Empty document

[stevenvachon]

What are the situations in which parse5 would produce this with the streaming API?:

{ nodeName: '#document', mode: 'no-quirks', childNodes: [] }

Even an empty document at least produces html/head/body elements in my test suite. I'm getting the above with manual testing with a remote server.

[inikulin]

parse5 produces such AST if write or end was never called on a stream. Basically, if stream is in initial state and haven't received any data yet.

[stevenvachon]

Hmm, "never called"? Am I supposed to wait for an event before sending the stream to parse5?

const parser = new parse5.ParserStream(options)
  .once("finish", () => resolve(parser.document));

input.pipe(parser);

If nothing was received, why was "finished" emitted? I'm confused.

[inikulin]

Interesting, seems like node stream doesn't call _write on end without content. Well, that's a bug, as a fix we can write empty string to stream on construction. Care to issue a PR?

[stevenvachon]

It might not be a bug. But you still may want to take some sort of action on this. I was accidentally using bhttp's discardResponse option for non-HEAD requests; which pipes to /dev/null. Do you still want to handle this with an empty string for consistent output, or is this a situation where the developer fucked up and deserves their fate?

[inikulin]

It's a bug. We give erroneous AST on empty string input (which is still a valid input)

[stevenvachon]

I have tests with empty string input that correctly produce ASTs with html/head/body elements.

[inikulin]

Try

const parser = new parse5.ParserStream(options)
  .once("finish", () => resolve(parser.document));

parser.end();

[stevenvachon]

That's different than an empty string, though.

[inikulin]

@stevenvachon That's pretty much the same.

[stevenvachon]

I just noticed that my project's empty string tests were using parse5.parse() and not ParserStream. Testing ParserStream with an empty file or a file containing only whitespace results in the same code as in the initial comment above.

Also, which file do you want the test in?