compare http and apigw spans in tests

contrib/internal/httptrace/httptrace.go

@@ -45,11 +45,11 @@ func StartRequestSpan(r *http.Request, opts ...ddtrace.StartSpanOption) (tracer.
 	inferredStartSpanOpts := make([]ddtrace.StartSpanOption, 0, 1)
 
 	spanParentCtx, spanParentErr := tracer.Extract(tracer.HTTPHeadersCarrier(r.Header))
-
 	var spanLinksCtx ddtrace.SpanContextWithLinks
-	if spanParentErr == nil && spanParentCtx.(ddtrace.SpanContextWithLinks) != nil {
-		// If there are span links as a result of context extraction, add them as a StartSpanOption
-		if spanLinksCtx = spanParentCtx.(ddtrace.SpanContextWithLinks); spanLinksCtx.SpanLinks() != nil {
+
+	if spanParentErr == nil {
+		if linksCtx, ok := spanParentCtx.(ddtrace.SpanContextWithLinks); ok {
+			spanLinksCtx = linksCtx
 			inferredStartSpanOpts = append(inferredStartSpanOpts, tracer.WithSpanLinks(spanLinksCtx.SpanLinks()))
 		}
 	}
@@ -87,8 +87,8 @@ func StartRequestSpan(r *http.Request, opts ...ddtrace.StartSpanOption) (tracer.
 				cfg.Parent = spanParentCtx
 			}
 
-			if spanParentErr != nil && !inferredProxySpanCreated {
-				cfg.SpanLinks = spanLinksCtx.SpanLinks()
+			if spanParentErr != nil && !inferredProxySpanCreated && spanLinksCtx != nil {
+				tracer.WithSpanLinks(spanLinksCtx.SpanLinks())(cfg)
 			}
 
 			for k, v := range ipTags {

contrib/internal/httptrace/httptrace_api_gateway_test.go

@@ -67,7 +67,6 @@ func TestInferredProxySpans(t *testing.T) {
 
 		client := &http.Client{}
 		req, err := http.NewRequest("GET", fmt.Sprintf("%s/", appListener.URL), nil)
-
 		assert := as.New(t)
 		assert.NoError(err)
 
@@ -91,6 +90,9 @@ func TestInferredProxySpans(t *testing.T) {
 		assert.Equal("aws.apigateway", gatewaySpan.OperationName())
 		assert.Equal("http.request", webReqSpan.OperationName())
 		assert.True(webReqSpan.ParentID() == gatewaySpan.SpanID())
+		assert.Equal(webReqSpan.Tag("http.status_code"), gatewaySpan.Tag("http.status_code"))
+		assert.Equal(webReqSpan.Tag("span.type"), gatewaySpan.Tag("span.type"))
+
 		for _, arg := range inferredHeaders {
 			header, tag := normalizer.HeaderTag(arg)
 
@@ -136,6 +138,8 @@ func TestInferredProxySpans(t *testing.T) {
 		assert.Equal("aws.apigateway", gatewaySpan.OperationName())
 		assert.Equal("http.request", webReqSpan.OperationName())
 		assert.True(webReqSpan.ParentID() == gatewaySpan.SpanID())
+		assert.Equal(webReqSpan.Tag("http.status_code"), gatewaySpan.Tag("http.status_code"))
+		assert.Equal(webReqSpan.Tag("span.type"), gatewaySpan.Tag("span.type"))
 		for _, arg := range inferredHeaders {
 			header, tag := normalizer.HeaderTag(arg)