fix(parser): store lone surrogates as escape sequence

crates/oxc_ast/src/ast/literal.rs

@@ -85,10 +85,14 @@ pub struct StringLiteral<'a> {
     #[content_eq(skip)]
     pub raw: Option<Atom<'a>>,
 
-    /// The string value contains replacement character (U+FFFD).
+    /// The string value contains lone surrogates.
+    ///
+    /// `value` is encoded using `\u{FFFD}` (the lossy replacement character) as an escape character.
+    /// Lone surrogates are encoded as `\u{FFFD}XXXX`, where `XXXX` is the code unit in hex.
+    /// The lossy escape character itself is encoded as `\u{FFFD}fffd`.
     #[builder(default)]
     #[estree(skip)]
-    pub lossy: bool,
+    pub lone_surrogates: bool,
 }
 
 /// BigInt literal

crates/oxc_ast/src/generated/assert_layouts.rs

@@ -776,7 +776,7 @@ const _: () = {
     assert!(offset_of!(StringLiteral, span) == 0);
     assert!(offset_of!(StringLiteral, value) == 8);
     assert!(offset_of!(StringLiteral, raw) == 24);
-    assert!(offset_of!(StringLiteral, lossy) == 40);
+    assert!(offset_of!(StringLiteral, lone_surrogates) == 40);
 
     assert!(size_of::<BigIntLiteral>() == 32);
     assert!(align_of::<BigIntLiteral>() == 8);
@@ -2167,7 +2167,7 @@ const _: () = {
     assert!(offset_of!(StringLiteral, span) == 0);
     assert!(offset_of!(StringLiteral, value) == 8);
     assert!(offset_of!(StringLiteral, raw) == 16);
-    assert!(offset_of!(StringLiteral, lossy) == 24);
+    assert!(offset_of!(StringLiteral, lone_surrogates) == 24);
 
     assert!(size_of::<BigIntLiteral>() == 20);
     assert!(align_of::<BigIntLiteral>() == 4);

crates/oxc_ast/src/generated/ast_builder.rs

@@ -276,27 +276,32 @@ impl<'a> AstBuilder<'a> {
         Expression::StringLiteral(self.alloc_string_literal(span, value, raw))
     }
 
-    /// Build an [`Expression::StringLiteral`] with `lossy`.
+    /// Build an [`Expression::StringLiteral`] with `lone_surrogates`.
     ///
     /// This node contains a [`StringLiteral`] that will be stored in the memory arena.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn expression_string_literal_with_lossy<A>(
+    pub fn expression_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> Expression<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        Expression::StringLiteral(self.alloc_string_literal_with_lossy(span, value, raw, lossy))
+        Expression::StringLiteral(self.alloc_string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build an [`Expression::TemplateLiteral`].
@@ -7843,25 +7848,30 @@ impl<'a> AstBuilder<'a> {
         ImportAttributeKey::StringLiteral(self.string_literal(span, value, raw))
     }
 
-    /// Build an [`ImportAttributeKey::StringLiteral`] with `lossy`.
+    /// Build an [`ImportAttributeKey::StringLiteral`] with `lone_surrogates`.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn import_attribute_key_string_literal_with_lossy<A>(
+    pub fn import_attribute_key_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> ImportAttributeKey<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        ImportAttributeKey::StringLiteral(self.string_literal_with_lossy(span, value, raw, lossy))
+        ImportAttributeKey::StringLiteral(self.string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build an [`ExportNamedDeclaration`].
@@ -8442,25 +8452,30 @@ impl<'a> AstBuilder<'a> {
         ModuleExportName::StringLiteral(self.string_literal(span, value, raw))
     }
 
-    /// Build a [`ModuleExportName::StringLiteral`] with `lossy`.
+    /// Build a [`ModuleExportName::StringLiteral`] with `lone_surrogates`.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn module_export_name_string_literal_with_lossy<A>(
+    pub fn module_export_name_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> ModuleExportName<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        ModuleExportName::StringLiteral(self.string_literal_with_lossy(span, value, raw, lossy))
+        ModuleExportName::StringLiteral(self.string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build a [`V8IntrinsicExpression`].
@@ -8598,7 +8613,12 @@ impl<'a> AstBuilder<'a> {
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        StringLiteral { span, value: value.into_in(self.allocator), raw, lossy: Default::default() }
+        StringLiteral {
+            span,
+            value: value.into_in(self.allocator),
+            raw,
+            lone_surrogates: Default::default(),
+        }
     }
 
     /// Build a [`StringLiteral`], and store it in the memory arena.
@@ -8622,50 +8642,53 @@ impl<'a> AstBuilder<'a> {
         Box::new_in(self.string_literal(span, value, raw), self.allocator)
     }
 
-    /// Build a [`StringLiteral`] with `lossy`.
+    /// Build a [`StringLiteral`] with `lone_surrogates`.
     ///
-    /// If you want the built node to be allocated in the memory arena, use [`AstBuilder::alloc_string_literal_with_lossy`] instead.
+    /// If you want the built node to be allocated in the memory arena, use [`AstBuilder::alloc_string_literal_with_lone_surrogates`] instead.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn string_literal_with_lossy<A>(
+    pub fn string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> StringLiteral<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        StringLiteral { span, value: value.into_in(self.allocator), raw, lossy }
+        StringLiteral { span, value: value.into_in(self.allocator), raw, lone_surrogates }
     }
 
-    /// Build a [`StringLiteral`] with `lossy`, and store it in the memory arena.
+    /// Build a [`StringLiteral`] with `lone_surrogates`, and store it in the memory arena.
     ///
-    /// Returns a [`Box`] containing the newly-allocated node. If you want a stack-allocated node, use [`AstBuilder::string_literal_with_lossy`] instead.
+    /// Returns a [`Box`] containing the newly-allocated node. If you want a stack-allocated node, use [`AstBuilder::string_literal_with_lone_surrogates`] instead.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn alloc_string_literal_with_lossy<A>(
+    pub fn alloc_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> Box<'a, StringLiteral<'a>>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        Box::new_in(self.string_literal_with_lossy(span, value, raw, lossy), self.allocator)
+        Box::new_in(
+            self.string_literal_with_lone_surrogates(span, value, raw, lone_surrogates),
+            self.allocator,
+        )
     }
 
     /// Build a [`BigIntLiteral`].
@@ -9444,29 +9467,32 @@ impl<'a> AstBuilder<'a> {
         JSXAttributeValue::StringLiteral(self.alloc_string_literal(span, value, raw))
     }
 
-    /// Build a [`JSXAttributeValue::StringLiteral`] with `lossy`.
+    /// Build a [`JSXAttributeValue::StringLiteral`] with `lone_surrogates`.
     ///
     /// This node contains a [`StringLiteral`] that will be stored in the memory arena.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn jsx_attribute_value_string_literal_with_lossy<A>(
+    pub fn jsx_attribute_value_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> JSXAttributeValue<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        JSXAttributeValue::StringLiteral(
-            self.alloc_string_literal_with_lossy(span, value, raw, lossy),
-        )
+        JSXAttributeValue::StringLiteral(self.alloc_string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build a [`JSXAttributeValue::ExpressionContainer`].
@@ -9949,27 +9975,32 @@ impl<'a> AstBuilder<'a> {
         TSEnumMemberName::String(self.alloc_string_literal(span, value, raw))
     }
 
-    /// Build a [`TSEnumMemberName::String`] with `lossy`.
+    /// Build a [`TSEnumMemberName::String`] with `lone_surrogates`.
     ///
     /// This node contains a [`StringLiteral`] that will be stored in the memory arena.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn ts_enum_member_name_string_with_lossy<A>(
+    pub fn ts_enum_member_name_string_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> TSEnumMemberName<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        TSEnumMemberName::String(self.alloc_string_literal_with_lossy(span, value, raw, lossy))
+        TSEnumMemberName::String(self.alloc_string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build a [`TSTypeAnnotation`].
@@ -10106,27 +10137,32 @@ impl<'a> AstBuilder<'a> {
         TSLiteral::StringLiteral(self.alloc_string_literal(span, value, raw))
     }
 
-    /// Build a [`TSLiteral::StringLiteral`] with `lossy`.
+    /// Build a [`TSLiteral::StringLiteral`] with `lone_surrogates`.
     ///
     /// This node contains a [`StringLiteral`] that will be stored in the memory arena.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn ts_literal_string_literal_with_lossy<A>(
+    pub fn ts_literal_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> TSLiteral<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        TSLiteral::StringLiteral(self.alloc_string_literal_with_lossy(span, value, raw, lossy))
+        TSLiteral::StringLiteral(self.alloc_string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build a [`TSLiteral::TemplateLiteral`].
@@ -13387,27 +13423,30 @@ impl<'a> AstBuilder<'a> {
         TSModuleDeclarationName::StringLiteral(self.string_literal(span, value, raw))
     }
 
-    /// Build a [`TSModuleDeclarationName::StringLiteral`] with `lossy`.
+    /// Build a [`TSModuleDeclarationName::StringLiteral`] with `lone_surrogates`.
     ///
     /// ## Parameters
     /// * `span`: Node location in source code
     /// * `value`: The value of the string.
     /// * `raw`: The raw string as it appears in source code.
-    /// * `lossy`: The string value contains replacement character (U+FFFD).
+    /// * `lone_surrogates`: The string value contains lone surrogates.
     #[inline]
-    pub fn ts_module_declaration_name_string_literal_with_lossy<A>(
+    pub fn ts_module_declaration_name_string_literal_with_lone_surrogates<A>(
         self,
         span: Span,
         value: A,
         raw: Option<Atom<'a>>,
-        lossy: bool,
+        lone_surrogates: bool,
     ) -> TSModuleDeclarationName<'a>
     where
         A: IntoIn<'a, Atom<'a>>,
     {
-        TSModuleDeclarationName::StringLiteral(
-            self.string_literal_with_lossy(span, value, raw, lossy),
-        )
+        TSModuleDeclarationName::StringLiteral(self.string_literal_with_lone_surrogates(
+            span,
+            value,
+            raw,
+            lone_surrogates,
+        ))
     }
 
     /// Build a [`TSModuleDeclarationBody::TSModuleDeclaration`].

crates/oxc_ast/src/generated/derive_clone_in.rs

@@ -4843,7 +4843,7 @@ impl<'new_alloc> CloneIn<'new_alloc> for StringLiteral<'_> {
             span: CloneIn::clone_in(&self.span, allocator),
             value: CloneIn::clone_in(&self.value, allocator),
             raw: CloneIn::clone_in(&self.raw, allocator),
-            lossy: CloneIn::clone_in(&self.lossy, allocator),
+            lone_surrogates: CloneIn::clone_in(&self.lone_surrogates, allocator),
         }
     }
 
@@ -4852,7 +4852,7 @@ impl<'new_alloc> CloneIn<'new_alloc> for StringLiteral<'_> {
             span: CloneIn::clone_in_with_semantic_ids(&self.span, allocator),
             value: CloneIn::clone_in_with_semantic_ids(&self.value, allocator),
             raw: CloneIn::clone_in_with_semantic_ids(&self.raw, allocator),
-            lossy: CloneIn::clone_in_with_semantic_ids(&self.lossy, allocator),
+            lone_surrogates: CloneIn::clone_in_with_semantic_ids(&self.lone_surrogates, allocator),
         }
     }
 }