From aea69bb9651cb70bc105fae5a121b6b461c5542e Mon Sep 17 00:00:00 2001
From: Marcin Romaszewicz <marcinr@gmail.com>
Date: Sun, 12 Jul 2026 11:03:32 -0700
Subject: [PATCH] Add regression test for enum values containing backslashes
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Closes: #2180

The reported miscompilation — a string enum value like N\A emitted
verbatim into a double-quoted Go literal — was already fixed by #2433,
which routes string enum constants through strconv.Quote. That change
shipped without an end-to-end test for this scenario, so pin it with a
test generating from the issue's schema and asserting the escaped
constant and formattable output.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 pkg/codegen/codegen_test.go | 41 +++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/pkg/codegen/codegen_test.go b/pkg/codegen/codegen_test.go
index e468e03d8..8b5abd5a5 100644
--- a/pkg/codegen/codegen_test.go
+++ b/pkg/codegen/codegen_test.go
@@ -581,6 +581,47 @@ paths:
 	assert.Contains(t, code, `ctx = context.WithValue(ctx, BearerAuthScopes, []string{"read"})`)
 }
 
+// TestEnumValueEscaping verifies that a string enum value containing a
+// backslash is emitted as a valid, properly escaped Go string literal
+// (the constants go through strconv.Quote).
+// Please see https://github.com/oapi-codegen/oapi-codegen/issues/2180
+func TestEnumValueEscaping(t *testing.T) {
+	const spec = `
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Enum escaping
+paths: {}
+components:
+  schemas:
+    AutoAccident:
+      type: object
+      properties:
+        significant_injury:
+          type: string
+          enum: ["YES", "NO", "N\\A"]
+`
+	loader := openapi3.NewLoader()
+	swagger, err := loader.LoadFromData([]byte(spec))
+	require.NoError(t, err)
+
+	opts := Configuration{
+		PackageName:   "api",
+		Generate:      GenerateOptions{Models: true},
+		OutputOptions: OutputOptions{SkipPrune: true},
+	}
+
+	code, err := Generate(swagger, opts)
+	require.NoError(t, err)
+
+	// The spec-level value is the three characters N, \, A; the generated
+	// constant must escape the backslash.
+	assert.Contains(t, code, `= "N\\A"`)
+
+	_, err = format.Source([]byte(code))
+	require.NoError(t, err)
+}
+
 const securityScopesSharedSpec = `
 openapi: "3.0.0"
 info: