chore: add test for YAML unmarshalling (#396)

The new tests specifically test unmarshalling of line feed and carriage
return escape sequences in double qouted strings, as that was an issue
with goccy/go-yaml.

Refs #359

Co-authored-by: Felipe Zipitría <[email protected]>

test/yaml_test.go

@@ -0,0 +1,57 @@
+// Copyright 2024 OWASP CRS Project
+// SPDX-License-Identifier: Apache-2.0
+
+package test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"gopkg.in/yaml.v3"
+)
+
+type yamlTestSuite struct {
+	suite.Suite
+}
+
+func TestYamlTestSuite(t *testing.T) {
+	suite.Run(t, new(yamlTestSuite))
+}
+
+func (s *yamlTestSuite) TestUnmarshalling_LineFeed() {
+	s.testUnmarshalling(`\n`, "\n")
+}
+
+func (s *yamlTestSuite) TestUnmarshalling_CarriageReturn() {
+	s.testUnmarshalling(`\r`, "\r")
+
+}
+
+func (s *yamlTestSuite) testUnmarshalling(escapeSequence string, literal string) {
+	yamlTemplate := `---
+tests:
+  - test_id: 1234
+    stages:
+      - input:
+          headers:
+            "%s": "%s"
+`
+	keyTemplate := "Some%sHeader"
+	valueTemplate := "some%svalue"
+
+	key := fmt.Sprintf(keyTemplate, escapeSequence)
+	value := fmt.Sprintf(valueTemplate, escapeSequence)
+	expectedKey := fmt.Sprintf(keyTemplate, literal)
+	expectedValue := fmt.Sprintf(valueTemplate, literal)
+
+	yamlString := fmt.Sprintf(yamlTemplate, key, value)
+	test := &FTWTest{}
+
+	err := yaml.Unmarshal([]byte(yamlString), test)
+	s.Require().NoError(err)
+
+	headers := test.FTWTest.Tests[0].Stages[0].Input.Headers
+	s.Contains(headers, expectedKey)
+	s.Equal(expectedValue, headers[expectedKey])
+}