Eaton's Markup Bucket

Consolidates the setup of assorted markup parsing, scrubbing, and manipulation tools I made heavy use of during the eaton.fyi migration. Generally speaking, everything in this kit is focused on either parsing/extracting stuff from HTML, or translating other common lightweight markup formats into HTML.

Markdown

• fromMarkdown(text: string) takes a Markdown string and spits out HTML. Under the hood it uses marked, augmented by the popular marked-footnote extension. Down the line, more Github-flavored extensions might be added as well.
• toMarkdown(html: string) uses the comparatively less popular but reasonably efficient turndown project; it's configured to use ATX style headers, dashes as bullets, single/double asterisks instead of underscores, and inline link references rather than footnoted ones. A single custom override to the normal formatting is used to ensure bulletted lists have a single-space between the bullet and the text rather than double or triple.

Plaintext

• toText(html: string) accepts a pile of HTML and spits out a reasonably readable plaintext analogue. Under the hood, it uses the extremely customizable HtmlToText library, with a handful of configuration tweaks. A tag's HREF attributes are put in parenthesis after their text, and ignored if the text and href are duplicates of each other. Images are reduced to their alt text, and their URLs are ignored. Several other presets are available in the textPresets collection, the default one can be modified by changing textPresets.default, and you can pass in custom HtmlToTextOption structures to exercise full control.
• fromText(text: string) uses double linebreaks to indentify boundaries for <p> tags, converts URLs and URL-like strings into clickable <a> tags, and can optionally excale HTML entities. Each of those features can be toggled on and off via its options, but out of the box it's handy for turning stuff like oldschool "plain text" blog posts and scraped plaintext into something reasonably nice. Note that passing { inline: true } into the options for this function avoids unecessarily wrapping single-line strings in a <p> tag.

Weird Janky Stuff

• autop(text: string, br: boolean) Uses Wordpress's relatively battle-tested logic for turning CR/LF delimited lines into proper HTML <p> tags; single breaks are ignored, double breaks are treated as new paragraphs. If the br argument is true, single breaks will be turnd into <br> tags.
• fromBBCode(text: string) uses ya-bbcode, to convert BBCode from old forums into HTML. Nothing fancy here, just needed it for some old migrations.
• fromTextile(text: string) uses textile-js to parse and HTMLify Textile markup. MovableType had a popular extension that used Textile to render posts, and a bunch of my old archives turned out to be formatted in it.
• linkify(html: string) turns URLs and domain-like strings into <a> tags, avoiding any that already appear inside of an <a> tag.

Potential Future Stuff

I'd like to consolidate the HTML-to-Markdown and turn it into a special case of HTML-To-Text; it's possible, but would take a bunch of troubleshooting for the edge cases and I'm honestly not THAT passionate about it.

HTML scrubbing/pretty-printing. amd sanitization would be handy but that's also a BIG SPACE, and probably beyond what's reasonable for this already-bloated convenience library.

Text and typography cleanup tools like SmartyPants are handy; I might use textr or typogr, but these things aren't really markup manipulation per se — my own text tools is probably a better place for it.

I'm considering the value of porting more of the conversion bits to unified. Obviously it'd be a giant adventure in gold plating, but it's a consistent base on which most of these different utilities could be consolidated. Maybe when I retire and really, really want to parse my old Setext files, too.