refactor(transformer): move and simplify TS enum transform entry point (#3760)

Move logic for TS enum transform into `enum.rs`. Also simplify the logic, using `Statement` enum variants directly.

Author: overlookmotel

crates/oxc_transformer/src/typescript/enum.rs

@@ -20,6 +20,26 @@ impl<'a> TypeScriptEnum<'a> {
         Self { ctx, enums: FxHashMap::default() }
     }
 
+    pub fn transform_statement(&mut self, stmt: &mut Statement<'a>, ctx: &TraverseCtx<'a>) {
+        let new_stmt = match stmt {
+            Statement::TSEnumDeclaration(ts_enum_decl) => {
+                self.transform_ts_enum(ts_enum_decl, false, ctx)
+            }
+            Statement::ExportNamedDeclaration(decl) => {
+                if let Some(Declaration::TSEnumDeclaration(ts_enum_decl)) = &decl.declaration {
+                    self.transform_ts_enum(ts_enum_decl, true, ctx)
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        };
+
+        if let Some(new_stmt) = new_stmt {
+            *stmt = new_stmt;
+        }
+    }
+
     /// ```TypeScript
     /// enum Foo {
     ///   X = 1,

crates/oxc_transformer/src/typescript/mod.rs

@@ -152,33 +152,7 @@ impl<'a> TypeScript<'a> {
     }
 
     pub fn transform_statement(&mut self, stmt: &mut Statement<'a>, ctx: &TraverseCtx<'a>) {
-        let new_stmt = match stmt {
-            match_declaration!(Statement) => {
-                if let Declaration::TSEnumDeclaration(ts_enum_decl) = &stmt.to_declaration() {
-                    self.r#enum.transform_ts_enum(ts_enum_decl, false, ctx)
-                } else {
-                    None
-                }
-            }
-            match_module_declaration!(Statement) => {
-                if let ModuleDeclaration::ExportNamedDeclaration(decl) =
-                    stmt.to_module_declaration_mut()
-                {
-                    if let Some(Declaration::TSEnumDeclaration(ts_enum_decl)) = &decl.declaration {
-                        self.r#enum.transform_ts_enum(ts_enum_decl, true, ctx)
-                    } else {
-                        None
-                    }
-                } else {
-                    None
-                }
-            }
-            _ => None,
-        };
-
-        if let Some(new_stmt) = new_stmt {
-            *stmt = new_stmt;
-        }
+        self.r#enum.transform_statement(stmt, ctx);
     }
 
     pub fn transform_if_statement(&mut self, stmt: &mut IfStatement<'a>) {