Is there any particular reason why an Option here would be undesirable? Also, the feed function in html.rs has the same return type. Should I refactor that as well?

[jdm]

I suspect that Result was used for the benefit of the #[must_use] attribute. It's not legal to use #[must_use] on a function, not just a type, so we can do that instead (https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=5cdb5158697dca6a565185a520b1d499), and use an Option type. And yes, please change the feed function in html.rs.

[nipunG314]

Got it. And are there any relevant tests for the servoparser? Or would a successful build be sufficient?

[jdm]

A successful build will be sufficient.