Function fetch_devtools_json

packages/server/src/devtools.rs:443–497

(host: &str, port: u16, path: &str)

}

async fn fetch_devtools_json(host: &str, port: u16, path: &str) -> Result<Value, String> {
    let address = format!("{host}:{port}");
    let mut stream = timeout(DEVTOOLS_DISCOVERY_TIMEOUT, TcpStream::connect(&address))
        .await
        .map_err(|_| format!("Timed out connecting to DevTools endpoint at {address}."))?
        .map_err(|error| format!("Unable to connect to DevTools endpoint at {address}: {error}"))?;

    let request = format!(
        "GET {path} HTTP/1.1\r\nHost: {address}\r\nAccept: application/json\r\nConnection: close\r\n\r\n"
    );
    timeout(
        DEVTOOLS_DISCOVERY_TIMEOUT,
        stream.write_all(request.as_bytes()),
    )
    .await
    .map_err(|_| format!("Timed out requesting DevTools {path}."))?
    .map_err(|error| format!("Unable to request DevTools {path}: {error}"))?;

    let mut response = Vec::new();
    let mut chunk = [0_u8; 8192];
    loop {
        let count = timeout(DEVTOOLS_DISCOVERY_TIMEOUT, stream.read(&mut chunk))
            .await
            .map_err(|_| format!("Timed out reading DevTools {path}."))?
            .map_err(|error| format!("Unable to read DevTools {path}: {error}"))?;
        if count == 0 {
            break;
        }
        response.extend_from_slice(&chunk[..count]);
        if response.len() > DEVTOOLS_MAX_RESPONSE_BYTES {
            return Err(format!("DevTools {path} response exceeded the size limit."));
        }
        if response_has_complete_body(&response) {
            break;
        }
    }

    let (headers, body) = split_http_response(&response)
        .ok_or_else(|| format!("DevTools {path} returned a malformed HTTP response."))?;
    let status = headers
        .lines()
        .next()
        .and_then(|line| line.split_whitespace().nth(1))
        .and_then(|status| status.parse::<u16>().ok())
        .unwrap_or(0);
    if !(200..300).contains(&status) {
        return Err(format!("DevTools {path} returned HTTP {status}."));
    }

    let body = content_length(&headers)
        .and_then(|length| body.get(..length))
        .unwrap_or(body);
    serde_json::from_slice(body)
        .map_err(|error| format!("DevTools {path} returned malformed JSON: {error}"))
}

async fn connect_loopback_devtools_service(
    port: u16,