Treeshake option

.api/public.d.ts

@@ -27,6 +27,22 @@ declare module "@cocos/ccbuild" {
          */
         function enumerateAllDependents(meta: buildEngine.Result, featureUnits: string[]): string[];
         export type ModuleFormat = "esm" | "cjs" | "system" | "iife";
+        export type HasModuleSideEffects = (id: string, external: boolean) => boolean;
+        export type ModuleSideEffectsOption = boolean | "no-external" | string[] | HasModuleSideEffects;
+        export type TreeshakingPreset = "smallest" | "safest" | "recommended";
+        export interface NormalizedTreeshakingOptions {
+            annotations: boolean;
+            correctVarValueBeforeDeclaration: boolean;
+            manualPureFunctions: readonly string[];
+            moduleSideEffects: HasModuleSideEffects;
+            propertyReadSideEffects: boolean | "always";
+            tryCatchDeoptimization: boolean;
+            unknownGlobalSideEffects: boolean;
+        }
+        export interface TreeshakingOptions extends Partial<Omit<NormalizedTreeshakingOptions, "moduleSideEffects">> {
+            moduleSideEffects?: ModuleSideEffectsOption;
+            preset?: TreeshakingPreset;
+        }
         export interface Options {
             /**
              * 引擎仓库目录。
@@ -162,6 +178,7 @@ declare module "@cocos/ccbuild" {
              * @note It's only avaiable when options.moduleFormat is 'system'.
              */
             enableNamedRegisterForSystemJSModuleFormat?: boolean;
+            treeshake?: TreeshakingOptions;
         }
         export interface Result {
             /**

modules/build-engine/src/engine-js/index.ts

@@ -402,6 +402,10 @@ export async function buildJsEngine(options: Required<buildEngine.Options>): Pro
         onwarn: rollupWarningHandler,
     };
 
+    if (options.treeshake) {
+        rollupOptions.treeshake = options.treeshake;
+    }
+
     const perf = true;
 
     if (perf) {

modules/build-engine/src/index.ts

@@ -69,6 +69,27 @@ export async function buildEngine (options: buildEngine.Options): Promise<buildE
  */
 export namespace buildEngine {
     export type ModuleFormat = 'esm' | 'cjs' | 'system' | 'iife';
+
+    export type HasModuleSideEffects = (id: string, external: boolean) => boolean;
+    export type ModuleSideEffectsOption = boolean | 'no-external' | string[] | HasModuleSideEffects;
+
+    export type TreeshakingPreset = 'smallest' | 'safest' | 'recommended';
+
+    export interface NormalizedTreeshakingOptions {
+        annotations: boolean;
+        correctVarValueBeforeDeclaration: boolean;
+        manualPureFunctions: readonly string[];
+        moduleSideEffects: HasModuleSideEffects;
+        propertyReadSideEffects: boolean | 'always';
+        tryCatchDeoptimization: boolean;
+        unknownGlobalSideEffects: boolean;
+    }
+
+    // See https://rollupjs.org/configuration-options/#treeshake for more details.
+    export interface TreeshakingOptions extends Partial<Omit<NormalizedTreeshakingOptions, 'moduleSideEffects'>> {
+        moduleSideEffects?: ModuleSideEffectsOption;
+        preset?: TreeshakingPreset;
+    }
 
     export interface Options {
         /**
@@ -237,6 +258,8 @@ export namespace buildEngine {
          * @note It's only avaiable when options.moduleFormat is 'system'.
          */
         enableNamedRegisterForSystemJSModuleFormat?: boolean;
+
+        treeshake?: TreeshakingOptions;
     }
 
     export interface Result {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@cocos/ccbuild",
-  "version": "2.2.12",
+  "version": "2.2.13",
   "description": "The next generation of build tool for Cocos engine.",
   "main": "./lib/index.js",
   "types": "./lib/index.d.ts",

scripts/test-build-cocos.js

@@ -15,6 +15,11 @@ const argv = process.argv;
 
     const outDir = ps.join(__dirname, '..', 'build-cc-out');
 
+    const noSideEffectFiles = [
+        'instantiate-jit.ts',
+        'splash-screen.ts',
+    ];
+
     const options = {
         "engine": enginePath,
         "out": outDir,
@@ -27,18 +32,31 @@ const argv = process.argv;
         "noDeprecatedFeatures": true,
         "sourceMap": false,
         // "features": ["2d", "3d", "animation", "audio", "base", "debug-renderer", "dragon-bones", "geometry-renderer", "gfx-webgl", "intersection-2d", "legacy-pipeline", "light-probe", "particle", "particle-2d", "physics-2d-builtin", "physics-cannon", "primitive", "profiler", "skeletal-animation", "spine", "terrain", "tiled-map", "tween", "ui", "video", "websocket", "webview"],
-        "features":["gfx-webgl2"],
+        // "features":["gfx-webgl2"],
+        "features": ["2d","audio","base","gfx-webgl2","legacy-pipeline","ui"], //,"animation","spine","tween"
+        // "features":["base", "audio", "2d", "ui", "gfx-webgl2"],
         "loose": true,
         "mode": "BUILD",
         "flags": {
             "DEBUG": false,
+            ONLY_2D: true,
             "WEBGPU": false
         },
         // "metaFile": ps.join(outDir, "meta.json"),
         // "incremental": ps.join(outDir, "watch-files.json"),
-        "wasmCompressionMode": false,
+        "wasmCompressionMode": 'brotli',
         "visualize": true,
         "inlineEnum": true,
+        treeshake: {
+            moduleSideEffects: (id, isExternal) => {
+                const fileName = ps.basename(id);
+                if (noSideEffectFiles.indexOf(fileName) >= 0) {
+                    console.info(`--> Found fileName: ${fileName}`);
+                    return false;
+                }
+                return true;
+            }
+        },
     };
 
     await ensureDir(outDir);