reqwest-middleware/reqwest-retry/tests/all/helpers/simple_server.rs

143 lines
4.6 KiB
Rust

use async_std::io::ReadExt;
use async_std::io::WriteExt;
use async_std::net::{TcpListener, TcpStream};
use futures::stream::StreamExt;
use std::error::Error;
use std::fmt;
/// This is a simple server that returns the responses given at creation time: [`self.raw_http_responses`] following a round-robin mechanism.
pub struct SimpleServer {
listener: TcpListener,
port: u16,
host: String,
raw_http_responses: Vec<String>,
calls_counter: usize,
}
/// Request-Line = Method SP Request-URI SP HTTP-Version CRLF
struct Request<'a> {
method: &'a str,
uri: &'a str,
http_version: &'a str,
}
impl<'a> fmt::Display for Request<'a> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{} {} {}\r\n", self.method, self.uri, self.http_version)
}
}
impl SimpleServer {
/// Creates an instance of a [`SimpleServer`]
/// If [`port`] is None os Some(0), it gets randomly chosen between the available ones.
pub async fn new(
host: &str,
port: Option<u16>,
raw_http_responses: Vec<String>,
) -> Result<Self, anyhow::Error> {
let port = port.unwrap_or(0);
let listener = TcpListener::bind(format!("{}:{}", host, port)).await?;
let port = listener.local_addr()?.port();
Ok(Self {
listener,
port,
host: host.to_string(),
raw_http_responses,
calls_counter: 0,
})
}
/// Returns the uri in which the server is listening to.
pub fn uri(&self) -> String {
format!("http://{}:{}", self.host, self.port)
}
/// Starts the TcpListener and handles the requests.
pub async fn start(mut self) -> () {
while let Some(stream) = self.listener.incoming().next().await {
match stream {
Ok(stream) => {
match self.handle_connection(stream).await {
Ok(_) => (),
Err(e) => {
println!("Error handling connection: {}", e);
()
}
}
self.calls_counter = self.calls_counter + 1;
}
Err(e) => {
println!("Connection failed: {}", e);
()
}
}
}
}
/// Asyncrounously reads from the buffer and handle the request.
/// It first checks that the format is correct, then returns the response.
///
/// Returns a 400 if the request if formatted badly.
async fn handle_connection(&self, mut stream: TcpStream) -> Result<(), Box<dyn Error>> {
let mut buffer = vec![0; 1024];
stream.read(&mut buffer).await.unwrap();
let request = String::from_utf8_lossy(&buffer[..]);
let request_line = request.lines().next().unwrap();
let response = match Self::parse_request_line(&request_line) {
Ok(request) => {
println!("== Request == \n{}\n=============", request);
self.get_response().clone()
}
Err(e) => {
println!("++ Bad request: {} ++++++", e);
self.get_bad_request_response()
}
};
println!("-- Response --\n{}\n--------------", response.clone());
stream.write(response.as_bytes()).await.unwrap();
stream.flush().await.unwrap();
Ok(())
}
/// Parses the request line and checks that it contains the method, uri and http_version parts.
/// It does not check if the content of the checked parts is correct. It just checks the format (it contains enough parts) of the request.
fn parse_request_line(request: &str) -> Result<Request, Box<dyn Error>> {
let mut parts = request.split_whitespace();
let method = parts.next().ok_or("Method not specified")?;
let uri = parts.next().ok_or("URI not specified")?;
let http_version = parts.next().ok_or("HTTP version not specified")?;
Ok(Request {
method,
uri,
http_version,
})
}
/// Returns the response to use based on the calls counter.
/// It uses a round-robin mechanism.
fn get_response(&self) -> String {
let index = if self.calls_counter >= self.raw_http_responses.len() {
self.raw_http_responses.len() % self.calls_counter
} else {
self.calls_counter
};
self.raw_http_responses[index].clone()
}
/// Returns the raw HTTP response in case of a 400 Bad Request.
fn get_bad_request_response(&self) -> String {
"HTTP/1.1 400 Bad Request\r\n\r\n".to_string()
}
}