feat(service): 兼容小程序开发者工具的 hmr 功能

packages/taro-service/src/platform-plugin-base/mini.ts

@@ -1,5 +1,6 @@
 import { recursiveMerge } from '@tarojs/helper'
 import { isObject, PLATFORM_TYPE } from '@tarojs/shared'
+import * as path from 'path'
 
 import { getPkgVersion } from '../utils/package'
 import TaroPlatform from './platform'
@@ -24,6 +25,8 @@ export abstract class TaroPlatformBase<T extends TConfig = TConfig> extends Taro
   projectConfigJson?: string
   taroComponentsPath?: string
 
+  private projectConfigJsonOutputPath: string
+
   /**
    * 1. 清空 dist 文件夹
    * 2. 输出编译提示
@@ -53,6 +56,18 @@ export abstract class TaroPlatformBase<T extends TConfig = TConfig> extends Taro
       const { printLog, processTypeEnum } = this.ctx.helper
       printLog(processTypeEnum.START, '开发者工具-项目目录', `${this.ctx.paths.outputPath}`)
     }
+    // Webpack5 代码自动热重载
+    if (this.compiler === 'webpack5' && this.config.isWatch && this.projectConfigJsonOutputPath) {
+      try {
+        const projectConfig = require(this.projectConfigJsonOutputPath)
+        if (projectConfig.setting?.compileHotReLoad === true) {
+          this.ctx.modifyWebpackChain(({ chain }) => {
+            chain.plugin('TaroMiniHMRPlugin')
+              .use(require(path.join(__dirname, './webpack/hmr-plugin.js')).default)
+          })
+        }
+      } catch (_) {}
+    }
   }
 
   protected printDevelopmentTip (platform: string) {
@@ -165,6 +180,7 @@ ${exampleCommand}`))
       srcConfigName: src,
       distConfigName: dist
     })
+    this.projectConfigJsonOutputPath = `${this.ctx.paths.outputPath}/${dist}`
   }
 
   /**

packages/taro-service/src/platform-plugin-base/webpack/hmr-plugin.ts

@@ -0,0 +1,37 @@
+export default class TaroMiniHMRPlugin {
+  apply (compiler) {
+    compiler.hooks.thisCompilation.tap('TaroMiniHMRPlugin', compilation => {
+      compilation.hooks.beforeChunkAssets.tap('TaroMiniHMRPlugin', () => {
+        compilation.chunks.forEach(chunk => {
+          if (chunk.hasRuntime() && chunk.name === 'runtime') {
+            const runtimeModules = compilation.chunkGraph.getChunkRuntimeModulesInOrder(chunk)
+            for (const module of runtimeModules) {
+              if (module.name === 'jsonp chunk loading') {
+                const runtimeSource = compilation.codeGenerationResults.getSource(
+                  module,
+                  chunk.runtime,
+                  'runtime'
+                )
+                runtimeSource._value += `
+var miniHMRCallback = function(parentChunkLoadingFunction, data) {
+  var chunkIds = data[0];
+  var moreModules = data[1];
+  if(chunkIds.some(function(id) { return installedChunks[id] === 0 })) {
+    chunkIds.forEach(id => {
+      delete installedChunks[id]
+    })
+    Object.keys(moreModules).forEach(id => {
+      delete __webpack_module_cache__[id]
+    })
+  }
+  if(parentChunkLoadingFunction) parentChunkLoadingFunction(data);
+}
+chunkLoadingGlobal.push = miniHMRCallback.bind(null, chunkLoadingGlobal.push.bind(chunkLoadingGlobal));`
+              }
+            }
+          }
+        })
+      })
+    })
+  }
+}