feat(es/module): Preserve custom use directives (#7528)

**Related issue:**

 - Closes #7315.

Author: kdy1

crates/swc/tests/fixture/issues-7xxx/7315/1/input/.swcrc

@@ -0,0 +1,5 @@
+{
+    "module": {
+        "type": "commonjs"
+    }
+}

crates/swc/tests/fixture/issues-7xxx/7315/1/input/index.js

@@ -0,0 +1,6 @@
+// input.ts
+"use client"
+
+export function ReactClientComponent() {
+    return "Hello world"
+}

crates/swc/tests/fixture/issues-7xxx/7315/1/output/index.js

@@ -0,0 +1,14 @@
+// input.ts
+"use client";
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+Object.defineProperty(exports, "ReactClientComponent", {
+    enumerable: true,
+    get: function() {
+        return ReactClientComponent;
+    }
+});
+function ReactClientComponent() {
+    return "Hello world";
+}

crates/swc_ecma_transforms_module/src/amd.rs

@@ -20,7 +20,7 @@ use crate::{
     module_ref_rewriter::{ImportMap, ModuleRefRewriter},
     path::{ImportResolver, Resolver},
     util::{
-        clone_first_use_strict, define_es_module, emit_export_stmts, local_name_for_src,
+        clone_first_use_directive, define_es_module, emit_export_stmts, local_name_for_src,
         use_strict, ImportInterop,
     },
 };
@@ -145,7 +145,7 @@ where
 
         // "use strict";
         if self.config.strict_mode {
-            stmts.push(clone_first_use_strict(n).unwrap_or_else(use_strict));
+            stmts.push(clone_first_use_directive(n).unwrap_or_else(use_strict));
         }
 
         let ModuleDeclStrip {
@@ -170,7 +170,7 @@ where
         );
 
         stmts.extend(n.take().into_iter().filter_map(|item| match item {
-            ModuleItem::Stmt(stmt) if !stmt.is_use_strict() => Some(stmt),
+            ModuleItem::Stmt(stmt) if !stmt.is_directive() => Some(stmt),
             _ => None,
         }));
 

crates/swc_ecma_transforms_module/src/common_js.rs

@@ -16,8 +16,8 @@ use crate::{
     module_ref_rewriter::{ImportMap, ModuleRefRewriter},
     path::{ImportResolver, Resolver},
     util::{
-        clone_first_use_strict, define_es_module, emit_export_stmts, local_name_for_src, prop_name,
-        use_strict, ImportInterop, ObjPropKeyIdent,
+        clone_first_use_directive, define_es_module, emit_export_stmts, local_name_for_src,
+        prop_name, use_strict, ImportInterop, ObjPropKeyIdent,
     },
 };
 
@@ -115,7 +115,11 @@ where
 
         // "use strict";
         if self.config.strict_mode {
-            stmts.push(clone_first_use_strict(n).unwrap_or_else(use_strict).into());
+            stmts.push(
+                clone_first_use_directive(n)
+                    .unwrap_or_else(use_strict)
+                    .into(),
+            );
         }
 
         let ModuleDeclStrip {
@@ -150,7 +154,7 @@ where
         );
 
         stmts.extend(n.take().into_iter().filter(|item| match item {
-            ModuleItem::Stmt(stmt) => !stmt.is_use_strict(),
+            ModuleItem::Stmt(stmt) => !stmt.is_directive(),
             _ => false,
         }));
 

crates/swc_ecma_transforms_module/src/umd.rs

@@ -18,7 +18,7 @@ use crate::{
     module_ref_rewriter::{ImportMap, ModuleRefRewriter},
     path::{ImportResolver, Resolver},
     util::{
-        clone_first_use_strict, define_es_module, emit_export_stmts, local_name_for_src,
+        clone_first_use_directive, define_es_module, emit_export_stmts, local_name_for_src,
         use_strict, ImportInterop,
     },
 };
@@ -122,7 +122,7 @@ where
 
         // "use strict";
         if self.config.config.strict_mode {
-            stmts.push(clone_first_use_strict(module_items).unwrap_or_else(use_strict));
+            stmts.push(clone_first_use_directive(module_items).unwrap_or_else(use_strict));
         }
 
         let ModuleDeclStrip {
@@ -147,7 +147,7 @@ where
         );
 
         stmts.extend(module_items.take().into_iter().filter_map(|i| match i {
-            ModuleItem::Stmt(stmt) if !stmt.is_use_strict() => Some(stmt),
+            ModuleItem::Stmt(stmt) if !stmt.is_directive() => Some(stmt),
             _ => None,
         }));
 

crates/swc_ecma_transforms_module/src/util.rs

@@ -190,14 +190,14 @@ pub(super) fn define_es_module(exports: Ident) -> Stmt {
     .into_stmt()
 }
 
-pub(super) fn clone_first_use_strict(stmts: &[ModuleItem]) -> Option<Stmt> {
+pub(super) fn clone_first_use_directive(stmts: &[ModuleItem]) -> Option<Stmt> {
     if stmts.is_empty() {
         return None;
     }
 
     stmts.iter().find_map(|item| match item {
         ModuleItem::Stmt(stmt @ Stmt::Expr(ExprStmt { expr, .. })) => match **expr {
-            Expr::Lit(Lit::Str(Str { ref value, .. })) if value == "use strict" => {
+            Expr::Lit(Lit::Str(Str { ref value, .. })) if value.starts_with("use ") => {
                 Some(stmt.clone())
             }
             _ => None,

crates/swc_ecma_transforms_module/tests/fixture/common/issue-7315/input.js

@@ -0,0 +1,6 @@
+// input.ts
+"use client"
+
+export function ReactClientComponent() {
+    return "Hello world"
+}

crates/swc_ecma_transforms_module/tests/fixture/common/issue-7315/output.amd.js

@@ -0,0 +1,19 @@
+// input.ts
+define([
+    "require",
+    "exports"
+], function(require, exports) {
+    "use client";
+    Object.defineProperty(exports, "__esModule", {
+        value: true
+    });
+    Object.defineProperty(exports, "ReactClientComponent", {
+        enumerable: true,
+        get: function() {
+            return ReactClientComponent;
+        }
+    });
+    function ReactClientComponent() {
+        return "Hello world";
+    }
+});

crates/swc_ecma_transforms_module/tests/fixture/common/issue-7315/output.cjs

@@ -0,0 +1,14 @@
+// input.ts
+"use client";
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+Object.defineProperty(exports, "ReactClientComponent", {
+    enumerable: true,
+    get: function() {
+        return ReactClientComponent;
+    }
+});
+function ReactClientComponent() {
+    return "Hello world";
+}

crates/swc_ecma_transforms_module/tests/fixture/common/issue-7315/output.umd.js

@@ -0,0 +1,22 @@
+// input.ts
+(function(global, factory) {
+    if (typeof module === "object" && typeof module.exports === "object") factory(exports);
+    else if (typeof define === "function" && define.amd) define([
+        "exports"
+    ], factory);
+    else if (global = typeof globalThis !== "undefined" ? globalThis : global || self) factory(global.input = {});
+})(this, function(exports) {
+    "use client";
+    Object.defineProperty(exports, "__esModule", {
+        value: true
+    });
+    Object.defineProperty(exports, "ReactClientComponent", {
+        enumerable: true,
+        get: function() {
+            return ReactClientComponent;
+        }
+    });
+    function ReactClientComponent() {
+        return "Hello world";
+    }
+});

crates/swc_ecma_utils/src/lib.rs

@@ -2267,6 +2267,17 @@ pub fn prepend_stmts<T: StmtLike>(
 
 pub trait IsDirective {
     fn as_ref(&self) -> Option<&Stmt>;
+    fn is_directive(&self) -> bool {
+        match self.as_ref() {
+            Some(Stmt::Expr(expr)) => match &*expr.expr {
+                Expr::Lit(Lit::Str(Str {
+                    raw: Some(value), ..
+                })) => value.starts_with("\"use ") || value.starts_with("'use "),
+                _ => false,
+            },
+            _ => false,
+        }
+    }
     fn is_use_strict(&self) -> bool {
         match self.as_ref() {
             Some(Stmt::Expr(expr)) => match *expr.expr {