{ "presets": [ [ "env", { "modules": false, "targets": { "browsers": ["last 2 versions"], "uglify": true }, "useBuiltIns": true } ], "react", "es2015", "flow" ], "plugins": [ "transform-object-rest-spread", "syntax-dynamic-import", "transform-react-jsx-source", [ "transform-class-properties", { "spec": true } ] ], "env": { "test": { "plugins": ["transform-es2015-modules-commonjs"] } } }