build: build 2.6.0-beta.2

Author: yyx990803

Diff for: dist/vue.common.dev.js

@@ -1,5 +1,5 @@
 /*!
- * Vue.js v2.6.0-beta.1
+ * Vue.js v2.6.0-beta.2
  * (c) 2014-2019 Evan You
  * Released under the MIT License.
  */
@@ -358,7 +358,7 @@ var LIFECYCLE_HOOKS = [
   'activated',
   'deactivated',
   'errorCaptured',
-  'ssrPrefetch'
+  'serverPrefetch'
 ];
 
 /*  */
@@ -1878,6 +1878,8 @@ function logError (err, vm, info) {
 
 /*  */
 
+var isUsingMicroTask = false;
+
 var callbacks = [];
 var pending = false;
 
@@ -1921,6 +1923,7 @@ if (typeof Promise !== 'undefined' && isNative(Promise)) {
     // "force" the microtask queue to be flushed by adding an empty timer.
     if (isIOS) { setTimeout(noop); }
   };
+  isUsingMicroTask = true;
 } else if (!isIE && typeof MutationObserver !== 'undefined' && (
   isNative(MutationObserver) ||
   // PhantomJS and iOS 7.x
@@ -1939,6 +1942,7 @@ if (typeof Promise !== 'undefined' && isNative(Promise)) {
     counter = (counter + 1) % 2;
     textNode.data = String(counter);
   };
+  isUsingMicroTask = true;
 } else if (typeof setImmediate !== 'undefined' && isNative(setImmediate)) {
   // Fallback to setImmediate.
   // Techinically it leverages the (macro) task queue,
@@ -2737,13 +2741,14 @@ function isWhitespace (node) {
 
 function resolveScopedSlots (
   fns, // see flow/vnode
+  hasDynamicKeys,
   res
 ) {
-  res = res || {};
+  res = res || { $stable: !hasDynamicKeys };
   for (var i = 0; i < fns.length; i++) {
     var slot = fns[i];
     if (Array.isArray(slot)) {
-      resolveScopedSlots(slot, res);
+      resolveScopedSlots(slot, hasDynamicKeys, res);
     } else {
       res[slot.key] = slot.fn;
     }
@@ -2959,12 +2964,22 @@ function updateChildComponent (
   }
 
   // determine whether component has slot children
-  // we need to do this before overwriting $options._renderChildren
-  var hasChildren = !!(
+  // we need to do this before overwriting $options._renderChildren.
+
+  // check if there are dynamic scopedSlots (hand-written or compiled but with
+  // dynamic slot names). Static scoped slots compiled from template has the
+  // "$stable" marker.
+  var hasDynamicScopedSlot = !!(
+    (parentVnode.data.scopedSlots && !parentVnode.data.scopedSlots.$stable) ||
+    (vm.$scopedSlots !== emptyObject && !vm.$scopedSlots.$stable)
+  );
+  // Any static slot children from the parent may have changed during parent's
+  // update. Dynamic scoped slots may also have changed. In such cases, a forced
+  // update is necessary to ensure correctness.
+  var needsForceUpdate = !!(
     renderChildren ||               // has new static slots
     vm.$options._renderChildren ||  // has old static slots
-    parentVnode.data.scopedSlots || // has new scoped slots
-    vm.$scopedSlots !== emptyObject // has old scoped slots
+    hasDynamicScopedSlot
   );
 
   vm.$options._parentVnode = parentVnode;
@@ -3003,7 +3018,7 @@ function updateChildComponent (
   updateComponentListeners(vm, listeners, oldListeners);
 
   // resolve slots + force update if has children
-  if (hasChildren) {
+  if (needsForceUpdate) {
     vm.$slots = resolveSlots(renderChildren, parentVnode.context);
     vm.$forceUpdate();
   }
@@ -3094,10 +3109,32 @@ function resetSchedulerState () {
   waiting = flushing = false;
 }
 
+// Async edge case #6566 requires saving the timestamp when event listeners are
+// attached. However, calling performance.now() has a perf overhead especially
+// if the page has thousands of event listeners. Instead, we take a timestamp
+// every time the scheduler flushes and use that for all event listeners
+// attached during that flush.
+var currentFlushTimestamp = 0;
+
+// Async edge case fix requires storing an event listener's attach timestamp.
+var getNow = Date.now;
+
+// Determine what event timestamp the browser is using. Annoyingly, the
+// timestamp can either be hi-res ( relative to poge load) or low-res
+// (relative to UNIX epoch), so in order to compare time we have to use the
+// same timestamp type when saving the flush timestamp.
+if (inBrowser && getNow() > document.createEvent('Event').timeStamp) {
+  // if the low-res timestamp which is bigger than the event timestamp
+  // (which is evaluated AFTER) it means the event is using a hi-res timestamp,
+  // and we need to use the hi-res version for event listeners as well.
+  getNow = function () { return performance.now(); };
+}
+
 /**
  * Flush both queues and run the watchers.
  */
 function flushSchedulerQueue () {
+  currentFlushTimestamp = getNow();
   flushing = true;
   var watcher, id;
 
@@ -3854,7 +3891,7 @@ function normalizeScopedSlots (
   } else {
     res = {};
     for (var key in slots) {
-      if (slots[key]) {
+      if (slots[key] && key[0] !== '$') {
         res[key] = normalizeScopedSlot(slots[key]);
       }
     }
@@ -3866,6 +3903,7 @@ function normalizeScopedSlots (
     }
   }
   res._normalized = true;
+  res.$stable = slots && slots.$stable;
   return res
 }
 
@@ -4144,6 +4182,31 @@ function bindObjectListeners (data, value) {
 
 /*  */
 
+function bindDynamicKeys (baseObj, values) {
+  for (var i = 0; i < values.length; i += 2) {
+    var key = values[i];
+    if (typeof key === 'string' && key) {
+      baseObj[values[i]] = values[i + 1];
+    } else if (process.env.NODE_ENV !== 'production' && key !== '' && key !== null) {
+      // null is a speical value for explicitly removing a binding
+      warn(
+        ("Invalid value for dynamic directive argument (expected string or null): " + key),
+        this
+      );
+    }
+  }
+  return baseObj
+}
+
+// helper to dynamically append modifier runtime markers to event names.
+// ensure only append when value is already string, otherwise it will be cast
+// to string and cause the type check to miss.
+function prependModifier (value, symbol) {
+  return typeof value === 'string' ? symbol + value : value
+}
+
+/*  */
+
 function installRenderHelpers (target) {
   target._o = markOnce;
   target._n = toNumber;
@@ -4160,6 +4223,8 @@ function installRenderHelpers (target) {
   target._e = createEmptyVNode;
   target._u = resolveScopedSlots;
   target._g = bindObjectListeners;
+  target._d = bindDynamicKeys;
+  target._p = prependModifier;
 }
 
 /*  */
@@ -5265,7 +5330,7 @@ Object.defineProperty(Vue, 'FunctionalRenderContext', {
   value: FunctionalRenderContext
 });
 
-Vue.version = '2.6.0-beta.1';
+Vue.version = '2.6.0-beta.2';
 
 /*  */
 
@@ -6409,6 +6474,7 @@ function _update (oldVnode, vnode) {
     } else {
       // existing directive, update
       dir.oldValue = oldDir.value;
+      dir.oldArg = oldDir.arg;
       callHook$1(dir, 'update', vnode, oldVnode);
       if (dir.def && dir.def.componentUpdated) {
         dirsWithPostpatch.push(dir);
@@ -6686,17 +6752,17 @@ function add$1 (
   capture,
   passive
 ) {
-  if (isChrome) {
-    // async edge case #6566: inner click event triggers patch, event handler
-    // attached to outer element during patch, and triggered again. This only
-    // happens in Chrome as it fires microtask ticks between event propagation.
-    // the solution is simple: we save the timestamp when a handler is attached,
-    // and the handler would only fire if the event passed to it was fired
-    // AFTER it was attached.
-    var now = performance.now();
+  // async edge case #6566: inner click event triggers patch, event handler
+  // attached to outer element during patch, and triggered again. This
+  // happens because browsers fire microtask ticks between event propagation.
+  // the solution is simple: we save the timestamp when a handler is attached,
+  // and the handler would only fire if the event passed to it was fired
+  // AFTER it was attached.
+  if (isUsingMicroTask) {
+    var attachedTimestamp = currentFlushTimestamp;
     var original = handler;
     handler = original._wrapper = function (e) {
-      if (e.timeStamp >= now) {
+      if (e.timeStamp >= attachedTimestamp) {
         return original.apply(this, arguments)
       }
     };
@@ -6777,14 +6843,11 @@ function updateDOMProps (oldVnode, vnode) {
       }
     }
 
-    // #4521: if a click event triggers update before the change event is
-    // dispatched on a checkbox/radio input, the input's checked state will
-    // be reset and fail to trigger another update.
-    // The root cause here is that browsers may fire microtasks in between click/change.
-    // In Chrome / Firefox, click event fires before change, thus having this problem.
-    // In Safari / Edge, the order is opposite.
-    // Note: in Edge, if you click too fast, only the click event would fire twice.
-    if (key === 'checked' && !isNotInFocusAndDirty(elm, cur)) {
+    // skip the update if old and new VDOM state is the same.
+    // the only exception is `value` where the DOM value may be temporarily
+    // out of sync with VDOM state due to focus, composition and modifiers.
+    // This also covers #4521 by skipping the unnecesarry `checked` update.
+    if (key !== 'value' && cur === oldProps[key]) {
       continue
     }