fix(treeshaking): spreading an expression is consider having side eff…

…ect (#509)

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### Description

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### Test Plan

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---

crates/rolldown/src/ast_scanner/side_effect_detector.rs

@@ -123,8 +123,10 @@ impl<'a> SideEffectDetector<'a> {
 
             key_side_effect || prop_init_side_effect || value_side_effect
           }
-          oxc::ast::ast::ObjectPropertyKind::SpreadProperty(spread) => {
-            self.detect_side_effect_of_expr(&spread.argument)
+          oxc::ast::ast::ObjectPropertyKind::SpreadProperty(_) => {
+            // ...[expression] is considered as having side effect.
+            // see crates/rolldown/tests/fixtures/rollup/object-spread-side-effect
+            true
           }
         })
       }

crates/rolldown/tests/fixtures/rollup/object-spread-side-effect/artifacts.snap

@@ -0,0 +1,23 @@
+---
+source: crates/rolldown/tests/common/case.rs
+expression: content
+input_file: crates/rolldown/tests/fixtures/rollup/object-spread-side-effect
+---
+# Assets
+
+## main.mjs
+
+```js
+import { default as assert } from "assert";
+
+// main.js
+let result = 'FAIL';
+const unused = {
+	...{
+		get prop(){
+			result = 'PASS';
+		}
+	}
+};
+assert.strictEqual(result, 'PASS');
+```

crates/rolldown/tests/fixtures/rollup/object-spread-side-effect/main.js

@@ -0,0 +1,10 @@
+import assert from 'assert';
+let result = 'FAIL';
+const unused = {
+  ...{
+    get prop() {
+      result = 'PASS';
+    }
+  }
+};
+assert.strictEqual(result, 'PASS');

crates/rolldown/tests/fixtures/rollup/object-spread-side-effect/test.config.json

@@ -0,0 +1,7 @@
+{
+  "input": {
+    "external": [
+      "assert"
+    ]
+  }
+}

crates/rolldown_binding/index.d.ts

@@ -95,7 +95,11 @@ export interface SourceMap {
   sources: Array<string>
   sourcesContent: Array<string>
 }
-export interface OutputChunk {
+export interface BindingOutputAsset {
+  fileName: string
+  source: string
+}
+export interface BindingOutputChunk {
   isEntry: boolean
   isDynamicEntry: boolean
   facadeModuleId?: string
@@ -105,20 +109,16 @@ export interface OutputChunk {
   modules: Record<string, BindingRenderedModule>
   code: string
 }
-export interface OutputAsset {
-  fileName: string
-  source: string
-}
-export interface Outputs {
-  chunks: Array<OutputChunk>
-  assets: Array<OutputAsset>
+export interface BindingOutputs {
+  chunks: Array<BindingOutputChunk>
+  assets: Array<BindingOutputAsset>
 }
 export interface BindingRenderedModule {
   code?: string
 }
 export class Bundler {
   constructor(inputOpts: InputOptions)
-  write(opts: OutputOptions): Promise<Outputs>
-  generate(opts: OutputOptions): Promise<Outputs>
+  write(opts: OutputOptions): Promise<BindingOutputs>
+  generate(opts: OutputOptions): Promise<BindingOutputs>
   scan(): Promise<void>
 }

crates/rolldown_binding/src/options/input_options/mod.rs

@@ -138,7 +138,7 @@ impl From<InputOptions>
         input: value.input.into_iter().map(Into::into).collect::<Vec<_>>(),
         cwd,
         external,
-        treeshake: false,
+        treeshake: true,
         resolve: value.resolve.map(Into::into),
       }),
       value.plugins.into_iter().map(JsAdapterPlugin::new_boxed).collect::<napi::Result<Vec<_>>>(),

packages/node/src/options/create-build-plugin-adapter.ts

@@ -5,7 +5,7 @@ import type {
   ResolveIdResult,
   RenderedChunk,
   HookRenderChunkOutput,
-  Outputs,
+  BindingOutputs as Outputs,
 } from '@rolldown/node-binding'
 import { transformToOutputBundle, unimplemented, transformSourcemap } from '../utils'
 

packages/node/src/utils/transform-to-rollup-output.ts

@@ -1,8 +1,8 @@
-import { OutputAsset, OutputChunk, Outputs } from '@rolldown/node-binding'
 import { RolldownOutput, RolldownOutputAsset, RolldownOutputChunk } from '../objects/rolldown-output'
 import { OutputBundle } from '../objects/output-bundle'
+import { BindingOutputAsset, BindingOutputChunk, BindingOutputs } from '@rolldown/node-binding'
 
-function transformToRollupOutputChunk(chunk: OutputChunk): RolldownOutputChunk {
+function transformToRollupOutputChunk(chunk: BindingOutputChunk): RolldownOutputChunk {
   return {
     type: 'chunk',
     code: chunk.code,
@@ -17,15 +17,15 @@ function transformToRollupOutputChunk(chunk: OutputChunk): RolldownOutputChunk {
   }
 }
 
-function transformToRollupOutputAsset(asset: OutputAsset): RolldownOutputAsset {
+function transformToRollupOutputAsset(asset: BindingOutputAsset): RolldownOutputAsset {
   return {
     type: 'asset',
     fileName: asset.fileName,
     source: asset.source,
   }
 }
 
-export function transformToRollupOutput(output: Outputs): RolldownOutput {
+export function transformToRollupOutput(output: BindingOutputs): RolldownOutput {
   const { chunks, assets } = output
   const [firstChunk, ...restChunks] = chunks
   return {
@@ -38,7 +38,7 @@ export function transformToRollupOutput(output: Outputs): RolldownOutput {
 }
 
 
-export function transformToOutputBundle(output: Outputs): OutputBundle {
+export function transformToOutputBundle(output: BindingOutputs): OutputBundle {
   return Object.fromEntries(
     transformToRollupOutput(output).output.map((item) => [item.fileName, item]),
   )