node_modules/remark-stringify/lib/visitors/emphasis.js

'use strict'

module.exports = emphasis

var underscore = '_'
var asterisk = '*'

// Stringify an `emphasis`.
//
// The marker used is configurable through `emphasis`, which defaults to an
// underscore (`'_'`) but also accepts an asterisk (`'*'`):
//
// ```markdown
// *foo*
// ```
//
// In `pedantic` mode, text which itself contains an underscore will cause the
// marker to default to an asterisk instead:
//
// ```markdown
// *foo_bar*
// ```
function emphasis(node) {
  var marker = this.options.emphasis
  var content = this.all(node).join('')

  // When in pedantic mode, prevent using underscore as the marker when there
  // are underscores in the content.
  if (
    this.options.pedantic &&
    marker === underscore &&
    content.indexOf(marker) !== -1
  ) {
    marker = asterisk
  }

  return marker + content + marker
}