fix: ASI in the concatenated module only when necessary

crates/rspack_core/src/concatenated_module.rs

@@ -51,6 +51,8 @@ use crate::{
 type ExportsDefinitionArgs = Vec<(String, String)>;
 define_hook!(ConcatenatedModuleExportsDefinitions: SyncSeriesBail(exports_definitions: &mut ExportsDefinitionArgs) -> bool);
 
+const CHARS_REQUIRING_SEMICOLON: [char; 5] = ['[', '(', '+', '-', '/'];
+
 #[derive(Debug, Default)]
 pub struct ConcatenatedModuleHooks {
   pub exports_definitions: ConcatenatedModuleExportsDefinitionsHook,
@@ -185,6 +187,7 @@ pub struct ConcatenatedModuleInfo {
   pub global_scope_ident: Vec<ConcatenatedModuleIdent>,
   pub idents: Vec<ConcatenatedModuleIdent>,
   pub binding_to_ref: HashMap<(Atom, SyntaxContext), Vec<ConcatenatedModuleIdent>>,
+  pub prefix_asi: bool,
 }
 
 #[derive(Debug, Clone)]
@@ -892,6 +895,14 @@ impl Module for ConcatenatedModule {
         let source = info.source.as_mut().expect("should have source");
         // range is extended by 2 chars to cover the appended "._"
         // https://github.com/webpack/webpack/blob/ac7e531436b0d47cd88451f497cdfd0dad41535d/lib/optimize/ConcatenatedModule.js#L1411-L1412
+
+        let add_prefix_asi =
+          matches!(final_name.chars().next(), Some(c) if CHARS_REQUIRING_SEMICOLON.contains(&c));
+
+        if add_prefix_asi {
+          info.prefix_asi = true;
+        }
+
         source.replace(low, high + 2, &final_name, None);
       }
     }
@@ -1166,12 +1177,13 @@ impl Module for ConcatenatedModule {
       match info {
         ModuleInfo::Concatenated(info) => {
           result.add(RawSource::from(
-            format!(
-              "\n;// CONCATENATED MODULE: {}\n",
-              module_readable_identifier
-            )
-            .as_str(),
+            format!("\n// CONCATENATED MODULE: {}\n", module_readable_identifier).as_str(),
           ));
+
+          if info.prefix_asi {
+            result.add(RawSource::from(";"));
+          }
+
           // https://github.com/webpack/webpack/blob/ac7e531436b0d47cd88451f497cdfd0dad41535d/lib/optimize/ConcatenatedModule.js#L1582
           result.add(info.source.clone().expect("should have source"));
 
@@ -1692,6 +1704,8 @@ impl ConcatenatedModule {
         .remove(&SourceType::JavaScript)
         .expect("should have javascript source");
       let source_code = source.source();
+      let prefix_asi =
+        matches!(source_code.chars().next(), Some(c) if CHARS_REQUIRING_SEMICOLON.contains(&c));
 
       let cm: Arc<swc_core::common::SourceMap> = Default::default();
       let fm = cm.new_source_file(
@@ -1752,6 +1766,7 @@ impl ConcatenatedModule {
       module_info.global_ctxt = global_ctxt;
       module_info.ast = Some(ast);
       module_info.runtime_requirements = runtime_requirements;
+      module_info.prefix_asi = prefix_asi;
       module_info.internal_source = Some(source);
       module_info.source = Some(result_source);
       module_info.chunk_init_fragments = chunk_init_fragments;

packages/rspack-test-tools/tests/__snapshots__/Config.test.js.snap

@@ -439,13 +439,13 @@ __webpack_require__.o = function (obj, prop) {
 })();
 /************************************************************************/
 
-;// CONCATENATED MODULE: ./e/foo.js
+// CONCATENATED MODULE: ./e/foo.js
 const foo = 'foo'
 
 // EXTERNAL MODULE: ./e/bar.cjs
 var bar = __webpack_require__(\\"997\\");
 var bar_default = /*#__PURE__*/__webpack_require__.n(bar);
-;// CONCATENATED MODULE: ./e/index.js
+// CONCATENATED MODULE: ./e/index.js
 
 
 
@@ -458,7 +458,7 @@ export { foo, __webpack_exports__bar as bar };
 
 exports[`config config/library/modern-module-force-concaten step  should pass: .mjs should concat 1`] = `
 "
-;// CONCATENATED MODULE: ./d.mjs
+// CONCATENATED MODULE: ./d.mjs
 const d = 'd'
 "
 `;
@@ -541,11 +541,11 @@ __webpack_require__.o = function (obj, prop) {
 // EXTERNAL MODULE: ./f/bar.cjs
 var bar = __webpack_require__(\\"441\\");
 var bar_default = /*#__PURE__*/__webpack_require__.n(bar);
-;// CONCATENATED MODULE: ./f/foo.js
+// CONCATENATED MODULE: ./f/foo.js
 const foo = 'foo'
 
-;// CONCATENATED MODULE: ./f/index.js
-
+// CONCATENATED MODULE: ./f/index.js
+;
 
 
 const value = foo + (bar_default())
@@ -558,7 +558,7 @@ export { value };
 
 exports[`config config/library/modern-module-force-concaten step  should pass: harmony export should concat 1`] = `
 "
-;// CONCATENATED MODULE: ./a.js
+// CONCATENATED MODULE: ./a.js
 const a = 'a'
 
 export { a };

packages/rspack-test-tools/tests/__snapshots__/StatsOutput.test.js.snap

@@ -78,7 +78,7 @@ Rspack compiled with 1 error"
 `;
 
 exports[`statsOutput statsOutput/concatenated-modules should print correct stats for 1`] = `
-"asset main.js 234 bytes [emitted] (name: main)
+"asset main.js 230 bytes [emitted] (name: main)
 orphan modules 141 bytes [orphan] 4 modules
 ./index.js + 3 modules 141 bytes [code generated]
 Rspack x.x.x compiled successfully in X s"
@@ -428,7 +428,7 @@ Rspack x.x.x compiled successfully in X s"
 `;
 
 exports[`statsOutput statsOutput/side-effects-bailouts should print correct stats for 1`] = `
-"asset main.js 177 bytes {909} [emitted] (name: main)
+"asset main.js 175 bytes {909} [emitted] (name: main)
 chunk {909} (runtime: main) main.js (main) 91 bytes [entry] [rendered]
 orphan modules 91 bytes [orphan] 2 modules
 ./index.js + 1 modules [911] 91 bytes {909} [code generated]

packages/rspack-test-tools/tests/builtinCases/samples/concatenate-modules/__snapshots__/output.snap.txt

@@ -3,10 +3,10 @@
 (self['webpackChunkwebpack'] = self['webpackChunkwebpack'] || []).push([["main"], {
 "./index.js": (function () {
 
-;// CONCATENATED MODULE: ./answer.js
+// CONCATENATED MODULE: ./answer.js
 const answer = 103330;
 
-;// CONCATENATED MODULE: ./index.js
+// CONCATENATED MODULE: ./index.js
 
 answer;
 

packages/rspack-test-tools/tests/hookCases/normalModuleFactory#afterResolve/request/output.snap.txt

@@ -81,11 +81,11 @@ var a_default = /*#__PURE__*/__webpack_require__.n(a);
 // EXTERNAL MODULE: ../../normalModuleFactory​#afterResolve/request/c.js
 var c = __webpack_require__("../../normalModuleFactory​#afterResolve/request/c.js");
 var c_default = /*#__PURE__*/__webpack_require__.n(c);
-;// CONCATENATED MODULE: external "fs"
+// CONCATENATED MODULE: external "fs"
 var external_fs_namespaceObject = require("fs");
 var external_fs_default = /*#__PURE__*/__webpack_require__.n(external_fs_namespaceObject);
-;// CONCATENATED MODULE: ../../normalModuleFactory​#afterResolve/request/request.js
-
+// CONCATENATED MODULE: ../../normalModuleFactory​#afterResolve/request/request.js
+;
 
 
 

packages/rspack-test-tools/tests/hookCases/normalModuleFactory#afterResolve/resource/output.snap.txt

@@ -81,11 +81,11 @@ var a_default = /*#__PURE__*/__webpack_require__.n(a);
 // EXTERNAL MODULE: ../../normalModuleFactory​#afterResolve/resource/b.js
 var b = __webpack_require__("../../normalModuleFactory​#afterResolve/resource/b.js");
 var b_default = /*#__PURE__*/__webpack_require__.n(b);
-;// CONCATENATED MODULE: external "fs"
+// CONCATENATED MODULE: external "fs"
 var external_fs_namespaceObject = require("fs");
 var external_fs_default = /*#__PURE__*/__webpack_require__.n(external_fs_namespaceObject);
-;// CONCATENATED MODULE: ../../normalModuleFactory​#afterResolve/resource/resource.js
-
+// CONCATENATED MODULE: ../../normalModuleFactory​#afterResolve/resource/resource.js
+;
 
 
 

packages/rspack-test-tools/tests/hookCases/normalModuleFactory#resolve/resource/output.snap.txt

@@ -81,11 +81,11 @@ var a_default = /*#__PURE__*/__webpack_require__.n(a);
 // EXTERNAL MODULE: ../../normalModuleFactory​#resolve/resource/b.js
 var b = __webpack_require__("../../normalModuleFactory​#resolve/resource/b.js");
 var b_default = /*#__PURE__*/__webpack_require__.n(b);
-;// CONCATENATED MODULE: external "fs"
+// CONCATENATED MODULE: external "fs"
 var external_fs_namespaceObject = require("fs");
 var external_fs_default = /*#__PURE__*/__webpack_require__.n(external_fs_namespaceObject);
-;// CONCATENATED MODULE: ../../normalModuleFactory​#resolve/resource/resource.js
-
+// CONCATENATED MODULE: ../../normalModuleFactory​#resolve/resource/resource.js
+;
 
 
 

packages/rspack-test-tools/tests/statsAPICases/asset-info.js

@@ -98,7 +98,7 @@ module.exports = {
 		    "isOverSizeLimit": false,
 		    "name": "main.js",
 		    "related": Array [],
-		    "size": 2763,
+		    "size": 2761,
 		    "type": "asset",
 		  },
 		]

tests/webpack-test/__snapshots__/StatsTestCases.basictest.js.snap

@@ -449,7 +449,7 @@ chunk (runtime: main) trees.js (trees) 215 bytes [rendered]
 `;
 
 exports[`StatsTestCases should print correct stats for ignore-warnings 1`] = `
-"asset main.js 1.83 KiB [emitted] (name: main)
+"asset main.js 1.82 KiB [emitted] (name: main)
 orphan modules 794 bytes [orphan] 10 modules
 ./index.js + 9 modules 794 bytes [code generated]
 Rspack x.x.x compiled successfully in X.23"
@@ -904,7 +904,7 @@ Rspack x.x.x compiled successfully in X.23"
 `;
 
 exports[`StatsTestCases should print correct stats for parse-error 1`] = `
-"assets by status 1.41 KiB [cached] 1 asset
+"assets by status 1.4 KiB [cached] 1 asset
 orphan modules 30 bytes [orphan] 2 modules
 cacheable modules 85 bytes
   ./index.js + 1 modules 30 bytes [code generated]
@@ -1628,7 +1628,7 @@ Rspack x.x.x compiled successfully in X.23"
 `;
 
 exports[`StatsTestCases should print correct stats for side-effects-simple-unused 1`] = `
-"asset main.js 297 bytes [emitted] (name: main)
+"asset main.js 294 bytes [emitted] (name: main)
 modules by path ./node_modules/pmodule/*.js 232 bytes
   ./node_modules/pmodule/index.js 75 bytes [orphan] [built]
     [only some exports used: default]
@@ -2278,8 +2278,8 @@ exports[`StatsTestCases should print correct stats for split-chunks-runtime-spec
   asset used-exports-c.js 4.6 KiB [emitted] (name: c)
   asset used-exports-b.js 4.6 KiB [emitted] (name: b)
   asset used-exports-572.js 370 bytes [emitted]
-  asset used-exports-a.js 249 bytes [emitted] (name: a)
-  Entrypoint a 249 bytes = used-exports-a.js
+  asset used-exports-a.js 247 bytes [emitted] (name: a)
+  Entrypoint a 247 bytes = used-exports-a.js
   Entrypoint b 4.96 KiB = used-exports-572.js 370 bytes used-exports-b.js 4.6 KiB
   Entrypoint c 4.96 KiB = used-exports-572.js 370 bytes used-exports-c.js 4.6 KiB
   chunk (runtime: b, c) used-exports-572.js (id hint: ) 72 bytes [initial] [rendered] split chunk (cache group: default)

tests/webpack-test/configCases/scope-hoisting/issue-11897/webpack.config.js

@@ -0,0 +1,6 @@
+/** @type {import("@rspack/core").Configuration} */
+module.exports = {
+	optimization: {
+		concatenateModules: true
+	}
+};