My other reply got mangled. I'll leave that post as-is, in case you want to investigate the mess. Flow is not reliable communication medium for discussing Flow bugs because it doesn't have a stable TrueText like wikitext does, and because trying to show troublesome Flow content generally triggers problems. I'll do my best build a non-damaged version of my original post here. Oh jeeze, I copy-pasted it all here and immediately got those little arrows, and a round-trip immediately resulted in new semantic changes. For example the text used to contain the word *was* and a roundtrip turned it into bulletpoint was*
Original post below:
I'll probably split separate subjects into separate replies.
I think you are making the observation that for Flow, this is not sufficient.
Hmm. My first thought was that this issue would spill over to article editing too.... but on second thought maybe not much. I don't really use Visual Editor and I'm still trying to think through the actual-use implications. I think the fact that VisualEditor can't round-trip edit modes during an edit will mostly avoid the nasty trigger situations. But there are definitely latent issues you're not seeing, and I think real-use article-editing errors rates will still be a bit higher than your testing suggests.
The great thing about real wikitext is that newbies can type all sorts of malformed crap into it.... experienced editors can type a malformed half-edit... anyone can accidentally or experimentally type all sorts of malformed crap into it.... and it cheerfully gives you a reasonable best-effort render. No errors, no complaints, the worst that happens is you don't get what you hoped for. Then you play around with your wikitext until you do get what you want.... and you save a single relatively-clean generally-well-formed edit.
In Flow it's common to repeatedly flip edit modes while working up a single edit. That can hit Parasoid with all sorts of random malformed wikitext. And the worst part isn't a rare Parsoid Parse error. The worst part isn't even a fluke semantic change. The worst part is that Parasoid constantly throws your wikitext out the window. Your wikitext is gone, and Parasoid gives you a new mutated blob of wikitext.
Just a single <nowiki>
which becomes <span><nowiki></span>
I lost the edit that triggered the Parasoid Failure. I had reflexively tried to make italics while in visual mode and I got something like this:
<nowiki>'blah' blah blah ''</nowiki>blah blah
The weird placement of the first nowiki tag caught my eye, and I made some random minor edit to see what would happen. I might have unbalanced the nowikis. I toggled the edit mode through 4 or 5 round-trips, it mutated each time. On the final roundtrip Parasoid itself mutated it into something that triggered a Parasoid failure.
(Then I started talking about bugs in that post.)
Ok, I avoided any roundtripping on this post. What I see on my screen right now looks correct. If I *don't* add a new reply, it's because this save looks correct.