From 7d4c56818c77e4d80e8f0706fc7db9857c660b84 Mon Sep 17 00:00:00 2001
From: Gcaufy <gcaufy@gmail.com>
Date: Sat, 7 May 2022 15:27:02 +0800
Subject: [PATCH] fix(core): fix GC problem

during page navigation, for some reason the page and component instance is not released

re #2712
---
 packages/core/weapp/class/Base.js          |  1 +
 packages/core/weapp/class/WepyComponent.js | 29 ++++++++++++++++++++++
 packages/core/weapp/init/lifecycle.js      | 20 +++++++--------
 3 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/packages/core/weapp/class/Base.js b/packages/core/weapp/class/Base.js
index 8a99fa0e1..c37c928c3 100644
--- a/packages/core/weapp/class/Base.js
+++ b/packages/core/weapp/class/Base.js
@@ -5,6 +5,7 @@ export default class Base {
   constructor() {
     this._events = {};
     this._watchers = [];
+    this.$children = [];
   }
 
   $set(target, key, val) {
diff --git a/packages/core/weapp/class/WepyComponent.js b/packages/core/weapp/class/WepyComponent.js
index 21034f77f..c4559946f 100644
--- a/packages/core/weapp/class/WepyComponent.js
+++ b/packages/core/weapp/class/WepyComponent.js
@@ -3,8 +3,16 @@ import Watcher from '../observer/watcher';
 import { isArr, isPlainObject } from '../../shared/index';
 
 import { renderNextTick } from '../util/next-tick';
+import Dirty from './Dirty';
 
 export default class WepyComponent extends Base {
+
+  constructor() {
+    super();
+    this.$children = [];
+    this.$dirty = new Dirty('path');
+    this.$refs = {};
+  }
   $watch(expOrFn, cb, options) {
     let vm = this;
     if (isArr(cb)) {
@@ -52,6 +60,27 @@ export default class WepyComponent extends Base {
   $trigger(event, data, option) {
     this.$wx.triggerEvent(event, { arguments: [data] }, option);
   }
+
+  $destroy() {
+    this.$children.forEach(child => {
+      if (!child._detached) {
+        child.$destroy();
+      }
+    });
+    this._watcher.cleanupDeps();
+    this._watcher.teardown();
+    this._watchers.forEach(item => {
+      item.cleanupDeps();
+      item.teardown();
+    });
+    this._watchers = [];
+    this._events = {};
+    this._detached = true;
+    delete this._data.__ob__;
+    delete this._data;
+    delete this._watcher;
+    delete this.$root;
+  }
 }
 
 WepyComponent.prototype.$nextTick = renderNextTick;
diff --git a/packages/core/weapp/init/lifecycle.js b/packages/core/weapp/init/lifecycle.js
index be7130413..b3b593ac6 100644
--- a/packages/core/weapp/init/lifecycle.js
+++ b/packages/core/weapp/init/lifecycle.js
@@ -9,7 +9,6 @@ import { initData } from './data';
 import { initComputed } from './computed';
 import { initMethods } from './methods';
 import { isArr, isFunc } from '../../shared/index';
-import Dirty from '../class/Dirty';
 import {
   WEAPP_APP_LIFECYCLE,
   WEAPP_PAGE_LIFECYCLE,
@@ -36,7 +35,7 @@ const callUserMethod = function(vm, userOpt, method, args) {
   return result;
 };
 
-const getLifecycycle = (defaultLifecycle, rel, type) => {
+const getLifecycle = (defaultLifecycle, rel, type) => {
   let lifecycle = defaultLifecycle.concat([]);
   if (rel && rel.lifecycle && rel.lifecycle[type]) {
     let userDefinedLifecycle = [];
@@ -75,7 +74,7 @@ export function patchAppLifecycle(appConfig, options, rel = {}) {
     return callUserMethod(vm, vm.$options, 'onLaunch', args);
   };
 
-  let lifecycle = getLifecycycle(WEAPP_APP_LIFECYCLE, rel, 'app');
+  let lifecycle = getLifecycle(WEAPP_APP_LIFECYCLE, rel, 'app');
 
   lifecycle.forEach(k => {
     // it's not defined aready && user defined it && it's an array or function
@@ -92,10 +91,6 @@ export function patchLifecycle(output, options, rel, isComponent) {
   const initLifecycle = function(...args) {
     let vm = new initClass();
 
-    vm.$dirty = new Dirty('path');
-    vm.$children = [];
-    vm.$refs = {};
-
     this.$wepy = vm;
     vm.$wx = this;
     vm.$is = this.is;
@@ -165,7 +160,7 @@ export function patchLifecycle(output, options, rel, isComponent) {
 
     // 增加组件页面声明周期
     output.pageLifetimes = {};
-    const lifecycle = getLifecycycle(WEAPP_COMPONENT_PAGE_LIFECYCLE, rel, 'component');
+    const lifecycle = getLifecycle(WEAPP_COMPONENT_PAGE_LIFECYCLE, rel, 'component');
 
     lifecycle.forEach(function(k) {
       if (!output.pageLifetimes[k] && options[k] && (isFunc(options[k]) || isArr(options[k]))) {
@@ -245,7 +240,7 @@ export function patchLifecycle(output, options, rel, isComponent) {
     //   }
     // })
 
-    let lifecycle = getLifecycycle(WEAPP_PAGE_LIFECYCLE, rel, 'page');
+    let lifecycle = getLifecycle(WEAPP_PAGE_LIFECYCLE, rel, 'page');
 
     lifecycle.forEach(k => {
       if (!output[k] && options[k] && (isFunc(options[k]) || isArr(options[k]))) {
@@ -255,7 +250,12 @@ export function patchLifecycle(output, options, rel, isComponent) {
       }
     });
   }
-  let lifecycle = getLifecycycle(WEAPP_COMPONENT_LIFECYCLE, rel, 'component');
+  output.detached = function(...args) {
+    let vm = this.$wepy;
+    vm.destroy();
+    return callUserMethod(vm, vm.$options, 'detached', args);
+  }
+  let lifecycle = getLifecycle(WEAPP_COMPONENT_LIFECYCLE, rel, 'component');
 
   lifecycle.forEach(k => {
     // beforeCreate is not a real lifecycle