Since the html copied from VS Code is not structured as code but as
styled divs for each line, any code copied from it would be pasted
unformatted with blank lines between each line of code.
This has now been fixed, by detecting VS Code style code blocks by the
CSS property `white-space: pre` and pasting the text within as is, as
code.
So far, there were 2 separate turndown rules for code blocks; one for
general ones, and the other for Zulip message code blocks.
Now the filter rule has been generalised to handle both cases together.
As a side effect, the bug where partially copied Zulip code blocks
lost formatting on pasting has been fixed.
When pasting any code without any newlines, whether from a code block or
a code span, it will always be pasted as inline code.
That is, a line of code copied from within a code span will retain code
span formatting on paste, and a line of code copied from within a code
block will be pasted as inline code, instead of a 1 line code block.
Due to the way turndown pads every block element with 2 new lines, and
makes `br` double space by default, we would get 3 blank lines pasted
when there's just 1 line break between 2 paragraphs.
Now we set `br` to an empty string, and since turndown collapses
sequences of multiple new lines to `\n\n` (1 blank line), so any 2 block
elements will now always have 1 blank line between them, irrespective of
if and how many line breaks there are between them in the copied HTML.
Turndown would strip `<style>` tags, but retain the content enclosed.
This resulted in unwanted content being pasted, like the comment nodes
inside the `<style>` tag when pasting cell/s copied from Google Sheets.
If the selection copied, is entirely within a single element, like text
within a heading (like `h1`) we discard this outermost element and only
convert the inner HTML to markdown.
However, we retain `pre` so a code block within it stays as is and does
not change into inline code, losing all its linebreaks.
Turned off and tested escaping with `/` (for now).
Added support + tests for:
- headings.
- strikethrough.
- nested lists.
- code blocks.
Improved handling of:
- links (custom and raw, ignored when wrapping a single image).
- images (now pasted in Zulip's link like syntax).
- custom emojis.
- LaTeX (no garbage symbols, unformatted plain text is pasted)
Added tests for emojis.
Known concerns:
- External images aren't handled anymore by upload.js -- is this a bug?
- Tables lose their formatting on paste.
This lets us simplify the long-ish ‘../../static/js’ paths, and will
remove the need for the ‘zrequire’ wrapper.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Anders Kaseorg
N-Shar-ma
Karl Stolley