fix raising of ProxyError, add unit test

Author: eli-darkly

lib/sse_client/streaming_http.rb

@@ -61,7 +61,7 @@ def self.connect(uri, proxy, connect_timeout, read_timeout)
       # temporarily create a reader just for the proxy connect response
       proxy_reader = HTTPResponseReader.new(socket, read_timeout)
       if proxy_reader.status != 200
-        throw ProxyError, "proxy connection refused, status #{proxy_reader.status}"
+        raise ProxyError, "proxy connection refused, status #{proxy_reader.status}"
       end
 
       # start using TLS at this point if appropriate

spec/sse_client/sse_shared.rb

@@ -42,6 +42,7 @@ def setup_response(uri_path, &action)
 
 class StubProxyServer < StubHTTPServer
   attr_reader :request_count
+  attr_accessor :connect_status
 
   def initialize
     super
@@ -55,6 +56,9 @@ def create_server(port)
       AccessLog: [],
       Logger: NullLogger.new,
       ProxyContentHandler: proc do |req,res|
+        if !@connect_status.nil?
+          res.status = @connect_status
+        end
         @request_count += 1
       end
     )

spec/sse_client/streaming_http_spec.rb

@@ -118,6 +118,18 @@ def with_connection(cxn)
     end
   end
 
+  it "throws error if proxy responds with error status" do
+    with_server do |server|
+      server.setup_response("/") do |req,res|
+        res.body = body
+      end
+      with_server(StubProxyServer.new) do |proxy|
+        proxy.connect_status = 403
+        expect { subject.new(server.base_uri, proxy.base_uri, {}, 30, 30) }.to raise_error(SSE::ProxyError)
+      end
+    end
+  end
+
   # The following 2 tests were originally written to connect to an embedded HTTPS server made with
   # WEBrick. Unfortunately, some unknown problem prevents WEBrick's self-signed certificate feature
   # from working in JRuby 9.1 (but not in any other Ruby version). Therefore these tests currently