Fixes for handling XML content (Azure#17578)

Author: jhendrixMSFT

sdk/azcore/CHANGELOG.md

@@ -7,6 +7,8 @@
 ### Breaking Changes
 
 ### Bugs Fixed
+* Include XML header when marshalling XML content.
+* Handle XML namespaces when searching for error code.
 
 ### Other Changes
 

sdk/azcore/internal/shared/response_error.go

@@ -75,7 +75,7 @@ func extractErrorCodeJSON(body []byte) string {
 
 func extractErrorCodeXML(body []byte) string {
 	// regular expression is much easier than dealing with the XML parser
-	rx := regexp.MustCompile(`<[c|C]ode>\s*(\w+)\s*<\/[c|C]ode>`)
+	rx := regexp.MustCompile(`<(?:\w+:)?[c|C]ode>\s*(\w+)\s*<\/(?:\w+:)?[c|C]ode>`)
 	res := rx.FindStringSubmatch(string(body))
 	if len(res) != 2 {
 		return ""

sdk/azcore/internal/shared/response_error_test.go

@@ -348,6 +348,43 @@ ERROR CODE: ContainerAlreadyExists
 	}
 }
 
+func TestNewResponseErrorErrorCodeHeaderXMLWithNamespace(t *testing.T) {
+	fakeURL, err := url.Parse("https://fakeurl.com/the/path?qp=removed")
+	if err != nil {
+		t.Fatal(err)
+	}
+	respHeader := http.Header{}
+	respHeader.Set("x-ms-error-code", "ContainerAlreadyExists")
+	err = NewResponseError(&http.Response{
+		Status:     "the system is down",
+		StatusCode: http.StatusInternalServerError,
+		Header:     respHeader,
+		Body:       io.NopCloser(strings.NewReader(`<?xml version="1.0" encoding="UTF-8" standalone="yes"?><m:Error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"><m:Code>ContainerAlreadyExists</m:Code><m:Message>The specified container already exists.\nRequestId:73b2473b-c1c8-4162-97bb-dc171bff61c9\nTime:2021-12-13T19:45:40.679Z</m:Message></m:Error>`)),
+		Request: &http.Request{
+			Method: http.MethodGet,
+			URL:    fakeURL,
+		},
+	})
+	re, ok := err.(*ResponseError)
+	if !ok {
+		t.Fatalf("unexpected error type %T", err)
+	}
+	if c := re.StatusCode; c != http.StatusInternalServerError {
+		t.Fatalf("unexpected status code %d", c)
+	}
+	const want = `GET https://fakeurl.com/the/path
+--------------------------------------------------------------------------------
+RESPONSE 500: the system is down
+ERROR CODE: ContainerAlreadyExists
+--------------------------------------------------------------------------------
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?><m:Error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"><m:Code>ContainerAlreadyExists</m:Code><m:Message>The specified container already exists.\nRequestId:73b2473b-c1c8-4162-97bb-dc171bff61c9\nTime:2021-12-13T19:45:40.679Z</m:Message></m:Error>
+--------------------------------------------------------------------------------
+`
+	if got := re.Error(); got != want {
+		t.Fatalf("\ngot:\n%s\nwant:\n%s\n", got, want)
+	}
+}
+
 func TestNewResponseErrorAllMissingXML(t *testing.T) {
 	fakeURL, err := url.Parse("https://fakeurl.com/the/path?qp=removed")
 	if err != nil {

sdk/azcore/runtime/request.go

@@ -106,6 +106,8 @@ func MarshalAsXML(req *policy.Request, v interface{}) error {
 	if err != nil {
 		return fmt.Errorf("error marshalling type %T: %s", v, err)
 	}
+	// inclue the XML header as some services require it
+	b = []byte(xml.Header + string(b))
 	return req.SetBody(shared.NopCloser(bytes.NewReader(b)), shared.ContentTypeAppXML)
 }