turndown-plugin-showdown/src/strikethrough.js

Turndown plugin based on the Showdow library

function strikethrough (turndownService) {
    turndownService.addRule('strikethrough', {
      filter: ['del', 's', 'strike'],
      replacement: function (content) {
        return '~~' + content + '~~'
      }
    })
}

module.exports = strikethrough;