Trait JavascriptParserPlugin 

pub trait JavascriptParserPlugin {
    // Provided methods
    fn implemented_hooks(&self) -> JavascriptParserPluginHooks { ... }
    fn pre_statement(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _stmt: Statement<'_>,
    ) -> Option<bool> { ... }
    fn block_pre_statement(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _stmt: Statement<'_>,
    ) -> Option<bool> { ... }
    fn top_level_await_expr(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &AwaitExpr,
    ) { ... }
    fn top_level_for_of_await_stmt(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _stmt: &ForOfStmt,
    ) { ... }
    fn can_rename(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _str: &str,
    ) -> Option<bool> { ... }
    fn rename(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &Expr,
        _str: &str,
    ) -> Option<bool> { ... }
    fn program(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _ast: &Program,
    ) -> Option<bool> { ... }
    fn statement(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _stmt: Statement<'_>,
    ) -> Option<bool> { ... }
    fn unused_statement(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _stmt: Statement<'_>,
    ) -> Option<bool> { ... }
    fn module_declaration(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _decl: &ModuleDecl,
    ) -> Option<bool> { ... }
    fn block_pre_module_declaration(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _decl: &ModuleDecl,
    ) -> Option<bool> { ... }
    fn pre_declarator(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _declarator: &VarDeclarator,
        _declaration: VariableDeclaration<'_>,
    ) -> Option<bool> { ... }
    fn evaluate<'a>(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &'a Expr,
    ) -> Option<BasicEvaluatedExpression<'a>> { ... }
    fn evaluate_typeof<'a>(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &'a UnaryExpr,
        _for_name: &str,
    ) -> Option<BasicEvaluatedExpression<'a>> { ... }
    fn evaluate_identifier(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _for_name: &str,
        _start: u32,
        _end: u32,
    ) -> Option<BasicEvaluatedExpression<'static>> { ... }
    fn evaluate_call_expression<'a>(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _name: &str,
        _expr: &'a CallExpr,
    ) -> Option<BasicEvaluatedExpression<'a>> { ... }
    fn evaluate_call_expression_member<'a>(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _property: &str,
        _expr: &'a CallExpr,
        _param: BasicEvaluatedExpression<'a>,
    ) -> Option<BasicEvaluatedExpression<'a>> { ... }
    fn can_collect_destructuring_assignment_properties(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &Expr,
    ) -> Option<bool> { ... }
    fn pattern(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _ident: &Ident,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn call(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &CallExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn call_member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &CallExpr,
        _for_name: &str,
        _members: &[Atom],
        _members_optionals: &[bool],
        _member_ranges: &[Span],
    ) -> Option<bool> { ... }
    fn member(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &MemberExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &MemberExpr,
        _for_name: &str,
        _members: &[Atom],
        _members_optionals: &[bool],
        _member_ranges: &[Span],
    ) -> Option<bool> { ... }
    fn unhandled_expression_member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _root_info: &ExportedVariableInfo,
        _expr: &MemberExpr,
    ) -> Option<bool> { ... }
    fn member_chain_of_call_member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _member_expr: &MemberExpr,
        _callee_members: &[Atom],
        _call_expr: &CallExpr,
        _members: &[Atom],
        _member_ranges: &[Span],
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn call_member_chain_of_call_member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _call_expr: &CallExpr,
        _callee_members: &[Atom],
        _inner_call_expr: &CallExpr,
        _members: &[Atom],
        _member_ranges: &[Span],
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn typeof(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &UnaryExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn expression_logical_operator(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &BinExpr,
    ) -> Option<bool> { ... }
    fn binary_expression(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &BinExpr,
    ) -> Option<bool> { ... }
    fn statement_if(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &IfStmt,
    ) -> Option<bool> { ... }
    fn class_extends_expression(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _super_class: &Expr,
        _class_decl_or_expr: ClassDeclOrExpr<'_>,
    ) -> Option<bool> { ... }
    fn class_body_element(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _element: &ClassMember,
        _class_decl_or_expr: ClassDeclOrExpr<'_>,
    ) -> Option<bool> { ... }
    fn class_body_value(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _element: &ClassMember,
        _expr_span: Span,
        _class_decl_or_expr: ClassDeclOrExpr<'_>,
    ) -> Option<bool> { ... }
    fn declarator(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &VarDeclarator,
        _stmt: VariableDeclaration<'_>,
    ) -> Option<bool> { ... }
    fn new_expression(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &NewExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn identifier(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _ident: &Ident,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn this(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &ThisExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn assign(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &AssignExpr,
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn assign_member_chain(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &AssignExpr,
        _members: &[Atom],
        _for_name: &str,
    ) -> Option<bool> { ... }
    fn import_call(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &CallExpr,
        _import_then: Option<&CallExpr>,
        _members: Option<(&[Atom], bool)>,
    ) -> Option<bool> { ... }
    fn meta_property(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _root_name: &Atom,
        _span: Span,
    ) -> Option<bool> { ... }
    fn import(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: &ImportDecl,
        _source: &str,
    ) -> Option<bool> { ... }
    fn import_specifier(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: &ImportDecl,
        _source: &Atom,
        _export_name: Option<&Atom>,
        _identifier_name: &Atom,
    ) -> Option<bool> { ... }
    fn export_import(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: ExportImport<'_>,
        _source: &Atom,
    ) -> Option<bool> { ... }
    fn export(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: ExportLocal<'_>,
    ) -> Option<bool> { ... }
    fn export_import_specifier(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: ExportImport<'_>,
        _source: &Atom,
        _local_id: Option<&Atom>,
        _export_name: Option<&Atom>,
        _export_name_span: Option<Span>,
    ) -> Option<bool> { ... }
    fn export_specifier(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: ExportLocal<'_>,
        _local_id: &Atom,
        _export_name: &Atom,
        _export_name_span: Span,
    ) -> Option<bool> { ... }
    fn export_expression(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _statement: ExportDefaultDeclaration<'_>,
        _expr: ExportDefaultExpression<'_>,
    ) -> Option<bool> { ... }
    fn optional_chaining(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &OptChainExpr,
    ) -> Option<bool> { ... }
    fn expression_conditional_operation(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &CondExpr,
    ) -> Option<bool> { ... }
    fn finish(&self, _parser: &mut JavascriptParser<'_>) -> Option<bool> { ... }
    fn is_pure(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _expr: &Expr,
    ) -> Option<bool> { ... }
    fn import_meta_property_in_destructuring(
        &self,
        _parser: &mut JavascriptParser<'_>,
        _property: &DestructuringAssignmentProperty,
    ) -> Option<String> { ... }
}

Provided Methods

fn implemented_hooks(&self) -> JavascriptParserPluginHooks

Used by the parser drive to precompute which hook paths this plugin actually implements.

Why this exists (performance)

JavaScriptParserPluginDrive needs to call many hook methods while walking the AST. Calling every hook on every plugin would be very expensive.

Instead, rspack precomputes a hook mask for each plugin at construction time:

• Each plugin reports which hooks it actually implements via this method.
• The drive groups plugins by hook up-front.
• During parsing, the drive only iterates plugins that declared the current hook.

This cuts a large amount of useless dynamic dispatch at runtime.

How to implement

Do NOT implement this method manually.

Use the proc-macro attribute #[rspack_plugin_javascript::implemented_javascript_parser_hooks] (or #[rspack_macros::implemented_javascript_parser_hooks] inside the workspace). The macro inspects the impl JavascriptParserPlugin for ... block and generates an efficient implemented_hooks implementation automatically.

fn pre_statement( &self, _parser: &mut JavascriptParser<'_>, _stmt: Statement<'_>, ) -> Option<bool>

Return:

• Some(true) signifies the termination of the current statement’s visit during the pre-walk phase.
• Other return values imply that the walk operation ought to continue

fn block_pre_statement( &self, _parser: &mut JavascriptParser<'_>, _stmt: Statement<'_>, ) -> Option<bool>

fn top_level_await_expr( &self, _parser: &mut JavascriptParser<'_>, _expr: &AwaitExpr, )

The return value will have no effect.

fn top_level_for_of_await_stmt( &self, _parser: &mut JavascriptParser<'_>, _stmt: &ForOfStmt, )

The return value will have no effect.

fn can_rename( &self, _parser: &mut JavascriptParser<'_>, _str: &str, ) -> Option<bool>

fn rename( &self, _parser: &mut JavascriptParser<'_>, _expr: &Expr, _str: &str, ) -> Option<bool>

fn program( &self, _parser: &mut JavascriptParser<'_>, _ast: &Program, ) -> Option<bool>

fn statement( &self, _parser: &mut JavascriptParser<'_>, _stmt: Statement<'_>, ) -> Option<bool>

fn unused_statement( &self, _parser: &mut JavascriptParser<'_>, _stmt: Statement<'_>, ) -> Option<bool>

Called for statements after a terminating point (when only function declarations should still be processed). Plugins may eliminate or transform such unused statements.

Return:

• Some(true) means the statement is fully handled and should be skipped
• Other values mean the parser should still walk the statement

fn module_declaration( &self, _parser: &mut JavascriptParser<'_>, _decl: &ModuleDecl, ) -> Option<bool>

fn block_pre_module_declaration( &self, _parser: &mut JavascriptParser<'_>, _decl: &ModuleDecl, ) -> Option<bool>

Return: None means continue this ModuleDecl Others means skip this.

This is similar hooks.block_pre_statement in webpack

fn pre_declarator( &self, _parser: &mut JavascriptParser<'_>, _declarator: &VarDeclarator, _declaration: VariableDeclaration<'_>, ) -> Option<bool>

fn evaluate<'a>( &self, _parser: &mut JavascriptParser<'_>, _expr: &'a Expr, ) -> Option<BasicEvaluatedExpression<'a>>

fn evaluate_typeof<'a>( &self, _parser: &mut JavascriptParser<'_>, _expr: &'a UnaryExpr, _for_name: &str, ) -> Option<BasicEvaluatedExpression<'a>>

fn evaluate_identifier( &self, _parser: &mut JavascriptParser<'_>, _for_name: &str, _start: u32, _end: u32, ) -> Option<BasicEvaluatedExpression<'static>>

fn evaluate_call_expression<'a>( &self, _parser: &mut JavascriptParser<'_>, _name: &str, _expr: &'a CallExpr, ) -> Option<BasicEvaluatedExpression<'a>>

Evaluate CallExpression when callee is an Identifier (e.g. String(), Number()). Mirrors webpack’s hooks.evaluateCallExpression.

fn evaluate_call_expression_member<'a>( &self, _parser: &mut JavascriptParser<'_>, _property: &str, _expr: &'a CallExpr, _param: BasicEvaluatedExpression<'a>, ) -> Option<BasicEvaluatedExpression<'a>>

fn can_collect_destructuring_assignment_properties( &self, _parser: &mut JavascriptParser<'_>, _expr: &Expr, ) -> Option<bool>

fn pattern( &self, _parser: &mut JavascriptParser<'_>, _ident: &Ident, _for_name: &str, ) -> Option<bool>

fn call( &self, _parser: &mut JavascriptParser<'_>, _expr: &CallExpr, _for_name: &str, ) -> Option<bool>

fn call_member_chain( &self, _parser: &mut JavascriptParser<'_>, _expr: &CallExpr, _for_name: &str, _members: &[Atom], _members_optionals: &[bool], _member_ranges: &[Span], ) -> Option<bool>

fn member( &self, _parser: &mut JavascriptParser<'_>, _expr: &MemberExpr, _for_name: &str, ) -> Option<bool>

fn member_chain( &self, _parser: &mut JavascriptParser<'_>, _expr: &MemberExpr, _for_name: &str, _members: &[Atom], _members_optionals: &[bool], _member_ranges: &[Span], ) -> Option<bool>

fn unhandled_expression_member_chain( &self, _parser: &mut JavascriptParser<'_>, _root_info: &ExportedVariableInfo, _expr: &MemberExpr, ) -> Option<bool>

fn member_chain_of_call_member_chain( &self, _parser: &mut JavascriptParser<'_>, _member_expr: &MemberExpr, _callee_members: &[Atom], _call_expr: &CallExpr, _members: &[Atom], _member_ranges: &[Span], _for_name: &str, ) -> Option<bool>

fn call_member_chain_of_call_member_chain( &self, _parser: &mut JavascriptParser<'_>, _call_expr: &CallExpr, _callee_members: &[Atom], _inner_call_expr: &CallExpr, _members: &[Atom], _member_ranges: &[Span], _for_name: &str, ) -> Option<bool>

fn typeof( &self, _parser: &mut JavascriptParser<'_>, _expr: &UnaryExpr, _for_name: &str, ) -> Option<bool>

fn expression_logical_operator( &self, _parser: &mut JavascriptParser<'_>, _expr: &BinExpr, ) -> Option<bool>

Return:

• None means should walk left and right;
• Some(true) means should walk right;
• Some(false) means nothing need to do.

fn binary_expression( &self, _parser: &mut JavascriptParser<'_>, _expr: &BinExpr, ) -> Option<bool>

Return:

• None means should walk left and right;

fn statement_if( &self, _parser: &mut JavascriptParser<'_>, _expr: &IfStmt, ) -> Option<bool>

Return:

• None means need walk stmt.test, stmt.cons and stmt.alt;
• Some(true) means only need walk stmt.cons;
• Some(false) means only need walk stmt.alt;

fn class_extends_expression( &self, _parser: &mut JavascriptParser<'_>, _super_class: &Expr, _class_decl_or_expr: ClassDeclOrExpr<'_>, ) -> Option<bool>

fn class_body_element( &self, _parser: &mut JavascriptParser<'_>, _element: &ClassMember, _class_decl_or_expr: ClassDeclOrExpr<'_>, ) -> Option<bool>

fn class_body_value( &self, _parser: &mut JavascriptParser<'_>, _element: &ClassMember, _expr_span: Span, _class_decl_or_expr: ClassDeclOrExpr<'_>, ) -> Option<bool>

fn declarator( &self, _parser: &mut JavascriptParser<'_>, _expr: &VarDeclarator, _stmt: VariableDeclaration<'_>, ) -> Option<bool>

fn new_expression( &self, _parser: &mut JavascriptParser<'_>, _expr: &NewExpr, _for_name: &str, ) -> Option<bool>

fn identifier( &self, _parser: &mut JavascriptParser<'_>, _ident: &Ident, _for_name: &str, ) -> Option<bool>

fn this( &self, _parser: &mut JavascriptParser<'_>, _expr: &ThisExpr, _for_name: &str, ) -> Option<bool>

fn assign( &self, _parser: &mut JavascriptParser<'_>, _expr: &AssignExpr, _for_name: &str, ) -> Option<bool>

fn assign_member_chain( &self, _parser: &mut JavascriptParser<'_>, _expr: &AssignExpr, _members: &[Atom], _for_name: &str, ) -> Option<bool>

fn import_call( &self, _parser: &mut JavascriptParser<'_>, _expr: &CallExpr, _import_then: Option<&CallExpr>, _members: Option<(&[Atom], bool)>, ) -> Option<bool>

fn meta_property( &self, _parser: &mut JavascriptParser<'_>, _root_name: &Atom, _span: Span, ) -> Option<bool>

fn import( &self, _parser: &mut JavascriptParser<'_>, _statement: &ImportDecl, _source: &str, ) -> Option<bool>

fn import_specifier( &self, _parser: &mut JavascriptParser<'_>, _statement: &ImportDecl, _source: &Atom, _export_name: Option<&Atom>, _identifier_name: &Atom, ) -> Option<bool>

fn export_import( &self, _parser: &mut JavascriptParser<'_>, _statement: ExportImport<'_>, _source: &Atom, ) -> Option<bool>

fn export( &self, _parser: &mut JavascriptParser<'_>, _statement: ExportLocal<'_>, ) -> Option<bool>

fn export_import_specifier( &self, _parser: &mut JavascriptParser<'_>, _statement: ExportImport<'_>, _source: &Atom, _local_id: Option<&Atom>, _export_name: Option<&Atom>, _export_name_span: Option<Span>, ) -> Option<bool>

fn export_specifier( &self, _parser: &mut JavascriptParser<'_>, _statement: ExportLocal<'_>, _local_id: &Atom, _export_name: &Atom, _export_name_span: Span, ) -> Option<bool>

fn export_expression( &self, _parser: &mut JavascriptParser<'_>, _statement: ExportDefaultDeclaration<'_>, _expr: ExportDefaultExpression<'_>, ) -> Option<bool>

fn optional_chaining( &self, _parser: &mut JavascriptParser<'_>, _expr: &OptChainExpr, ) -> Option<bool>

fn expression_conditional_operation( &self, _parser: &mut JavascriptParser<'_>, _expr: &CondExpr, ) -> Option<bool>

fn finish(&self, _parser: &mut JavascriptParser<'_>) -> Option<bool>

fn is_pure( &self, _parser: &mut JavascriptParser<'_>, _expr: &Expr, ) -> Option<bool>

fn import_meta_property_in_destructuring( &self, _parser: &mut JavascriptParser<'_>, _property: &DestructuringAssignmentProperty, ) -> Option<String>

This method is used to interop with other plugins. It will be called in ImportMetaPlugin when processing destructuring of import.meta

Implementors

impl JavascriptParserPlugin for ImportMetaHotReplacementParserPlugin

impl JavascriptParserPlugin for ModuleHotReplacementParserPlugin

impl JavascriptParserPlugin for NodeStuffPlugin

impl JavascriptParserPlugin for SideEffectsParserPlugin