Bump to v4.13.0.

debounce.js

@@ -1,6 +1,6 @@
-import isObject from './isObject';
-import now from './now';
-import toNumber from './toNumber';
+import isObject from './isObject.js';
+import now from './now.js';
+import toNumber from './toNumber.js';
 
 /** Used as the `TypeError` message for "Functions" methods. */
 var FUNC_ERROR_TEXT = 'Expected a function';
@@ -65,7 +65,7 @@ function debounce(func, wait, options) {
       maxWait,
       result,
       timerId,
-      lastCallTime = 0,
+      lastCallTime,
       lastInvokeTime = 0,
       leading = false,
       maxing = false,
@@ -116,7 +116,7 @@ function debounce(func, wait, options) {
     // Either this is the first call, activity has stopped and we're at the
     // trailing edge, the system time has gone backwards and we're treating
     // it as the trailing edge, or we've hit the `maxWait` limit.
-    return (!lastCallTime || (timeSinceLastCall >= wait) ||
+    return (lastCallTime === undefined || (timeSinceLastCall >= wait) ||
       (timeSinceLastCall < 0) || (maxing && timeSinceLastInvoke >= maxWait));
   }
 
@@ -130,7 +130,6 @@ function debounce(func, wait, options) {
   }
 
   function trailingEdge(time) {
-    clearTimeout(timerId);
     timerId = undefined;
 
     // Only invoke if we have `lastArgs` which means `func` has been
@@ -143,11 +142,8 @@ function debounce(func, wait, options) {
   }
 
   function cancel() {
-    if (timerId !== undefined) {
-      clearTimeout(timerId);
-    }
-    lastCallTime = lastInvokeTime = 0;
-    lastArgs = lastThis = timerId = undefined;
+    lastInvokeTime = 0;
+    lastArgs = lastCallTime = lastThis = timerId = undefined;
   }
 
   function flush() {
@@ -168,7 +164,6 @@ function debounce(func, wait, options) {
       }
       if (maxing) {
         // Handle invocations in a tight loop.
-        clearTimeout(timerId);
         timerId = setTimeout(timerExpired, wait);
         return invokeFunc(lastCallTime);
       }