tree shake

docs/cli/configuration.md

@@ -146,6 +146,13 @@ module.exports = {
 ### optimization.allowEmptyAttributes
 是否允许空属性，默认 `true`，不要改动该配置，除非你清楚自己要做什么:warning:。
 
+## treeShake
+
+- **类型**: `Boolean` default: `false`
+- **用法**:
+
+是否开启 `tree-shake` 。只有为 `true` 且非 `watch` 模式下 `tree-shake` 才会生效。
+
 ## plugins
 
 目前支持的插件有：

package.json

@@ -54,6 +54,7 @@
 	},
 	"dependencies": {
 		"@vuepress/theme-default": "^1.5.4",
+		"lodash": "^4.17.21",
 		"vue-server-renderer": "^2.6.12"
 	}
 }

packages/wxa-cli/.eslintrc.json

@@ -27,7 +27,8 @@
         "no-trailing-spaces": "off",
         "require-jsdoc": "off",
         "camelcase": "warn",
-        "no-invalid-this": "warn"
+        "no-invalid-this": "warn",
+        "linebreak-style": ["off", "windows"]
     },
     "plugins": []
 }

packages/wxa-cli/package.json

@@ -69,7 +69,8 @@
     "promise.prototype.finally": "^3.1.0",
     "shelljs": "^0.8.3",
     "tapable": "^1.0.0",
-    "valid-url": "^1.0.9"
+    "valid-url": "^1.0.9",
+    "lodash": "^4.17.21"
   },
   "publishConfig": {
     "access": "public"

packages/wxa-cli/src/const/wxaConfigs.js

@@ -43,6 +43,7 @@ export default class DefaultWxaConfigs {
                 allowEmptyAttributes: true,
                 transformPxToRpx: false,
             },
+            treeShake: false,
         };
     }
 }

packages/wxa-cli/src/schedule.js

@@ -17,6 +17,7 @@ import DependencyResolver from './helpers/dependencyResolver';
 import ProgressTextBar from './helpers/progressTextBar';
 import Preformance from './helpers/performance';
 import simplify from './helpers/simplifyObj';
+import {treeShake} from './tree-shake/index';
 
 let debug = debugPKG('WXA:Schedule');
 
@@ -72,6 +73,7 @@ class Schedule {
         // if is mounting compiler, all task will be blocked.
         this.$isMountingCompiler = false;
         this.progress = new ProgressTextBar(this.current, wxaConfigs);
+        this.$depJsPending = [];
 
         // save all app configurations for compile time.
         // such as global components.
@@ -120,17 +122,28 @@ class Schedule {
 
     async $doDPA() {
         let tasks = [];
+
         while (this.$depPending.length) {
             let dep = this.$depPending.shift();
 
+            if (this.wxaConfigs.treeShake && !this.cmdOptions.watch && dep.src.endsWith('.js')) {
+                this.$depJsPending.push(dep);
+            } else {
+                tasks.push(this.$parse(dep));
+            }
+
             // debug('file to parse %O', dep);
-            tasks.push(this.$parse(dep));
         }
 
         let succ = await Promise.all(tasks);
 
         if (this.$depPending.length === 0) {
             // dependencies resolve complete
+            if (this.wxaConfigs.treeShake && !this.cmdOptions.watch) {
+                let sub = await this.$dojsDPA();
+                return succ.concat(sub);
+            }
+
             this.progress.clean();
             return succ;
         } else {
@@ -139,6 +152,53 @@ class Schedule {
         }
     }
 
+    async $dojsDPA() {
+        this.$depPending = this.$depJsPending;
+        this.$depJsPending = [];
+        let entries = this.$depPending.map((item)=>({src: item.src, content: item.content}));
+        console.time('shake');
+        let contents = treeShake(
+            {
+                entry: entries,
+                resolveSrc: {
+                    root: 'src',
+                    alias: this.wxaConfigs.resolve.alias,
+                },
+                commonJS: {
+                    enable: true,
+                },
+            }
+        );
+        console.timeEnd('shake');
+
+        let run = async () => {
+            let tasks = [];
+
+            while (this.$depPending.length) {
+                let dep = this.$depPending.shift();
+                let content = contents[dep.src] && contents[dep.src].formattedCode;
+                if (content) {
+                    dep.content = content;
+                }
+
+                tasks.push(this.$parse(dep));
+            }
+
+            let succ = await Promise.all(tasks);
+
+            if (this.$depPending.length === 0) {
+                // dependencies resolve complete
+                this.progress.clean();
+                return succ;
+            } else {
+                let sub = await run();
+                return succ.concat(sub);
+            }
+        };
+
+        return run();
+    }
+
     async $parse(dep) {
         if (dep.color === COLOR.COMPILED) return dep;
         if (dep.color === COLOR.CHANGED) dep.code = void(0);

packages/wxa-cli/src/tree-shake/config.js

@@ -0,0 +1,39 @@
+module.exports = {
+    // {
+    //    src: '', // 路径
+    //    content: '', // 文件内容（可选）
+    // },
+    entry: [],
+    resolveSrc: {
+        // '/a/b/c'，绝对路径根目录
+        // 例如src, '/a/b/c' 转换为 /src/a/b/b
+        root: 'src',
+        // {'@': 'src'}，路径别名
+        alias: {},
+        npm: 'node_modules',
+    },
+    commonJS: {
+        enable: false,
+        // 无法追踪动态引入的模块
+        // 如果有模块被动态引入，需要在这里设置该模块文件路径
+        // 将跳过对该文件的 tree shake
+        dynamicRequireTargets: [],
+        // 设置 exports 上的哪些属性不会被转换为 esm
+        // 默认值有 '__esModule'
+        ingoreKeys: ['__esModule'],
+    },
+    parseOptions: {
+        plugins: [
+            ['decorators', {decoratorsBeforeExport: true}],
+            'classProperties',
+            'exportNamespaceFrom',
+            'exportDefaultFrom',
+            'objectRestSpread',
+        ],
+        sourceType: 'unambiguous',
+    },
+    generateOptions: {
+        decoratorsBeforeExport: true,
+    },
+    debug: false,
+};