Propagate server response to exception

src/main/java/com/launchdarkly/eventsource/EventSource.java

@@ -261,7 +261,7 @@ private void connect() {
             }
           } else {
             logger.debug("Unsuccessful Response: " + response);
-            errorHandlerAction = dispatchError(new UnsuccessfulResponseException(response.code()));
+            errorHandlerAction = dispatchError(new UnsuccessfulResponseException(response));
           }
         } catch (EOFException eofe) {
           logger.warn("Connection unexpectedly closed.");

src/main/java/com/launchdarkly/eventsource/UnsuccessfulResponseException.java

@@ -1,27 +1,64 @@
 package com.launchdarkly.eventsource;
 
+import okhttp3.Protocol;
+import okhttp3.Request;
+import okhttp3.Response;
+
 /**
  * Exception class that means the remote server returned an HTTP error.
  */
 @SuppressWarnings("serial")
 public class UnsuccessfulResponseException extends Exception {
 
-  private final int code;
+  private final Response response;
 
   /**
    * Constructs an exception instance.
    * @param code the HTTP status
    */
+  @Deprecated
   public UnsuccessfulResponseException(int code) {
-    super("Unsuccessful response code received from stream: " + code);
-    this.code = code;
+    this(buildSurrogateResponse(code));
+  }
+
+  /**
+   * Constructs an exception instance.
+   * @param response {@link Response} provided by server
+   */
+  public UnsuccessfulResponseException(Response response) {
+    super("Unsuccessful response code received from stream: " + response.code());
+    this.response = response;
   }
 
   /**
    * Returns the HTTP status code.
    * @return the HTTP status
    */
   public int getCode() {
-    return code;
+    return response.code();
+  }
+
+  /**
+   * Returns the HTTP {@link Response}.
+   * @return the HTTP {@link Response}
+   */
+  public Response getResponse() {
+    return response;
+  }
+
+  /**
+   * Used for backward compatibility only: provide surrogate response for a given code
+   */
+  @Deprecated
+  private static Response buildSurrogateResponse(int code) {
+    return new Response.Builder()
+      .request(new Request.Builder()
+        .url("http://example.com")
+        .build()
+      )
+      .protocol(Protocol.HTTP_1_1)
+      .message("")
+      .code(code)
+      .build();
   }
 }