// Copyright 2021-2025 The Connect Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package connect

import (
	"fmt"
	"testing"

	"connectrpc.com/connect/internal/assert"
	pingv1 "connectrpc.com/connect/internal/gen/connect/ping/v1"
)

func TestClientStreamIterator(t *testing.T) {
	t.Parallel()
	// The server's view of a client streaming RPC is an iterator. For safety,
	// and to match grpc-go's behavior, we should allocate a new message for each
	// iteration.
	stream := &ClientStream[pingv1.PingRequest]{
		conn: &nopStreamingHandlerConn{},
	}
	assert.True(t, stream.Receive())
	first := fmt.Sprintf("%p", stream.Msg())
	assert.True(t, stream.Receive())
	second := fmt.Sprintf("%p", stream.Msg())
	assert.NotEqual(t, first, second, assert.Sprintf("should allocate a new message for each iteration"))
}

type nopStreamingHandlerConn struct {
	StreamingHandlerConn
}

func (nopStreamingHandlerConn) Receive(msg any) error {
	return nil
}

func (nopStreamingHandlerConn) Spec() Spec {
	return Spec{}
}