fix(typescript): Skip the body of ArrowExpr in type usage analysis (#10187)

Author: CPunisher

.changeset/unlucky-olives-whisper.md

@@ -0,0 +1,6 @@
+---
+swc_typescript: patch
+swc_core: patch
+---
+
+fix(typescript): Skip the body of ArrowExpr in type usage analysis 

crates/swc_typescript/src/fast_dts/visitors/type_usage.rs

@@ -6,9 +6,9 @@ use petgraph::{
 use rustc_hash::{FxHashMap, FxHashSet};
 use swc_common::{BytePos, Spanned, SyntaxContext};
 use swc_ecma_ast::{
-    Accessibility, Class, ClassMember, Decl, ExportDecl, ExportDefaultDecl, ExportDefaultExpr,
-    Function, Id, Ident, ModuleExportName, ModuleItem, NamedExport, TsEntityName,
-    TsExportAssignment, TsExprWithTypeArgs, TsPropertySignature, TsTypeElement,
+    Accessibility, ArrowExpr, Class, ClassMember, Decl, ExportDecl, ExportDefaultDecl,
+    ExportDefaultExpr, Function, Id, Ident, ModuleExportName, ModuleItem, NamedExport,
+    TsEntityName, TsExportAssignment, TsExprWithTypeArgs, TsPropertySignature, TsTypeElement,
 };
 use swc_ecma_visit::{Visit, VisitWith};
 
@@ -230,6 +230,13 @@ impl Visit for TypeUsageAnalyzer<'_> {
         });
     }
 
+    fn visit_arrow_expr(&mut self, node: &ArrowExpr) {
+        // Skip body
+        node.params.visit_with(self);
+        node.type_params.visit_with(self);
+        node.return_type.visit_with(self);
+    }
+
     fn visit_function(&mut self, node: &Function) {
         // Skip body
         node.params.visit_with(self);

crates/swc_typescript/tests/fixture/issues/10171.snap

@@ -0,0 +1,8 @@
+```==================== .D.TS ====================
+
+export declare const Externals: {
+    Pinkie: string;
+};
+export declare const magical: () => string;
+
+

crates/swc_typescript/tests/fixture/issues/10171.ts

@@ -0,0 +1,16 @@
+export const Externals = {
+    Pinkie: "Pinkie Pie",
+};
+
+const Ponies = {
+    name: Externals.Pinkie,
+};
+
+type Pony = keyof typeof Ponies;
+
+export const magical = (): string => {
+    const pinkie = (): Pony => "name";
+
+    console.log(Ponies.name);
+    return pinkie();
+};