in scripts/contributor.js [102:112]
function getExtensionFromMimeType(mimeType) {
var mimeToExtension = {
'image/jpeg': 'jpg',
'image/png': 'png',
'image/gif': 'gif',
'image/webp': 'webp',
'image/svg+xml': 'svg',
};
return mimeToExtension[mimeType] || 'jpg';
}