Add callbackToPromise to util.ts

src/ts/util.ts

@@ -0,0 +1,14 @@
+/**
+ * callbackToPromise converts a callback based function to a promise based function.
+ * The function's only argument must be a function.
+ *
+ * @param {(Function) => void} func
+ * @returns {PromiseLike<any[]>}
+ */
+export function callbackToPromise(func: (Function) => void): PromiseLike<any[]> {
+	return new Promise((resolve) => {
+		func((...callbackArgs) => {
+			resolve(callbackArgs);
+		});
+	});
+}