{ "presets": ["flow"], "env": { // Duplications are inevitable due to strange .babelrc env merging: // babel/babel#5276. This can be simplified in Babel 7 using .babelrc.js. "production": { "presets": [["es2015", {"modules": false, "loose": true}]], "plugins": [ "transform-class-properties", "transform-runtime", "version-inline", ], }, "development": { "presets": [["es2015", {"modules": false, "loose": true}]], "plugins": [ "transform-class-properties", "transform-runtime", "version-inline", ], }, "test": { "presets": [["es2015", {"loose": true}]], "plugins": [ "transform-class-properties", "transform-runtime", "version-inline", ], }, "esm": { "plugins": [ "transform-class-properties", "version-inline", ], }, }, }