Rendering Downshift in a ShadowRoot

// this check is borrowed from react const isProxySupported = typeof Proxy === 'function' && // https://github.com/facebook/react/issues/12011 !Object.isSealed(new Proxy({}, {}));

function createProxyEnvironment(shadowRoot) { const doc = shadowRoot.ownerDocument; const properties = { document: doc, addEventListener: doc.addEventListener.bind(shadowRoot), removeEventListener: doc.removeEventListener.bind(shadowRoot), }; // check if Proxy is supported because of IE and older Safari versions if (isProxySupported) { return new Proxy(shadowRoot, { get: (_, prop) => properties[prop], }) } // fallback for es5-compatible environments (can be removed if it's unnecessary)
return Object.create(shadowRoot, Object.keys(properties).reduce((res, key) => { res[key] = { get: () => properties[key], }; return res; }, {})); }