From d3eb1c3318a1ff0263d8ea772d3a323f14fd5d20 Mon Sep 17 00:00:00 2001
From: Don Isaac <donald.isaac@gmail.com>
Date: Tue, 2 Apr 2024 22:42:11 -0400
Subject: [PATCH] fix(semantic): flag function expressions with
 `SymbolFlags::Function` (#2891)

# What This PR Does

Consider the following code snippet

```js
const x = function y () {{
```

`y` will now be flagged with `SymbolFlags::Function`. This follow's
tsc's behavior.

- [Example in OXC
Playground](https://oxc-project.github.io/oxc/playground/?code=3YCAAICagICAgICAgICxG0qZRraXZOpcCHVsSRwDq2kRR0HprsTfRRT5WMw%2Ff2epoIA%3D)
- [Example in TypeScript AST
Viewer](https://ts-ast-viewer.com/#code/MYewdgzgLgBAHjAvDAZgVzMKBLcMCeAFAJQwDeAvgFBA)
---
 crates/oxc_semantic/src/binder.rs    |  2 +-
 crates/oxc_semantic/tests/symbols.rs | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/crates/oxc_semantic/src/binder.rs b/crates/oxc_semantic/src/binder.rs
index 9bd0010b6..17b972466 100644
--- a/crates/oxc_semantic/src/binder.rs
+++ b/crates/oxc_semantic/src/binder.rs
@@ -146,7 +146,7 @@ impl<'a> Binder for Function<'a> {
                 let symbol_id = builder.declare_symbol(
                     ident.span,
                     &ident.name,
-                    SymbolFlags::empty(),
+                    SymbolFlags::Function,
                     SymbolFlags::empty(),
                 );
                 ident.symbol_id.set(Some(symbol_id));
diff --git a/crates/oxc_semantic/tests/symbols.rs b/crates/oxc_semantic/tests/symbols.rs
index d2054d2e7..1dbaa81d0 100644
--- a/crates/oxc_semantic/tests/symbols.rs
+++ b/crates/oxc_semantic/tests/symbols.rs
@@ -26,6 +26,18 @@ fn test_function_simple() {
         .test();
 }
 
+#[test]
+fn test_function_expressions() {
+    SemanticTester::js("const x = function y() {}")
+        .has_some_symbol("y")
+        .contains_flags(SymbolFlags::Function)
+        .test();
+    SemanticTester::js("const x = () => {}")
+        .has_some_symbol("x")
+        .contains_flags(SymbolFlags::BlockScopedVariable | SymbolFlags::ConstVariable)
+        .test();
+}
+
 #[test]
 fn test_var_simple() {
     SemanticTester::js("let x; { let y; }")