typographic-em-dash 
Micro module to fix a common typographic issue that is hard to fix with most keyboard layouts.
This is mainly meant for French typography, it replaces -- by an em dash (en, fr). If the locale is French and we have a pair like — foo —, the first space after the first em dash and the space preceding the second dash will be a narrow no-break space (en, fr).
Submit a PR to src/db.js to add support for your locale.
Install
npm:
npm install --save typographic-em-dashUsage
var dash = require('typographic-em-dash')
dash(`--foo--`, { locale: 'fr' })
// will be replaced by —foo—
dash(`-- foo --`, { locale: 'fr' })
// will be replaced by —NNBSfooNNBs— where NNBS is a narrow no-break space
dash(`--foo--`, { locale: 'en' })
// will be replaced by —foo—
dash(`-- foo --`, { locale: 'en' })
// will be replaced by — foo —This module can also be used through textr.