server/helpers/markdown.ts

   1 import { getDefaultSanitizeOptions, getTextOnlySanitizeOptions, TEXT_WITH_HTML_RULES } from '@shared/core-utils'
   2
   3 const defaultSanitizeOptions = getDefaultSanitizeOptions()
   4 const textOnlySanitizeOptions = getTextOnlySanitizeOptions()
   5
   6 const sanitizeHtml = require('sanitize-html')
   7 const markdownItEmoji = require('markdown-it-emoji/light')
   8 const MarkdownItClass = require('markdown-it')
   9
  10 const markdownItForSafeHtml = new MarkdownItClass('default', { linkify: true, breaks: true, html: true })
  11   .enable(TEXT_WITH_HTML_RULES)
  12   .use(markdownItEmoji)
  13
  14 const markdownItForPlainText = new MarkdownItClass('default', { linkify: false, breaks: true, html: false })
  15   .use(markdownItEmoji)
  16   .use(plainTextPlugin)
  17
  18 const toSafeHtml = (text: string) => {
  19   if (!text) return ''
  20
  21   // Restore line feed
  22   const textWithLineFeed = text.replace(/<br.?\/?>/g, '\r\n')
  23
  24   // Convert possible markdown (emojis, emphasis and lists) to html
  25   const html = markdownItForSafeHtml.render(textWithLineFeed)
  26
  27   // Convert to safe Html
  28   return sanitizeHtml(html, defaultSanitizeOptions)
  29 }
  30
  31 const mdToOneLinePlainText = (text: string) => {
  32   if (!text) return ''
  33
  34   markdownItForPlainText.render(text)
  35
  36   // Convert to safe Html
  37   return sanitizeHtml(markdownItForPlainText.plainText, textOnlySanitizeOptions)
  38 }
  39
  40 // ---------------------------------------------------------------------------
  41
  42 export {
  43   toSafeHtml,
  44   mdToOneLinePlainText
  45 }
  46
  47 // ---------------------------------------------------------------------------
  48
  49 // Thanks: https://github.com/wavesheep/markdown-it-plain-text
  50 function plainTextPlugin (markdownIt: any) {
  51   function plainTextRule (state: any) {
  52     const text = scan(state.tokens)
  53
  54     markdownIt.plainText = text
  55   }
  56
  57   function scan (tokens: any[]) {
  58     let lastSeparator = ''
  59     let text = ''
  60
  61     function buildSeparator (token: any) {
  62       if (token.type === 'list_item_close') {
  63         lastSeparator = ', '
  64       }
  65
  66       if (token.tag === 'br' || token.type === 'paragraph_close') {
  67         lastSeparator = ' '
  68       }
  69     }
  70
  71     for (const token of tokens) {
  72       buildSeparator(token)
  73
  74       if (token.type !== 'inline') continue
  75
  76       for (const child of token.children) {
  77         buildSeparator(child)
  78
  79         if (!child.content) continue
  80
  81         text += lastSeparator + child.content
  82         lastSeparator = ''
  83       }
  84     }
  85
  86     return text
  87   }
  88
  89   markdownIt.core.ruler.push('plainText', plainTextRule)
  90 }