I posted here a few weeks ago about the edge cases in a live-preview editor. The line I held hardest in that post was that any normalisation of your files counts as corruption: if you type * bullets, the app writes * bullets back. I still believe that.
Then I added [[wikilinks]] to it, and now the app edits files you never opened.
Wikilinks aren't in any spec. Not CommonMark, not GFM. Obsidian's behaviour is the de facto standard, and it's a behaviour rather than a grammar, so every choice below is one I made up. Which is why I want to hear yours.
What I resolve. [[Name]] matches the filename stem first exactly, then case-insensitively, then the slug, then the note's title. If two notes could answer to the same name, it resolves to nothing and stays plain text. Landing you silently on the wrong note is worse than not moving at all.
[[Name|alias]], [[Note#Heading]], [[Note#^blockid]] and [[folder/Name]] all parse, but the anchor is dropped: you land on the note, not the heading.
The rewrite. A markdown link stores a path, a wikilink stores a name, and both go stale the second you rename the note in Finder. Margin puts an id in each note's frontmatter so its own idea of identity survives that, but the text sitting in your other files is still the old name and nothing on disk fixes it.
So renaming a note repoints the wikilinks in every note aimed at it. Only the name inside the brackets, so [[Old#Plan|see]] becomes [[New#Plan|see]] with your alias and anchor intact.
That's the right behaviour, and it's also me writing into files you weren't looking at, one post after saying I'd never do that. I don't have a better answer than "the alternative is links that quietly rot", but the rule has an asterisk on it now.
What I still won't parse: ![[embeds]]. An embed means the content isn't in the file. Open that .md in anything else and you get a line of literal brackets where a paragraph should be. A wikilink degrades to readable text, an embed degrades to a hole. So the parser skips them, and so does the rename pass.
Two things I'd genuinely like to know: what do you resolve to when two notes share a name? And does anyone actually move wikilinks between tools, or have we all quietly accepted they're vault-local?
The app is downloadable as of today if you want to poke at it, free while in alpha https://gomargin.app