--- /dev/null
+/** Symbol.observable addition */
+/* Note: This will add Symbol.observable globally for all TypeScript users,
+ however, we are no longer polyfilling Symbol.observable */
+declare global {
+ interface SymbolConstructor {
+ readonly observable: symbol;
+ }
+}
+
+/** Symbol.observable or a string "@@observable". Used for interop */
+export const observable = (() => typeof Symbol === 'function' && Symbol.observable || '@@observable')();