fix(es/module): Handle directives (#8048)

**Related issue:**

 - Closes: #8047

crates/swc_ecma_transforms_module/src/amd.rs

@@ -20,8 +20,8 @@ use crate::{
     module_ref_rewriter::{ImportMap, ModuleRefRewriter},
     path::{ImportResolver, Resolver},
     util::{
-        clone_first_use_directive, define_es_module, emit_export_stmts, local_name_for_src,
-        use_strict, ImportInterop,
+        define_es_module, emit_export_stmts, local_name_for_src, use_strict, ImportInterop,
+        VecStmtLike,
     },
 };
 
@@ -143,9 +143,19 @@ where
 
         let mut stmts: Vec<Stmt> = Vec::with_capacity(n.body.len() + 4);
 
+        // Collect directives
+        stmts.extend(
+            &mut n
+                .body
+                .iter_mut()
+                .take_while(|i| i.directive_continue())
+                .map(|i| i.take())
+                .map(ModuleItem::expect_stmt),
+        );
+
         // "use strict";
-        if self.config.strict_mode {
-            stmts.push(clone_first_use_directive(&n.body, true).unwrap_or_else(use_strict));
+        if self.config.strict_mode && !stmts.has_use_strict() {
+            stmts.push(use_strict());
         }
 
         let ModuleDeclStrip {
@@ -170,7 +180,7 @@ where
         );
 
         stmts.extend(n.body.take().into_iter().filter_map(|item| match item {
-            ModuleItem::Stmt(stmt) if !stmt.is_directive() => Some(stmt),
+            ModuleItem::Stmt(stmt) if !stmt.is_empty() => 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_directive, define_es_module, emit_export_stmts, local_name_for_src,
-        prop_name, use_strict, ImportInterop, ObjPropKeyIdent,
+        define_es_module, emit_export_stmts, local_name_for_src, prop_name, use_strict,
+        ImportInterop, ObjPropKeyIdent, VecStmtLike,
     },
 };
 
@@ -113,15 +113,18 @@ where
 
         let mut stmts: Vec<ModuleItem> = Vec::with_capacity(n.body.len() + 6);
 
-        stmts.extend(clone_first_use_directive(&n.body, false).map(From::from));
+        // Collect directives
+        stmts.extend(
+            &mut n
+                .body
+                .iter_mut()
+                .take_while(|i| i.directive_continue())
+                .map(|i| i.take()),
+        );
 
         // "use strict";
-        if self.config.strict_mode {
-            stmts.push(
-                clone_first_use_directive(&n.body, true)
-                    .unwrap_or_else(use_strict)
-                    .into(),
-            );
+        if self.config.strict_mode && !stmts.has_use_strict() {
+            stmts.push(use_strict().into());
         }
 
         let ModuleDeclStrip {
@@ -156,7 +159,7 @@ where
         );
 
         stmts.extend(n.body.take().into_iter().filter(|item| match item {
-            ModuleItem::Stmt(stmt) => !stmt.is_directive(),
+            ModuleItem::Stmt(stmt) => !stmt.is_empty(),
             _ => false,
         }));
 

crates/swc_ecma_transforms_module/src/umd.rs

@@ -17,8 +17,8 @@ use crate::{
     module_ref_rewriter::{ImportMap, ModuleRefRewriter},
     path::{ImportResolver, Resolver},
     util::{
-        clone_first_use_directive, define_es_module, emit_export_stmts, local_name_for_src,
-        use_strict, ImportInterop,
+        define_es_module, emit_export_stmts, local_name_for_src, use_strict, ImportInterop,
+        VecStmtLike,
     },
 };
 
@@ -116,9 +116,18 @@ where
 
         let mut stmts: Vec<Stmt> = Vec::with_capacity(module_items.len() + 4);
 
+        // Collect directives
+        stmts.extend(
+            module_items
+                .iter_mut()
+                .take_while(|i| i.directive_continue())
+                .map(|i| i.take())
+                .map(ModuleItem::expect_stmt),
+        );
+
         // "use strict";
-        if self.config.config.strict_mode {
-            stmts.push(clone_first_use_directive(module_items, true).unwrap_or_else(use_strict));
+        if self.config.config.strict_mode && !stmts.has_use_strict() {
+            stmts.push(use_strict());
         }
 
         let ModuleDeclStrip {
@@ -143,7 +152,7 @@ where
         );
 
         stmts.extend(module_items.take().into_iter().filter_map(|i| match i {
-            ModuleItem::Stmt(stmt) if !stmt.is_directive() => Some(stmt),
+            ModuleItem::Stmt(stmt) if !stmt.is_empty() => Some(stmt),
             _ => None,
         }));
 

crates/swc_ecma_transforms_module/src/util.rs

@@ -194,26 +194,33 @@ pub(super) fn define_es_module(exports: Ident) -> Stmt {
     .into_stmt()
 }
 
-pub(super) fn clone_first_use_directive(
-    stmts: &[ModuleItem],
-    want_use_strict: bool,
-) -> Option<Stmt> {
-    if stmts.is_empty() {
-        return None;
-    }
+pub(super) trait VecStmtLike {
+    type StmtLike: IsDirective;
 
-    stmts.iter().find_map(|item| match item {
-        ModuleItem::Stmt(stmt) => {
-            if (want_use_strict && stmt.is_use_strict())
-                || (!want_use_strict && !stmt.is_use_strict() && stmt.is_directive())
-            {
-                Some(stmt.clone())
-            } else {
-                None
-            }
-        }
-        _ => None,
-    })
+    fn as_ref(&self) -> &[Self::StmtLike];
+
+    fn has_use_strict(&self) -> bool {
+        self.as_ref()
+            .iter()
+            .take_while(|s| s.directive_continue())
+            .any(IsDirective::is_use_strict)
+    }
+}
+
+impl VecStmtLike for [ModuleItem] {
+    type StmtLike = ModuleItem;
+
+    fn as_ref(&self) -> &[Self::StmtLike] {
+        self
+    }
+}
+
+impl VecStmtLike for [Stmt] {
+    type StmtLike = Stmt;
+
+    fn as_ref(&self) -> &[Self::StmtLike] {
+        self
+    }
 }
 
 pub(super) fn use_strict() -> Stmt {

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

@@ -3,6 +3,7 @@ define([
     "require",
     "exports"
 ], function(require, exports) {
+    "use client";
     "use strict";
     Object.defineProperty(exports, "__esModule", {
         value: true

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

@@ -6,6 +6,7 @@
     ], factory);
     else if (global = typeof globalThis !== "undefined" ? globalThis : global || self) factory(global.input = {});
 })(this, function(exports) {
+    "use client";
     "use strict";
     Object.defineProperty(exports, "__esModule", {
         value: true

crates/swc_ecma_transforms_module/tests/fixture/common/issue-8047/input.js

@@ -0,0 +1,12 @@
+"use client";
+
+"foo";
+
+"use bar";
+
+"use strict";
+// All above are directives
+
+function foo() { }
+
+"use hello"; // This is not directive

crates/swc_ecma_transforms_module/tests/fixture/common/issue-8047/output.amd.js

@@ -0,0 +1,11 @@
+define([
+    "require"
+], function(require) {
+    "use client";
+    "foo";
+    "use bar";
+    "use strict";
+    // All above are directives
+    function foo() {}
+    "use hello"; // This is not directive
+});

crates/swc_ecma_transforms_module/tests/fixture/common/issue-8047/output.cjs

@@ -0,0 +1,7 @@
+"use client";
+"foo";
+"use bar";
+"use strict";
+// All above are directives
+function foo() {}
+"use hello"; // This is not directive

crates/swc_ecma_transforms_module/tests/fixture/common/issue-8047/output.umd.js

@@ -0,0 +1,13 @@
+(function(global, factory) {
+    if (typeof module === "object" && typeof module.exports === "object") factory();
+    else if (typeof define === "function" && define.amd) define([], factory);
+    else if (global = typeof globalThis !== "undefined" ? globalThis : global || self) factory();
+})(this, function() {
+    "use client";
+    "foo";
+    "use bar";
+    "use strict";
+    // All above are directives
+    function foo() {}
+    "use hello"; // This is not directive
+});

crates/swc_ecma_utils/src/lib.rs

@@ -2262,6 +2262,7 @@ pub fn prepend_stmts<T: StmtLike>(
 
 pub trait IsDirective {
     fn as_ref(&self) -> Option<&Stmt>;
+    #[deprecated(note = "use directive_continue instead")]
     fn is_directive(&self) -> bool {
         match self.as_ref() {
             Some(Stmt::Expr(expr)) => match &*expr.expr {
@@ -2273,6 +2274,15 @@ pub trait IsDirective {
             _ => false,
         }
     }
+    fn directive_continue(&self) -> bool {
+        match self.as_ref() {
+            Some(Stmt::Expr(expr)) => match &*expr.expr {
+                Expr::Lit(Lit::Str(..)) => true,
+                _ => false,
+            },
+            _ => false,
+        }
+    }
     fn is_use_strict(&self) -> bool {
         match self.as_ref() {
             Some(Stmt::Expr(expr)) => match *expr.expr {
@@ -2292,6 +2302,18 @@ impl IsDirective for Stmt {
     }
 }
 
+impl IsDirective for ModuleItem {
+    fn as_ref(&self) -> Option<&Stmt> {
+        self.as_stmt()
+    }
+}
+
+impl IsDirective for &ModuleItem {
+    fn as_ref(&self) -> Option<&Stmt> {
+        self.as_stmt()
+    }
+}
+
 pub trait IdentExt {
     fn prefix(&self, prefix: &str) -> Ident;