added unit testing, and started implementing unit tests...phew

node_modules/p-is-promise/index.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Check if `input` is a ES2015 promise.
+ *
+ * @param input - Value to be checked.
+ *
+ * @example
+ *
+ * import isPromise from 'p-is-promise';
+ *
+ * isPromise(Promise.resolve('🦄'));
+ * //=> true
+ */
+export default function(input: unknown): input is Promise<unknown>;