add JavaScript/6-timeout-async_callback.js

JavaScript/6-timeout-async_callback.js

@@ -0,0 +1,45 @@
+'use strict';
+
+// Wrapper will prevent call after timeout
+
+const timeoutCallback = (delayCallback, fn) => {
+  // define flag
+  let killFlag = false;
+
+  const timeout = setTimeout(() => {
+    killFlag = true;
+  }, delayCallback);
+
+  return (...args) => {
+    const callback = args[args.length - 1];
+    if (typeof callback === 'function') {
+      args[args.length - 1].flag = killFlag;
+      timeout.close();
+    }
+    fn(...args);
+  };
+};
+
+// Usage
+
+const fn = (par, callback) => {
+  console.log('Function called, par:', par);
+  if(!callback.flag) callback(null, par);
+};
+
+const fn100 = timeoutCallback(100, fn);
+const fn200 = timeoutCallback(200, fn);
+
+setTimeout(() => {
+  fn100('first', (err, data) => {
+    console.log('Callback', data);
+  });
+  fn200('second', (err, data) => {
+    console.log('Callback', data);
+  });
+}, 150);
+
+// console:
+// Function called, par: first
+// Function called, par: second
+// Callback second