From c487b4f6dcbfa35f60c575b5049321bf4be06534 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Evandro=20Leopoldino=20Gon=C3=A7alves?=
 <evandrolgoncalves@gmail.com>
Date: Sun, 18 Apr 2021 12:13:49 +0200
Subject: [PATCH 1/2] implement cancel method to throttle

---
 packages/function-throttle/index.js | 32 +++++++++++++++++++++--------
 test/function-throttle/index.js     | 15 ++++++++++++++
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/packages/function-throttle/index.js b/packages/function-throttle/index.js
index bdb49b110..8cb5f256b 100644
--- a/packages/function-throttle/index.js
+++ b/packages/function-throttle/index.js
@@ -1,35 +1,51 @@
 module.exports = throttle;
 
 function throttle(fn, interval, options) {
-  var wait = false;
+  var timeoutId = null;
   var leading = (options && options.leading);
   var trailing = (options && options.trailing);
+
   if (leading == null) {
     leading = true; // default
   }
+
   if (trailing == null) {
     trailing = !leading; //default
   }
+
   if (leading == true) {
     trailing = false; // forced because there should be invocation per call
   }
 
-  return function() {
-    var callNow = leading && !wait;
+  var cancel = function() {
+    if (timeoutId) {
+      clearTimeout(timeoutId);
+      timeoutId = null;
+    }
+  };
+
+  var throttleWrapper = function() {
+    var callNow = leading && !timeoutId;
     var context = this;
     var args = arguments;
-    if (!wait) {
-      wait = true;
-      setTimeout(function() {
-        wait = false;
+
+    if (!timeoutId) {
+      timeoutId = setTimeout(function() {
+        timeoutId = null;
+
         if (trailing) {
           return fn.apply(context, args);
         }
       }, interval);
     }
+
     if (callNow) {
       callNow = false;
-      return fn.apply(this, arguments);
+      return fn.apply(context, args);
     }
   };
+
+  throttleWrapper.cancel = cancel;
+
+  return throttleWrapper;
 }
diff --git a/test/function-throttle/index.js b/test/function-throttle/index.js
index 052754eeb..ca0b8473c 100644
--- a/test/function-throttle/index.js
+++ b/test/function-throttle/index.js
@@ -392,3 +392,18 @@ test('invokes repeatedly when wait is falsey', function(t) {
     }, 40);
   }, 40);
 });
+
+test('cancel delayed function', function(t) {
+  t.plan(1);
+
+  var callCounter = 0;
+  var fn = throttle(function() {
+    callCounter++;
+  }, 200);
+
+  fn.cancel();
+
+  setTimeout(function() {
+    t.equal(callCounter, 0);
+  }, 400);
+});

From 2ec62a09eb455d19c4c55d42c0844138f9d5534d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Evandro=20Leopoldino=20Gon=C3=A7alves?=
 <evandrolgoncalves@gmail.com>
Date: Thu, 6 May 2021 18:57:32 +0200
Subject: [PATCH 2/2] flat array using iterative solution

---
 packages/array-flatten/index.js | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/packages/array-flatten/index.js b/packages/array-flatten/index.js
index 7610b4f69..78f053369 100644
--- a/packages/array-flatten/index.js
+++ b/packages/array-flatten/index.js
@@ -6,20 +6,21 @@ module.exports = flatten;
 */
 
 function flattenHelper(arr, depth) {
+  var stack = arr.slice();
   var result = [];
-  var len = arr.length;
 
-  for (var i = 0; i < len; i++) {
-    var elem = arr[i];
+  while (stack.length) {
+    var item = stack.pop();
 
-    if (Array.isArray(elem) && depth > 0) {
-      result.push.apply(result, flattenHelper(elem, depth - 1));
+    if (Array.isArray(item) && depth > 0) {
+      stack.push.apply(stack, item);
+      depth--;
     } else {
-      result.push(elem);
+      result.push(item);
     }
   }
 
-  return result;
+  return result.reverse();
 }
 
 function flatten(arr, depth) {
@@ -31,7 +32,5 @@ function flatten(arr, depth) {
     throw new Error('depth expects a number');
   }
 
-  var optionDepth = typeof depth === 'number' ? depth : Infinity;
-
-  return flattenHelper(arr, optionDepth);
+  return flattenHelper(arr, typeof depth === 'number' ? depth : Infinity);
 }