From dbcdd5f3c9b2ba7859d4c3b0af2425b675e85e82 Mon Sep 17 00:00:00 2001
From: Sergio Salvatore <sergio@vimeo.com>
Date: Thu, 29 Aug 2024 14:25:17 -0400
Subject: [PATCH] TextUnmarshaler is Excluded from Mangling

We shouldn't ever mangle types that implement TextUnmarshaler.
---
 transform/transformer.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/transform/transformer.go b/transform/transformer.go
index 3e98da6..cb345ae 100644
--- a/transform/transformer.go
+++ b/transform/transformer.go
@@ -128,12 +128,20 @@ func (t *Transformer) maybeRecursivelyMangle(mangler Mangler, state *transformMa
 		if !mangler.ShouldRecurse(field) {
 			continue
 		}
+
 		ft := field.Type
+
+		// also don't recurse into TextUnarshaler types
+		if ft.Implements(textMReflectType) || reflect.PointerTo(ft).Implements(textMReflectType) {
+			continue
+		}
+
 		// strip any outer pointerification, slice or array
 		switch ft.Kind() {
 		case reflect.Ptr, reflect.Array, reflect.Slice:
 			ft = ft.Elem()
 		}
+
 		fieldTransformer := Transformer{
 			manglers: []Mangler{mangler},
 			mState:   nil,