perf(core): 去掉不需要的初始 setData 和数据字段

packages/mars-core/__test__/unit/swan/swan.test.js

@@ -157,7 +157,13 @@ describe('[swan]createComponent', () => {
         // mock call methods
         component.lifetimes.created.call(component);
         expect(component.$vue).not.toBe(undefined);
-        expect(setData).toHaveBeenCalledTimes(2);
+        // component intial setData omited
+        expect(setData).toHaveBeenCalledTimes(1);
+        component.$vue.a = 2;
+        component.$vue.$nextTick(() => {
+            expect(setData).toHaveBeenCalledTimes(2);
+        });
+
         component.lifetimes.attached.call(component);
         component.lifetimes.ready.call(component);
     });

packages/mars-core/src/base/data.js

@@ -37,14 +37,15 @@ export function setData(vm, $mp, isRoot = false) {
 
     if (!vm.__swan_inited__) {
         vm.__swan_inited__ = true;
-        data.__inited__ = true;
-        isRoot && (data.rootUID = $mp.__uid__);
         data = getData(vm, data);
+        // compare initial data with $mp data
+        // 从 swan properties 和 data 取到的初始数据都是 plain Object 不是 Vue 数据的引用
+        data = compareInitialData($mp, data);
+
         if (isRoot) {
             const rootComputed = getAllComputed(vm);
-            data = Object.assign(data, {
-                rootComputed
-            });
+            data.rootComputed = rootComputed;
+            data.rootUID = $mp.__uid__;
         }
     }
     else {
@@ -67,6 +68,17 @@ export function setData(vm, $mp, isRoot = false) {
         }
     }
 
+    // if vm has _computedWatchers and has new data
+    // set __inited__ true to use VM _computedWatchers data
+    if (
+        vm._computedWatchers
+        && !$mp.data.__inited__
+        && Object.keys(vm._computedWatchers).length > 0
+        && Object.keys(data).length > 0
+    ) {
+        data.__inited__ = true;
+    }
+
     if (process.env.NODE_ENV !== 'production' && config.performance && mark) {
         const prefix = `${vm.$root.$mp.scope.__uid__}$${vm._name}`;
         const perfTagStart = `${prefix}-data-start`;
@@ -100,13 +112,38 @@ export function setData(vm, $mp, isRoot = false) {
         }
         else {
             const flushMpUpdatedCallbacks = getMpUpdatedCallbacks(vm);
+            // console.log('[perf setData]:', data);
             $mp.setData(data, () => {
                 flushMpUpdatedCallbacks();
             });
         }
     }
 }
 
+/**
+ * compare Initial data with $mp.data and omit the same data
+ *
+ * @param {Object} $mp swan instance
+ * @param {Object} data collected data from vm
+ * @return {Object} data omited
+ */
+function compareInitialData($mp, data) {
+    const mpData = $mp.data;
+    const {rootComputed, compId} = mpData;
+    let computedProps = {};
+    if (rootComputed && compId) {
+        computedProps = rootComputed[compId] || {};
+    }
+    Object.keys(data).forEach(key => {
+        let mpVal = mpData[key] !== undefined ? mpData[key] : computedProps[key];
+        if (mpVal !== undefined && deepEqual(data[key], mpVal)) {
+            delete data[key];
+        }
+    });
+
+    return data;
+}
+
 function compareAndSetData(k, val, old, key, data) {
     if (!deepEqual(val, old)) {
         data[`_f_.${k}.` + key] = val;