Bili
Bili makes it easier to bundle JavaScript libraries
...Both .js and .ts config files are transpiled by Babel using babel-preset-env and babel-preset-typescript, so feel free to use modern JavaScript features. Bili allows you to add additional Rollup plugins. Automatically transforms JS files using Buble, Babel or TypeScript. Built-in support for CSS, Sass, Stylus, Less and CSS modules. Ridiculously easy to use Rollup plugins if you want. Written in TypeScript, automatically generated API docs. By default Babel transpiles code to ES5, however, you can use Browserslist to specify target environments. Bili supports CSS by default with the help of rollup-plugin-postcss. By default CSS files will be extracted to the same location where the JS is generated but with a .css extension.