module.exports = api => { const isESMBuild = api.env("esm"); const presets = [ ["@babel/env", { loose: true, }], "@babel/flow", ]; if (isESMBuild) { presets[0][1].targets = { esmodules: true, }; } const plugins = [ "@babel/transform-runtime", ["@babel/proposal-class-properties", { loose: true, }], "version-inline", "preval", ]; return { presets, plugins, }; };