Issues using a syntax tree with stringify

[cyberwombat]

I am wanting to create two outputs (doc and toc). So I am approaching this by creating a tree that I then pass to two different processors. However my processor is not accepting my tree:

import unified from'unified'
import markdown from'remark-parse'
import remark2rehype from 'remark-rehype'
import html from 'rehype-stringify'

// This works
const d = unified().use(markdown).use(remark2rehype).use(html).process(fileContents)

// So extract tree
const tree = unified().use(markdown).parse(fileContents)
// Pass tree to processor - does not work - chokes on unknown type in the tree
const doc = unified().use(remark2rehype).use(html).stringify(tree) 

I am using this md as sample

What is the proper way to split above?

[ChristianMurphy]

So I am approaching this by creating a tree that I then pass to two different processors

Can you expand on this?
Are you trying to write multiple files? Or run multiple plugins?

However my processor is not accepting my tree

What do you mean? could you share a codesandbox with an example? (this is a good starting point https://codesandbox.io/s/remark-rehype-debug-4cz8v)

[cyberwombat]

Ah thanks for sandbox link - https://codesandbox.io/s/remark-rehype-debug-forked-etych

So I am wanting to have a table of contents that is separate - I already have all the code to render a toc from a tree. So what I am wanting to do is to 1) create a tree then 2) using that tree create the main html and also pass that tree to my toc builder.

In the sandbox commented out at bottom I have a working example. How can I take that example and end up with the syntax tree AND the final html in a way that minimizes processing.

[ChristianMurphy]

A couple problems:

1. unified stringify doesn't run transforms, remark-rehype is a transform, meaning in your example it is trying to turn a markdown tree into HTML text without having converted to an HTML tree. The overall flow is documented at https://github.com/unifiedjs/unified#description, to make this work run is needed to apply the transform.
2. stringify is not a promise, calling .then will cause an error

see: https://codesandbox.io/s/remark-rehype-debug-forked-4fybi?file=/src/index.js for an example of how this comes together

[cyberwombat]

Ah thank you. All trees are not alike :)