Automatically Extract Title from First Heading in Markdown

[Alberthor47]

📋 Automatically Extract Title from First Heading in Markdown

📝 Description

This pull request introduces functionality to automatically extract the title from the first heading in the Markdown document, prioritizing the highest hierarchy (h1 > h2 > h3, etc.), when no title is provided via global directives (marpCLITitle). It ensures that the title is always set appropriately, improving the user experience for slide generation.

🔄 Changes

1. Added the extractTitleFromFirstHeading function to info-plugin.ts:
   • Iterates through Markdown tokens to find the first heading based on hierarchy.
   • Skips malformed or empty headings.
   • Stops searching early when an h1 is found for performance.
2. Updated the infoPlugin to use the extracted title as a fallback when no global directive title is provided.
3. Ensured robust handling of edge cases, such as:
   • No headings in the document.
   • Empty or malformed headings.
   • Multiple headings at the same level.

🎯 Purpose

The primary purpose of this pull request is to enhance the title extraction logic for Marp CLI. It ensures that users who do not explicitly provide a title via global directives still have a meaningful title extracted from their Markdown content, improving the overall usability of the tool.

💬 Additional Comments

Let me know if further adjustments are needed! 🚀

Related Issues

Fixes #131

[yhatt]

Thanks for your working 😄 Could you add the test code for that?

For running code check with CI, please fetch and merge upstream branch main. (I've worked to fix up reported audits on #657)

[Alberthor47]

For sure, working on it!

[Alberthor47]

I'm probably missing something, but Idk why I'm failing check in CI

[yhatt]

https://app.circleci.com/pipelines/github/marp-team/marp-cli/1599/workflows/4cca9757-1155-4087-8cc9-b2fa607e5778/jobs/7554/parallel-runs/0/steps/0-109

CI test has been failed due to the check of code styling by Prettier. In most cases, it could fix just by running npm run format -- --write.

ref. https://github.com/marp-team/.github/blob/master/CONTRIBUTING.md#requirements-in-pull-request

[Alberthor47]

I see, I had conflicts with my local rules. Thanks for the heads up!

[yhatt]

For the initial release is fine with this. In future releases, it would be better to use MarkdownIt.renderInline() to reflect the exact contents.

[yhatt]

It would be better to test with the result of parse by actual Marp or markdown-it instance.

[yhatt]

We've relaxed failure of CI due to vulnerability of depending packages (#663). To merge, an updated condition d6f0682 should pass CI. Sorry for the inconvenience but please fetch and merge upstream branch again.

[Alberthor47]

No worries, I'll like to see this feature so whatever is needed to merge the pr 😄