feat: added Thenable type and isThenable() type guard

src/runtime/type-guards/isThenable.ts

@@ -0,0 +1,8 @@
+import { Thenable } from "src/types/index";
+import { isObject } from "./isObject";
+/**
+* type guard which checks whether passed in `val` is a `Thenable` object
+*/
+export const isThenable = (val: unknown): val is Thenable => {
+  return isObject(val) && "then" in val && "catch" in val && typeof val.then === "function";
+}

src/types/base-types/Thenable.ts

@@ -0,0 +1,12 @@
+import { Dictionary } from "./Dictionary";
+
+/**
+ * **Thenable**`<T>`
+ *
+ * An object which resembles a promise and is guarenteed to provide a `.then` and `.catch`
+ * callback hook.
+ */
+export type Thenable<T = unknown> = Dictionary & {
+  then: (cb: T) => void;
+  catch: (err: string) => void;
+}

src/types/base-types/index.ts

@@ -11,6 +11,7 @@ export * from "./Scalar";
 export * from "./ScalarNotSymbol";
 export * from "./Container";
 export * from "./Tuple";
+export * from "./Thenable";
 export * from "./NumericSign";
 export * from "./Digital";
 export * from "./Indexable";