wikimedia/mediawiki-extensions-UploadWizard

( function ( uw ) {

    var scaleMsgKeys = [ 'size-bytes', 'size-kilobytes', 'size-megabytes', 'size-gigabytes' ];

    uw.units = {
        /**
         * Format a size in bytes for output, using an appropriate
         * unit (bytes, K, MB, GB, or TB) according to the magnitude in question
         *
         * Units above K get 2 fixed decimal places.
         *
         * @param {number} size Number of bytes
         * @return {string} formatted size
         */
        bytes: function ( size ) {
            var i = 0;
            while ( size >= 1024 && i < scaleMsgKeys.length - 1 ) {
                size /= 1024.0;
                i++;
            }
            // Messages are documented above (scaleMsgKeys)
            // eslint-disable-next-line mediawiki/msg-doc
            return mw.message( scaleMsgKeys[ i ], size.toFixed( i > 1 ? 2 : 0 ) ).text();
        }
    };

}( mw.uploadWizard ) );