fix(semantic): add scope tracking for with statements

[Boshen]

Fixes #8365

Summary

The with statement was not creating a scope in the semantic analysis, causing is_global_reference to incorrectly return true for references inside with blocks. This could lead to incorrect minification.

Problem

According to the ECMAScript specification, with statements should create an Object Environment Record that extends the lexical environment. Without proper scope tracking:

• is_global_reference() incorrectly returns true for identifiers inside with blocks
• This can cause minification to incorrectly treat local references as global
• The scope tree doesn't accurately represent the program structure

Solution

Changes Made

1. AST Definition (crates/oxc_ast/src/ast/js.rs):

   • Added #[scope] attribute to WithStatement struct
   • Added scope_id: Cell<Option<ScopeId>> field

2. Semantic Builder (crates/oxc_semantic/src/builder.rs):

   • Modified visit_with_statement to call enter_scope() before visiting the body
   • Added leave_scope() call after visiting the body
   • Uses ScopeFlags::empty() similar to block statements

3. Test Coverage (crates/oxc_semantic/tests/integration/scopes.rs):

   • Added test_with_statement to verify scope creation
   • Tests both simple expressions and block statement bodies
   • Verifies proper scope tree structure

Example

const foo = {
  Object: class {
    constructor() { console.log('Constructor') }
  }
}
with (foo) {
  console.log(new Object()) // should print "Constructor"
}

Before this fix, Object inside the with block would be incorrectly identified as a global reference, potentially causing minification errors.

Implementation Notes

While this implementation doesn't fully model the complex object environment semantics (where property lookups can dynamically affect identifier resolution at runtime), it ensures:

• References inside with blocks are no longer incorrectly marked as global
• The scope tree properly represents the lexical structure
• Provides a foundation for future improvements to object environment handling

Testing

All existing tests pass, plus the new test verifies:

• with statements create scopes
• Scopes are properly nested in the scope tree
• Works correctly with both simple and block statement bodies

[Copilot]

Pull Request Overview

This PR fixes a bug in the semantic analysis where with statements were not properly creating scopes, causing incorrect global reference detection and potential minification issues. The fix ensures that with statements create proper lexical scopes according to the ECMAScript specification.

Key changes:

• Added scope tracking to WithStatement in the AST definition
• Modified the semantic builder to create and manage scopes for with statements
• Added comprehensive test coverage to verify proper scope creation and tree structure

Reviewed Changes

Copilot reviewed 3 out of 13 changed files in this pull request and generated no comments.

File	Description
crates/oxc_ast/src/ast/js.rs	Added #[scope] attribute and scope_id field to WithStatement struct
crates/oxc_semantic/src/builder.rs	Modified visit_with_statement to enter/leave scopes around the body
crates/oxc_semantic/tests/integration/scopes.rs	Added comprehensive test coverage for with statement scope creation

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[graphite-app]

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[codspeed-hq]

CodSpeed Performance Report

Merging #14652 will not alter performance

_{Comparing fix/with-statement-scope (be94bfd) with main (c69201c)}

Summary

✅ 37 untouched

[overlookmotel]

I think the scope should not cover object - scope should be entered just before body. This is similar to SwitchStatement.

[Boshen]

Merge activity

• Oct 16, 10:01 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Oct 16, 10:01 AM UTC: Boshen added this pull request to the Graphite merge queue.
• Oct 16, 10:07 AM UTC: Merged by the Graphite merge queue.