feat: add withReady()

src/__tests__/index.test.ts

@@ -1,4 +1,4 @@
-import { wait, ReadyStatusEnum } from '../index';
+import { wait, ReadyStatusEnum, withReady } from '../index';
 
 it('resolves with no value set', () => {
     const { setReady, afterReady } = wait();
@@ -77,3 +77,9 @@ it('can set target name', () => {
     setMyTaskReady();
     return expect(afterMyTaskReady()).resolves.toBeUndefined();
 });
+
+it('can wait ready for function withReady', () => {
+    const myFunc = (a: number, b: number) => a + b;
+    const myFuncWithReady = withReady(myFunc, Promise.resolve());
+    return expect(myFuncWithReady(1, 2)).resolves.toBe(3);
+});

src/index.ts

@@ -128,3 +128,21 @@ export const wait = <T, Name extends string = ''>(name?: Name): WaitReturn<T, Na
         },
     } as WaitReturn<T, Name>;
 };
+
+type ParametersTypes<T> = T extends (...args: infer P) => unknown ? P : [];
+type Promisify<T> = T extends Promise<unknown> ? T : Promise<T>;
+
+/**
+ * wrap function to have it run after ready promise resolves
+ * @param func
+ * @param ready promise to wait for
+ * @returns wrapped function returns, promisified
+ */
+export function withReady<T extends (...args: unknown[]) => unknown>(
+    func: T,
+    ready: Promise<unknown>,
+): (...args: ParametersTypes<T>) => Promisify<ReturnType<T>> {
+    return ((...args: ParametersTypes<T>) => {
+        return ready.then(() => func(...args));
+    }) as (...args: ParametersTypes<T>) => Promisify<ReturnType<T>>;
+}