1.rebem.ts

import { createElement, DOMElement, ReactNode } from 'react';

import { stringify, BEMEntity } from 'rebem-classname';

export interface BEMFactory {
    (props: BEMEntity, ...children: ReactNode[]): DOMElement<BEMEntity>
}

function BEM (props: BEMEntity, ...children: ReactNode[]) {
    const tag = props.tag || 'div';
    const className = stringify(props);
    props.className = className

    return createElement(tag, props, ...children);
}

function blockFactory(block: string) : BEMFactory {
    return function (props: BEMEntity, ...children: ReactNode[]) {
        props.block = block
        return BEM(props, ...children);
    };
}

export { BEM, blockFactory };

2.rebem.ts.js

"use strict";
// result of typescript compilation
var react_1 = require('react');
var rebem_classname_1 = require('rebem-classname');
function BEM(props) {
    var children = [];
    for (var _i = 1; _i < arguments.length; _i++) {
        children[_i - 1] = arguments[_i];
    }
    var tag = props.tag || 'div';
    var className = rebem_classname_1.stringify(props);
    props.className = className;
    return react_1.createElement.apply(void 0, [tag, props].concat(children));
}
exports.BEM = BEM;
function blockFactory(block) {
    return function (props) {
        var children = [];
        for (var _i = 1; _i < arguments.length; _i++) {
            children[_i - 1] = arguments[_i];
        }
        props.block = block;
        return BEM.apply(void 0, [props].concat(children));
    };
}
exports.blockFactory = blockFactory;

3.rebem.es6.js

import React from 'react';

import { stringify } from 'rebem-classname';

function BEM(props, ...children) {
    const tag = props.tag || 'div';
    const className = stringify(props);
    const newProps = className ? { ...props, className } : props;

    return React.createElement(tag, newProps, ...children);
}

function blockFactory(block) {
    return function (props, ...children) {
        return BEM({ ...props, block }, ...children);
    };
}

export { BEM, blockFactory };

4.rebem.babel.js

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.blockFactory = exports.BEM = undefined;

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _react = require('react');

var _react2 = _interopRequireDefault(_react);

var _rebemClassname = require('rebem-classname');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function BEM(props) {
    var tag = props.tag || 'div';
    var className = (0, _rebemClassname.stringify)(props);
    var newProps = className ? _extends({}, props, { className: className }) : props;

    for (var _len = arguments.length, children = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
        children[_key - 1] = arguments[_key];
    }

    return _react2.default.createElement.apply(_react2.default, [tag, newProps].concat(children));
}

function blockFactory(block) {
    return function (props) {
        for (var _len2 = arguments.length, children = Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
            children[_key2 - 1] = arguments[_key2];
        }

        return BEM.apply(undefined, [_extends({}, props, { block: block })].concat(children));
    };
}

exports.BEM = BEM;
exports.blockFactory = blockFactory;

https://gist.github.com/Guria/da4f1fabacf8ffcc71e3#file-rebem-ts-L12
https://gist.github.com/Guria/da4f1fabacf8ffcc71e3#file-rebem-ts-L19
typescript missing object rest / spread at the moment :(