fix(semantic): bind SymbolId to function name in if (foo) function id() {} (#5673)

crates/oxc_semantic/src/binder.rs

@@ -10,7 +10,11 @@ use oxc_ast::{
 };
 use oxc_span::{GetSpan, SourceType};
 
-use crate::{scope::ScopeFlags, symbol::SymbolFlags, SemanticBuilder};
+use crate::{
+    scope::{ScopeFlags, ScopeId},
+    symbol::SymbolFlags,
+    SemanticBuilder,
+};
 
 pub(crate) trait Binder<'a> {
     #[allow(unused_variables)]
@@ -132,19 +136,42 @@ fn function_as_var(flags: ScopeFlags, source_type: SourceType) -> bool {
     flags.is_function() || (source_type.is_script() && flags.is_top())
 }
 
+/// Check for Annex B `if (foo) function a() {} else function b() {}`
+fn is_function_part_of_if_statement(function: &Function, builder: &SemanticBuilder) -> bool {
+    if builder.current_scope_flags().is_strict_mode() {
+        return false;
+    }
+    let Some(AstKind::IfStatement(stmt)) = builder.nodes.parent_kind(builder.current_node_id)
+    else {
+        return false;
+    };
+    if let Statement::FunctionDeclaration(func) = &stmt.consequent {
+        if func.span == function.span {
+            return true;
+        }
+    }
+    if let Some(Statement::FunctionDeclaration(func)) = &stmt.alternate {
+        if func.span == function.span {
+            return true;
+        }
+    }
+    false
+}
+
 impl<'a> Binder<'a> for Function<'a> {
     fn bind(&self, builder: &mut SemanticBuilder) {
         let current_scope_id = builder.current_scope_id;
         let scope_flags = builder.current_scope_flags();
         if let Some(ident) = &self.id {
-            if !scope_flags.is_strict_mode()
-                && matches!(
-                    builder.nodes.parent_kind(builder.current_node_id),
-                    Some(AstKind::IfStatement(_))
-                )
-            {
-                // Do not declare in if single statements,
-                // if (false) function f() {} else function g() { }
+            if is_function_part_of_if_statement(self, builder) {
+                let symbol_id = builder.symbols.create_symbol(
+                    ident.span,
+                    ident.name.clone().into(),
+                    SymbolFlags::Function,
+                    ScopeId::new(u32::MAX - 1), // Not bound to any scope.
+                    builder.current_node_id,
+                );
+                ident.symbol_id.set(Some(symbol_id));
             } else if self.r#type == FunctionType::FunctionDeclaration {
                 // The visitor is already inside the function scope,
                 // retrieve the parent scope for the function id to bind to.

crates/oxc_semantic/src/post_transform_checker.rs

@@ -648,22 +648,6 @@ impl<'a, 'e> Visit<'a> for SemanticIdsCollector<'e> {
         walk::walk_declaration(self, it);
     }
 
-    fn visit_if_statement(&mut self, stmt: &IfStatement<'a>) {
-        // skip `if (function foo() {}) {}`
-        if !matches!(stmt.test, Expression::FunctionExpression(_)) {
-            self.visit_expression(&stmt.test);
-        }
-        // skip `if (true) function foo() {} else function bar() {}`
-        if !stmt.consequent.is_declaration() {
-            self.visit_statement(&stmt.consequent);
-        }
-        if let Some(alternate) = &stmt.alternate {
-            if !alternate.is_declaration() {
-                self.visit_statement(alternate);
-            }
-        }
-    }
-
     fn visit_ts_type(&mut self, _it: &TSType<'a>) {
         /* noop */
     }

tasks/coverage/semantic_babel.snap

@@ -2,11 +2,14 @@ commit: 3bcfee23
 
 semantic_babel Summary:
 AST Parsed     : 2101/2101 (100.00%)
-Positive Passed: 1737/2101 (82.67%)
+Positive Passed: 1739/2101 (82.77%)
 tasks/coverage/babel/packages/babel-parser/test/fixtures/annex-b/enabled/3.3-function-in-if-body/input.js
-semantic error: Scope children mismatch:
-after transform: ScopeId(0): [ScopeId(1), ScopeId(2)]
-rebuilt        : ScopeId(0): [ScopeId(1), ScopeId(2)]
+semantic error: Symbol scope ID mismatch:
+after transform: SymbolId(0): ScopeId(4294967294)
+rebuilt        : SymbolId(0): ScopeId(4294967294)
+Symbol scope ID mismatch:
+after transform: SymbolId(1): ScopeId(4294967294)
+rebuilt        : SymbolId(1): ScopeId(4294967294)
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/comments/interpreter-directive/interpreter-directive-import/input.js
 semantic error: Bindings mismatch:
@@ -23,14 +26,9 @@ semantic error: Unexpected new.target expression
 Unexpected new.target expression
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/core/scope/dupl-bind-catch-hang-func/input.js
-semantic error: Scope children mismatch:
-after transform: ScopeId(3): [ScopeId(4)]
-rebuilt        : ScopeId(3): [ScopeId(4)]
-
-tasks/coverage/babel/packages/babel-parser/test/fixtures/core/uncategorised/230/input.js
-semantic error: Binding symbols mismatch:
-after transform: ScopeId(0): [SymbolId(0)]
-rebuilt        : ScopeId(0): [SymbolId(0)]
+semantic error: Symbol scope ID mismatch:
+after transform: SymbolId(1): ScopeId(4294967294)
+rebuilt        : SymbolId(1): ScopeId(4294967294)
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/core/uncategorised/327/input.js
 semantic error: A 'return' statement can only be used within a function body.
@@ -138,15 +136,10 @@ semantic error: Bindings mismatch:
 after transform: ScopeId(0): ["nil"]
 rebuilt        : ScopeId(0): []
 
-tasks/coverage/babel/packages/babel-parser/test/fixtures/esprima/statement-if/migrated_0002/input.js
-semantic error: Binding symbols mismatch:
-after transform: ScopeId(0): [SymbolId(0)]
-rebuilt        : ScopeId(0): [SymbolId(0)]
-
 tasks/coverage/babel/packages/babel-parser/test/fixtures/esprima/statement-if/migrated_0003/input.js
-semantic error: Scope children mismatch:
-after transform: ScopeId(0): [ScopeId(1)]
-rebuilt        : ScopeId(0): [ScopeId(1)]
+semantic error: Symbol scope ID mismatch:
+after transform: SymbolId(0): ScopeId(4294967294)
+rebuilt        : SymbolId(0): ScopeId(4294967294)
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/arrow-function/arrow-function-with-newline/input.ts
 semantic error: Unresolved references mismatch: