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fix(es/minifier): avoid moved binding collisions #11981

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121 changes: 121 additions & 0 deletions crates/swc_ecma_minifier/tests/exec.rs
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -292,6 +292,45 @@ fn run_default_exec_test(input_src: &str) {
run_exec_test(input_src, config, false);
}

fn run_compress_and_mangle_exec_test(input_src: &str, config: &str) {
let expected_output = stdout_of(input_src).unwrap();

testing::run_test2(false, |cm, handler| {
let _tracing = span!(Level::ERROR, "compress-and-mangle").entered();

let output = run(
cm.clone(),
&handler,
input_src,
Some(config),
Some(MangleOptions {
top_level: Some(true),
..Default::default()
}),
);

let output = output.expect("Parsing in base test should not fail");
let output = print(cm, &[&output], true, false);

eprintln!(
"---- {} -----\n{}",
Color::Green.paint("Optimized code"),
output
);

let actual_output = stdout_of(&output).expect("failed to execute the optimized code");
assert_ne!(actual_output, "");

assert_eq!(
DebugUsingDisplay(&actual_output),
DebugUsingDisplay(&expected_output)
);

Ok(())
})
.unwrap();
}

#[test]
fn concat_tpl_keeps_delimiter_after_interpolation() {
run_default_exec_test(
Expand Down Expand Up @@ -12363,6 +12402,88 @@ console.log(out.poisoned);
run_default_exec_test(src);
}

#[test]
fn issue_11977_iife_param_extraction_does_not_collide_with_var() {
let src = r#"
var d = class {};
var __turbopack_context__ = {
z: function(value) {
return value;
}
};
var ErrorType = 1;
var i = {};
var serverOnlyRequire;
var Subscription = function() {
function Subscription1(listeners, listener) {}
Subscription1.prototype.add = function(subscription) {
if (this.unsubscribed) {}
};
}();
try {
serverOnlyRequire = eval('require');
} catch (err) {}
var __require = /* @__PURE__ */ ((x)=>("TURBOPACK compile-time truthy", 1) ? __turbopack_context__.z : "TURBOPACK unreachable")(function(x) {
})(ErrorType || {});
var isRequestError = (error)=>{
let u = i.getKey ?? ((p, s)=>`x`), f = async ()=>{
try {} catch (s) {}
};
};
var x = class extends d {};
console.log(typeof x, x === x);
"#;
let config = r#"{
"defaults": true,
"toplevel": true
}"#;

run_compress_and_mangle_exec_test(src, config);
}

#[test]
fn issue_11977_iife_param_extraction_does_not_collide_in_function() {
let src = r#"
var g = {};
var d = class {};
var __turbopack_context__ = {
z: function(value) {
return value;
}
};
var ErrorType = 1;
var i = {};
var serverOnlyRequire;
g.foo = function() {
var Subscription = function() {
function Subscription1(listeners, listener) {}
Subscription1.prototype.add = function(subscription) {
if (this.unsubscribed) {}
};
}();
try {
serverOnlyRequire = eval('require');
} catch (err) {}
var __require = /* @__PURE__ */ ((x)=>("TURBOPACK compile-time truthy", 1) ? __turbopack_context__.z : "TURBOPACK unreachable")(function(x) {
})(ErrorType || {});
var isRequestError = (error)=>{
let u = i.getKey ?? ((p, s)=>`x`), f = async ()=>{
try {} catch (s) {}
};
};
var x = class extends d {};
console.log(typeof x, x === x);
};
g.foo();
"#;
let config = r#"{
"defaults": true,
"toplevel": true
}"#;

run_compress_and_mangle_exec_test(src, config);
}

#[test]
fn issue_11294_eval_mangle_no_collision() {
// Regression test for #11294.
Expand Down
36 changes: 18 additions & 18 deletions crates/swc_ecma_transforms_base/src/rename/analyer_and_collector.rs
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -87,7 +87,7 @@ impl Visit for AnalyzerAndCollector {
let old_decl_collector_is_pat_decl = self.decl_collector.is_pat_decl;
self.decl_collector.is_pat_decl = true;

let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.ctxt);

@chatgpt-codex-connector chatgpt-codex-connector Bot Jul 3, 2026

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P2 Badge Preserve arrow parameters visible to eval

For arrows with direct eval, e.g. const f = (longName) => eval("longName"), the resolver creates a child function scope for the parameters but never marks ArrowExpr::ctxt; only a block body gets marked, and expression-bodied arrows have no marked body to use. Passing this empty context makes eval preservation compare the parameter context against SyntaxContext::empty(), so mangle can rename longName while eval still looks up the original string.

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let old_analyzer_is_pat_decl = self.analyzer.is_pat_decl;
self.analyzer.is_pat_decl = true;

Expand Down Expand Up @@ -133,7 +133,7 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_block_stmt(&mut self, node: &BlockStmt) {
let old_analyzer = self.analyzer.enter_block_scope();
let old_analyzer = self.analyzer.enter_block_scope(Some(node.ctxt));

node.visit_children_with(self);

Expand All @@ -147,7 +147,7 @@ impl Visit for AnalyzerAndCollector {
fn visit_catch_clause(&mut self, node: &CatchClause) {
let old_decl_collector_is_pat_decl = self.decl_collector.is_pat_decl;

let old_analyzer = self.analyzer.enter_block_scope();
let old_analyzer = self.analyzer.enter_block_scope(Some(node.body.ctxt));
let old_analyzer_is_pat_decl = self.analyzer.is_pat_decl;
let old_analyzer_in_catch_params = self.analyzer.in_catch_params;

Expand Down Expand Up @@ -179,7 +179,7 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_class_expr(&mut self, node: &ClassExpr) {
let old_analyzer = self.analyzer.enter_block_scope();
let old_analyzer = self.analyzer.enter_block_scope(Some(node.class.ctxt));

@chatgpt-codex-connector chatgpt-codex-connector Bot Jul 3, 2026

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P2 Badge Preserve named class expressions seen by eval

With direct eval inside a named class expression, e.g. const C = class Foo { static m() { return eval("Foo") } }, this uses Class::ctxt as the source-scope context, but the resolver leaves Class::ctxt empty and marks the class-expression name in the child scope in visit_mut_class_expr. That makes id.1 == ctxt false for Foo, so the name is queued for mangling even though eval still resolves the string "Foo", regressing the eval-preservation behavior this code is trying to maintain.

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self.analyzer.handle_class_expr(node);

Expand All @@ -193,7 +193,7 @@ impl Visit for AnalyzerAndCollector {
fn visit_class_method(&mut self, node: &ClassMethod) {
node.key.visit_with(self);

let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.function.ctxt);

node.function.decorators.visit_with(self);
node.function.params.visit_with(self);
Expand All @@ -205,7 +205,7 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_constructor(&mut self, node: &Constructor) {
let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.ctxt);

@chatgpt-codex-connector chatgpt-codex-connector Bot Jul 3, 2026

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P2 Badge Use a marked constructor context for eval preservation

For class constructors with direct eval, such as class C { constructor(longName) { eval("longName") } }, Constructor::ctxt is never populated by the resolver; visit_mut_constructor creates a child function scope, marks parameters with that child mark, and only marks body.ctxt. Passing the empty node.ctxt here means constructor parameters and locals no longer match scope_ctxt, so they can be mangled while eval still looks up their original names.

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node.key.visit_with(self);
node.params.visit_with(self);
if let Some(body) = &node.body {
Expand All @@ -221,7 +221,7 @@ impl Visit for AnalyzerAndCollector {
self.analyzer.handle_class_expr(c);
self.decl_collector.handle_class_expr(c);

let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(c.class.ctxt);
c.visit_children_with(self);
self.analyzer.exit_scope(old_analyzer);
}
Expand Down Expand Up @@ -293,7 +293,7 @@ impl Visit for AnalyzerAndCollector {

node.ident.visit_with(self);

let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.function.ctxt);

if !need_skip_analyzer_record && has_rest {
// self.analyer is different from above because we are in a function scope
Expand All @@ -312,9 +312,9 @@ impl Visit for AnalyzerAndCollector {

fn visit_fn_expr(&mut self, node: &FnExpr) {
if let Some(id) = &node.ident {
let old_analyzer0 = self.analyzer.enter_fn_scope();
let old_analyzer0 = self.analyzer.enter_fn_scope(id.ctxt);
self.analyzer.add_decl(id.to_id(), true);
let old_analyzer1 = self.analyzer.enter_fn_scope();
let old_analyzer1 = self.analyzer.enter_fn_scope(node.function.ctxt);
// https://github.com/swc-project/swc/issues/6819
//
// We need to check for assign pattern because safari has a bug.
Expand Down Expand Up @@ -348,10 +348,10 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_for_in_stmt(&mut self, node: &ForInStmt) {
let old_analyzer0 = self.analyzer.enter_block_scope();
let old_analyzer0 = self.analyzer.enter_block_scope(None);
node.left.visit_with(self);
node.right.visit_with(self);
let old_analyzer1 = self.analyzer.enter_block_scope();
let old_analyzer1 = self.analyzer.enter_block_scope(None);
match node.body.as_ref() {
Stmt::Block(n) => n.visit_children_with(self),
_ => node.body.visit_with(self),
Expand All @@ -361,10 +361,10 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_for_of_stmt(&mut self, node: &ForOfStmt) {
let old_analyzer0 = self.analyzer.enter_block_scope();
let old_analyzer0 = self.analyzer.enter_block_scope(None);
node.left.visit_with(self);
node.right.visit_with(self);
let old_analyzer1 = self.analyzer.enter_block_scope();
let old_analyzer1 = self.analyzer.enter_block_scope(None);
match node.body.as_ref() {
Stmt::Block(n) => n.visit_children_with(self),
_ => node.body.visit_with(self),
Expand All @@ -374,11 +374,11 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_for_stmt(&mut self, node: &ForStmt) {
let old_analyzer0 = self.analyzer.enter_block_scope();
let old_analyzer0 = self.analyzer.enter_block_scope(None);
node.init.visit_with(self);
node.test.visit_with(self);
node.update.visit_with(self);
let old_analyzer1 = self.analyzer.enter_block_scope();
let old_analyzer1 = self.analyzer.enter_block_scope(None);
match node.body.as_ref() {
Stmt::Block(n) => n.visit_children_with(self),
_ => node.body.visit_with(self),
Expand All @@ -388,7 +388,7 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_function(&mut self, node: &Function) {
let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.ctxt);

node.decorators.visit_with(self);
node.params.visit_with(self);
Expand Down Expand Up @@ -447,7 +447,7 @@ impl Visit for AnalyzerAndCollector {
}

fn visit_static_block(&mut self, node: &StaticBlock) {
let old_analyzer = self.analyzer.enter_fn_scope();
let old_analyzer = self.analyzer.enter_fn_scope(node.body.ctxt);

node.body.visit_children_with(self);

Expand Down
26 changes: 18 additions & 8 deletions crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
use swc_common::Mark;
use swc_common::{Mark, SyntaxContext};
use swc_ecma_ast::*;

use self::scope::{Scope, ScopeKind};
Expand All @@ -18,6 +18,12 @@ pub(super) struct Analyzer {
pub(super) var_belong_to_fn_scope: bool,
pub(super) in_catch_params: bool,
pub(super) scope: Scope,
/// Context for declarations that belong directly to `scope`.
///
/// With direct `eval`, declarations created from the same source scope must
/// keep their printed names. Declarations moved from an inner scope are
/// still safe to rename, and the context lets us distinguish the two.
pub(super) scope_ctxt: Option<SyntaxContext>,
/// If we try add variables declared by `var` to the block scope,
/// variables will be added to `hoisted_vars` and merged to latest
/// function scope in the end.
Expand All @@ -43,6 +49,7 @@ impl Analyzer {
top_level_mark,
skip_first_fn_or_class_decl,
is_first_node: true,
scope_ctxt: Some(SyntaxContext::empty().apply_mark(top_level_mark)),
hoisted_vars: Vec::with_capacity(32),
mangle,
..Default::default()
Expand All @@ -53,12 +60,14 @@ impl Analyzer {
if belong_to_fn_scope {
match self.scope.kind {
ScopeKind::Fn => {
self.scope.add_decl(&id, self.has_eval, self.top_level_mark);
self.scope
.add_decl(&id, self.has_eval, self.top_level_mark, self.scope_ctxt);
}
ScopeKind::Block => self.hoisted_vars.push(id),
}
} else {
self.scope.add_decl(&id, self.has_eval, self.top_level_mark);
self.scope
.add_decl(&id, self.has_eval, self.top_level_mark, self.scope_ctxt);
}
}

Expand All @@ -85,10 +94,11 @@ impl Analyzer {
self.scope.reserve_usage(len);
}

fn enter_scope(&mut self, kind: ScopeKind) -> Self {
fn enter_scope(&mut self, kind: ScopeKind, scope_ctxt: Option<SyntaxContext>) -> Self {
let mut analyer = Analyzer {
has_eval: self.has_eval,
top_level_mark: self.top_level_mark,
scope_ctxt,
is_pat_decl: self.is_pat_decl,
var_belong_to_fn_scope: false,
in_catch_params: false,
Expand All @@ -105,12 +115,12 @@ impl Analyzer {
analyer // old analyzer
}

pub(super) fn enter_fn_scope(&mut self) -> Self {
self.enter_scope(ScopeKind::Fn)
pub(super) fn enter_fn_scope(&mut self, scope_ctxt: SyntaxContext) -> Self {
self.enter_scope(ScopeKind::Fn, Some(scope_ctxt))
}

pub(super) fn enter_block_scope(&mut self) -> Self {
self.enter_scope(ScopeKind::Block)
pub(super) fn enter_block_scope(&mut self, scope_ctxt: Option<SyntaxContext>) -> Self {
self.enter_scope(ScopeKind::Block, scope_ctxt)
}

pub(super) fn exit_scope(&mut self, mut v: Self) {
Expand Down
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