#946 not modifying request header key when matching

Author: tommysitu

core/matching/header_matcher.go

@@ -21,13 +21,13 @@ func HeaderMatching(requestMatcher models.RequestMatcher, toMatch map[string][]s
 
 	for matcherHeaderKey, matcherHeaderValue := range requestMatcherHeadersWithMatchers {
 		// Make everything lowercase, as headers are case insensitive
-		for requestHeaderKey, requestHeaderValues := range toMatch {
-			delete(toMatch, requestHeaderKey)
-			toMatch[strings.ToLower(requestHeaderKey)] = requestHeaderValues
+		toMatchWithLowerCaseKeys := make(map[string][]string)
+		for key, value := range toMatch {
+			toMatchWithLowerCaseKeys[strings.ToLower(key)] = value
 		}
 		matcherHeaderValueMatched := false
 
-		toMatchHeaderValues, found := toMatch[strings.ToLower(matcherHeaderKey)]
+		toMatchHeaderValues, found := toMatchWithLowerCaseKeys[strings.ToLower(matcherHeaderKey)]
 		if !found {
 			matched = false
 			continue

core/matching/header_matcher_test.go

@@ -177,3 +177,29 @@ func Test_HeaderMatching(t *testing.T) {
 	}
 
 }
+
+
+func Test_HeaderMatching_NotModifyingOriginalRequestHeaders(t *testing.T) {
+	RegisterTestingT(t)
+
+	requestHeaders := map[string][]string{
+		"Header1": {"val1"},
+	}
+	result := matching.HeaderMatching(models.RequestMatcher{
+		Headers: map[string][]models.RequestFieldMatchers{
+			"HEADER1": {
+				{
+					Matcher: matchers.Exact,
+					Value:   "val1",
+				},
+			},
+		},
+	},
+		requestHeaders)
+
+	Expect(result.Matched).To(BeTrue())
+	Expect(requestHeaders).To(Equal(map[string][]string{
+		"Header1": {"val1"},
+	}))
+
+}