fix: get remote file before appending default file names (#538)

Signed-off-by: Grant Linville <[email protected]>

Author: g-linville

pkg/loader/url.go

@@ -133,6 +133,20 @@ func loadURL(ctx context.Context, cache *cache.Client, base *source, name string
 
 func getWithDefaults(req *http.Request) ([]byte, error) {
 	originalPath := req.URL.Path
+
+	// First, try to get the original path as is. It might be an OpenAPI definition.
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusOK {
+		if toolBytes, err := io.ReadAll(resp.Body); err == nil && isOpenAPI(toolBytes) != 0 {
+			return toolBytes, nil
+		}
+	}
+
 	for i, def := range types.DefaultFiles {
 		base := path.Base(originalPath)
 		if !strings.Contains(base, ".") {