@jcayzac/unified-plugins

[!WARNING] This package is not (yet?) meant for public use. It doesn't follow semantic versioning. It is part of a larger project and is published for internal use only.

Remark Preset

import * as presets from '@jcayzac/unified-plugins'

const remarkPlugins = [
  ...otherPlugins,
  ...presets.remark({
    /* options */
  }),
]

// Use remarkPlugins in your unified processor

Linkified headings

All headings are automatically given an id attribute based on their text content, and their children are wrapped in a link to that id.

Unwrapping of "loner" elements

Elements that are the only child of a paragraph are unwrapped from the paragraph if they can be block elements. This includes the following elements:

HTML (or JSX):

• <iframe>
• <img>.
• <figcaption>
• <picture>
• <video>

Markdown:

• image elements.
• link elements that are recognized by a link transform (see below).

Link transforms

Lone links whose URL is recognized by a registered link transform can be altered or transformed into another element.

A link transform conforms to the following interface:

interface LinkTransform {
  // The name of the transform, e.g. `youtube`.
  readonly name: string
  // A regular expression a link's URL must match.
  readonly detect: RegExp
  // Names for captured groups.
  readonly groups?: (string | undefined)[]
  // The transform function.
  readonly transform: (link: Link, ...captured: (string | undefined)[]) => Parent | undefined
}

transform() may just add or change properties on the link, or return a completely new element to replace it.

If the baseline.links.componentRoutes option is set and contains an entry for name, or if the baseline.links.defaultComponent option is set, the link will be replaced by an MDX component and the transform() function ignored.

In addition to url and title, captured groups with a corresponding name in groups are also passed as props to the MDX component, as well as an args prop containing all captured groups.

[!TIP] In order for an MDX component to be available, in must also be registered in the MDX provider.

By default, the following link transforms are registered:

• codepen: Transforms CodePen URLs into responsive iframes loaded lazily. Captured groups:
  • owner: The pen's owner.
  • pen: The pen's id.
• youtube: Transforms YouTube video URLs into responsive iframes loaded lazily. Captured groups:
  • id: The video ID.

You can override the default transforms, or register new ones, by setting the baseline.links.transforms option.

[!NOTE] Markdown links often don't have titles. When a link doesn't have one, the preset automatically sets it to the element's text content before it passes it down to the transform() function or an MDX component.

Asides

GFM-style asides are supported.

> [!NOTE]  
> Highlights information that users should take into account, even when skimming.

> [!TIP]
> Optional information to help a user be more successful.

> [!IMPORTANT]  
> Crucial information necessary for users to succeed.

> [!WARNING]  
> Critical content demanding immediate user attention due to potential risks.

> [!CAUTION]
> Negative potential consequences of an action.

Arbitrary aside types are also supported, for instance:

> [!COOKING_TIP]
> A tip for cooking.

Asides are converted to <aside> elements in rehype. They have a class list that includes aside and aside-<type>, where <type> is the aside type in lowercase.

The aside type is also available in the data attribute of the mdast node, as well as in the data-type attribute set in the rehype node.

A title can be passed as an argument to the aside type:

> [!TIP: I bet you didn't know this!]

Titles are not inserted into the tree, but are available in the data attribute of the mdast node as well as in the data-title attribute of the rehype node.

"Double blockquotes" >> syntax for figure captions

![Alt text](image.jpg)
>> Image caption.
>>
>> Another paragraph in the caption.

The outter blockquote is converted to a <figcaption> in rehype. The inner one is removed, and its children attached to the outter one instead.

Captioning of block elements

Block elements followed by a caption are wrapped in a <figure> element with a <figcaption> child.

The caption element must be at the same level as the block element, and must be a block element itself. It can be a raw <figcaption> or any element marked to be converted to a <figcaption> in rehype.

```js
console.log('Hello, world!')
```

<figcaption>This is a code block.</figcaption>

```js
console.log('Hello, world!')
```

>>This is a code block.

[A video about pandas](https://youtu.be/dqT-UlYlg1s?si=90AKHyMJG_6TLV9p)
>> A video about pandas.

Math

remark-math is included in the preset.

Rehype Preset

import * as presets from '@jcayzac/unified-plugins'

const rehypePlugins = [
  ...otherPlugins,
  ...presets.rehype({
    /* options */
  }),
]

// Use rehypePlugins in your unified processor

Whitespace Cleaning

• Paragraphs are trimmed.
• Empty paragraphs are removed.

Math Typesetting

rehype-katex is included in the preset.