A brief discussion on WebSocket interface testing

What is WebSocket

WebSocket is a protocol based on full-duplex communication on a single TCP connection. It solves the shortcoming of HTTP protocol that is not suitable for real-time communication. Compared with HTTP protocol, WebSocket protocol realizes persistent network communication, can realize long connection between client and server, and can carry out two-way real-time communication. The protocol name is "ws".

WebSocket makes data exchange between clients and servers much simpler, allowing the server to actively push data to the client. In the WebSocket API, the browser and the server only need to complete a handshake, and then a persistent connection can be directly established between the two, and two-way data transmission can be carried out. In the WebSocket API, the browser and the server only need to complete a handshake, and then a fast channel is formed between the browser and the server. Data can be directly transmitted between the two.

HTTP vs WebSocket

Features of WebSocket

• Built on the TCP protocol, the server-side implementation is relatively easy.
• It has good compatibility with HTTP protocol. The default ports are also 80 and 443, and the handshake phase uses HTTP protocol, so it is not easy to block during the handshake and can pass through various HTTP proxy servers.
• The data format is relatively lightweight, with low performance overhead and efficient communication.
• You can send text or binary data.
• There is no same-origin restriction, and the client can communicate with any server.
• The protocol identifier is ws (or wss if encrypted), and the server URL is the URL.

 ws://example.com:80/some/path

What is a Socket?

Two programs on the network exchange data through a two-way communication connection. One end of this connection is called a Socket, so at least a pair of port numbers are required to establish a network communication connection.

The essence of Socket is the encapsulation of TCP/IP protocol stack. It provides an interface for TCP or UDP programming, not another protocol. Through Socket, you can use TCP/IP protocol.