theisel / astro-toc Goto Github PK

Describe the bug

Here's an example list of headers in markdown:

## hello
## world
### a. test
### b. this

The H3 header ### b. this does not show up.

Debugging

The culprit are lines 39-40 of TOC.astro:

const nextHeading = headings[idx + 1]
const subHeadings = toc.slice((toc as any).indexOf(it) + 1, (toc as any).indexOf(nextHeading));

If we're iterating through all the headings with depth=2, then when we're at the last element ## world, there is no more heading after it. This causes nextHeading to be undefined.

So when calculating subHeadings, the second argument passed into slice is toc.indexOf(undefined) which is -1. This means that the slice will only return the next item, and not retrieve the last item.

Proposed fix

const nextHeading = headings[idx + 1];
let subHeadings = toc.slice((toc as any).indexOf(it) + 1, (toc as any).indexOf(nextHeading));
if (!nextHeading) subHeadings = toc.slice((toc as any).indexOf(it) + 1);

If nextHeading is undefined, then subHeadings will just grab the remainder of toc.

I am using <TOC /> but I noticed that it does not render when the toc only includes h2 and h3 headings. Currently, I am quickfixing it by manually pushing an h1 heading (depth: 1) into my toc:

toc.unshift({
  title: 'Glossary',
  depth: 1,
  url: '',
});

Would it be possible to render a TOC even when there is no h1?