Fix error handling with server shutdown

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

client.go

@@ -202,7 +202,7 @@ func (r *receiver) run(ctx context.Context, c *channel) {
 				if !ok {
 					// treat all errors that are not an rpc status as terminal.
 					// all others poison the connection.
-					r.err = err
+					r.err = filterCloseErr(err)
 					return
 				}
 			}
@@ -328,24 +328,23 @@ func (c *Client) recv(resp *Response, msg *message) error {
 //
 // This purposely ignores errors with a wrapped cause.
 func filterCloseErr(err error) error {
-	if err == nil {
+	switch {
+	case err == nil:
 		return nil
-	}
-
-	if err == io.EOF {
+	case err == io.EOF:
 		return ErrClosed
-	}
-
-	if strings.Contains(err.Error(), "use of closed network connection") {
+	case errors.Cause(err) == io.EOF:
 		return ErrClosed
-	}
-
+	case strings.Contains(err.Error(), "use of closed network connection"):
+		return ErrClosed
+	default:
 		// if we have an epipe on a write, we cast to errclosed
 		if oerr, ok := err.(*net.OpError); ok && oerr.Op == "write" {
 			if serr, ok := oerr.Err.(*os.SyscallError); ok && serr.Err == syscall.EPIPE {
 				return ErrClosed
 			}
 		}
+	}
 
 	return err
 }

server_test.go

@@ -351,7 +351,7 @@ func TestClientEOF(t *testing.T) {
 	}
 
 	// shutdown the server so the client stops receiving stuff.
-	if err := server.Shutdown(ctx); err != nil {
+	if err := server.Close(); err != nil {
 		t.Fatal(err)
 	}
 	if err := <-errs; err != ErrServerClosed {