@instantish/mack

Mack: Markdown to Slack Message Blocks

Convert Markdown and GitHub Flavoured Markdown to Slack BlockKit Blocks

Mack is a Markdown parser to convert any Markdown content to Slack BlockKit block objects. It uses unified to create a Markdown AST, then converts the AST into Slack objects.

Text is truncated to fit within the Slack API's limits.

Supported Markdown Elements

• All inline elements (italics, bold, strikethrough, inline code, hyperlinks)
• Lists (ordered, unordered, checkboxes)
• All headers
• Code blocks
• Block quotes (with some limitations)
• Images
• Thematic Breaks / Dividers
• Tables (alignment not preserved)

Not Yet Supported Markdown Elements

• Block quotes (limited functionality; does not support lists, headings, or images within the block quote)

Installation

npm install @instantish/mack

Usage

import {markdownToBlocks} from '@instantish/mack';

const blocks = markdownToBlocks(`
# Hello world

* bulleted item 1
* bulleted item 2

abc _123_

![cat](https://images.unsplash.com/photo-1574158622682-e40e69881006)
`);

The blocks object now results in this payload.

API

function markdownToBlocks(text: string, options: ParsingOptions): KnownBlock[]

• text: the content to parse
• options: the options to use when parsing.

Parsing Options

interface ParsingOptions {
  // Configure how lists are displayed
  lists?: ListOptions;
}

interface ListOptions {
  // Configure how checkbox list items are displayed. By default, they are prefixed with '* '
  checkboxPrefix?: (checked: boolean) => string;
}