flow like the river

BACK_BACK/node_modules/graphql/jsutils/isPromise.js.flow

@@ -0,0 +1,12 @@
+// @flow strict
+/**
+ * Returns true if the value acts like a Promise, i.e. has a "then" function,
+ * otherwise returns false.
+ */
+declare function isPromise(value: mixed): boolean %checks(value instanceof
+  Promise);
+
+// eslint-disable-next-line no-redeclare
+export default function isPromise(value) {
+  return typeof value?.then === 'function';
+}