aws/request Fixes WithSetRequestHeaders key added to header map dir…

…ectly

Addresses an issue where the header keys being added were being added
directly to the header map, and did not have the canonical header casing
applied. This introduced bugs where instead of overwriting existing
header key, it added another map entry.

CHANGELOG_PENDING.md

@@ -1,4 +1,6 @@
 ### SDK Features
+* `aws/request`: Fixes bug in WithSetRequestHeaders where the header key was added to the header map directly
+  * Addresses an issue where the header keys being added were being added directly to the header map, and did not have the canonical header casing applied. This introduced bugs where instead of overwriting existing header key, it added another map entry.
 
 ### SDK Enhancements
 

aws/request/handlers.go

@@ -338,6 +338,6 @@ type withRequestHeader map[string]string
 
 func (h withRequestHeader) SetRequestHeaders(r *Request) {
 	for k, v := range h {
-		r.HTTPRequest.Header[k] = []string{v}
+		r.HTTPRequest.Header.Set(k, v)
 	}
 }

aws/request/handlers_test.go

@@ -1,6 +1,7 @@
 package request_test
 
 import (
+	"net/http"
 	"reflect"
 	"testing"
 
@@ -197,6 +198,39 @@ func TestStopHandlers(t *testing.T) {
 	}
 }
 
+func TestWithSetRequestHeaders(t *testing.T) {
+	fn := request.WithSetRequestHeaders(map[string]string{
+		"x-foo-bar": "abc123",
+		"X-Bar-foo": "efg456",
+	})
+
+	req := &request.Request{HTTPRequest: &http.Request{Header: http.Header{}}}
+	fn(req)
+
+	expect := map[string][]string{
+		"X-Foo-Bar": {"abc123"},
+		"X-Bar-Foo": {"efg456"},
+	}
+
+	if e, a := len(req.HTTPRequest.Header), len(expect); e != a {
+		t.Fatalf("expect %v headers, got %v", e, a)
+	}
+	for k, expectVs := range expect {
+		actualVs, ok := req.HTTPRequest.Header[k]
+		if !ok {
+			t.Errorf("expect %v header", k)
+		}
+		if e, a := len(expectVs), len(actualVs); e != a {
+			t.Fatalf("expect %v values for %v, got %v", e, k, a)
+		}
+		for i, expectV := range expectVs {
+			if e, a := expectV, actualVs[i]; e != a {
+				t.Errorf("expect %v[%d] to be %v, got %v", k, i, e, a)
+			}
+		}
+	}
+}
+
 func BenchmarkNewRequest(b *testing.B) {
 	svc := s3.New(unit.Session)