@mapbox/jsxtreme-markdown/vendor/remark-parse/lib/tokenize/delete.js

Transform Markdown into JSX or React component modules

'use strict';

var whitespace = require('is-whitespace-character');
var locate = require('../locate/delete');

module.exports = strikethrough;
strikethrough.locator = locate;

var tilde = '~';
var fence = '~~';

function strikethrough(eat, value, silent) {
  var self = this;
  var character = '';
  var previous = '';
  var preceding = '';
  var subvalue = '';
  var index;
  var length;
  var now;

  if (
    !self.options.gfm ||
    value.charAt(0) !== tilde ||
    value.charAt(1) !== tilde ||
    whitespace(value.charAt(2))
  ) {
    return;
  }

  index = 1;
  length = value.length;
  now = eat.now();
  now.column += 2;
  now.offset += 2;

  while (++index < length) {
    character = value.charAt(index);

    if (
      character === tilde &&
      previous === tilde &&
      (!preceding || !whitespace(preceding))
    ) {
      /* istanbul ignore if - never used (yet) */
      if (silent) {
        return true;
      }

      return eat(fence + subvalue + fence)({
        type: 'delete',
        children: self.tokenizeInline(subvalue, now),
      });
    }

    subvalue += previous;
    preceding = previous;
    previous = character;
  }
}