I don't like that I had to special-case `<p>` tags (top-level
comments) in this code. I feel like it should be possible to handle
top-level comments and replies in a generic way, but I couldn't find
a way to do it that actually worked.
Notes about changes to the behavior, based on the test cases:
* Given a top-level comment A, if there was a "list gap" in the
replies to it: previously new replies would be incorrectly added at
the location of the gap; now they are added after the last reply.
(T242822)
Example: "pl", comment at "08:23, 29 wrz 2018 (CEST)"
* Given a top-level comment A and a reply to it B that skips an
indentation level: previously new replies to A would be added with
the same indentation level as B; now they are added with the
indentation level of A plus one. (The old behavior wasn't a bug, and
this is an accidental effect of other changes, but it seems okay.)
Example: "pl", comment at "03:22, 30 wrz 2018 (CEST)"
and reply at "09:43, 30 wrz 2018 (CEST)"
* Given a top-level comment A, a reply to it B, and a following
top-level comment C that starts at the same indentation level as B:
previously new replies to A would be incorrectly added in the middle
of the comment C, due to the DOM list structure; now they are added
before C. (T241391)
(It seems that comment C was supposed to be a multi-line reply that
was wrongly indented. Unfortunately we have no way to distinguish
this case from a top-level multi-line comment that just happens to
start with a bullet list.)
Example: "pl", comments at "03:36, 24 paź 2018 (CEST)",
"08:35, 24 paź 2018 (CEST)", "17:14, 24 paź 2018 (CEST)"
* In the "en" example, there are some other changes where funnily
nested tags result in slightly different results with the new code.
They don't look important.
* In rare cases, we must split an existing list to add a reply in the
right place. (Basically add `</ul>` before the reply and `<ul>`
after, but it's a bit awkward in DOM terms.)
Example: split-list.html, comment "aaa"; also split-list2.html
(which is the result of saving the previous reply), comment "aaa"
* The modifier can no longer generate DOM that is invalid HTML, fixing
a FIXME in modifier.test.js (or at least, it doesn't happen in these
test cases any more).
Bug: T241391
Bug: T242822
Change-Id: I2a70db01e9a8916c5636bc59ea8490166966d5ec
Document the current behavior of the modifier (which inserts the
replies into the DOM tree), so that we can more easily see the effect
of changes in I2a70db01e9a8916c5636bc59ea8490166966d5ec.
Basically, add a reply to every comment, and dump the resulting HTML,
comparing it to previously generated expected HTML (which can be
checked visually). Have a look at the new HTML files.
Notably, the very first section in the "pl" example demonstrates a
case of wrong reply location due to list gap :) (T242822).
Change-Id: I4aed0f0b112f53d98e3fe1da4d40db8687c7e537
