reinhardt-query 0.2.2

//! Redis RESP3 command output type.

/// A Redis command represented as a RESP3 array of bulk strings.
///
/// Created by command builders via [`CommandStatementBuilder::build`](super::command::CommandStatementBuilder::build).
/// Use [`to_resp3_bytes`](RespCommand::to_resp3_bytes) to obtain wire-format bytes
/// suitable for sending directly over a TCP connection to Redis.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct RespCommand {
	args: Vec<Vec<u8>>,
}

impl RespCommand {
	pub(crate) fn new(args: Vec<Vec<u8>>) -> Self {
		Self { args }
	}

	/// Returns the command arguments as a slice of byte vectors.
	pub fn args(&self) -> &[Vec<u8>] {
		&self.args
	}

	/// Consumes the command and returns the inner argument vector.
	pub fn into_args(self) -> Vec<Vec<u8>> {
		self.args
	}

	/// Serializes the command to RESP3 wire format.
	///
	/// Format: `*N\r\n` followed by N bulk strings (`$len\r\ndata\r\n`).
	pub fn to_resp3_bytes(&self) -> Vec<u8> {
		let mut buf = Vec::new();
		buf.extend_from_slice(format!("*{}\r\n", self.args.len()).as_bytes());
		for arg in &self.args {
			buf.extend_from_slice(format!("${}\r\n", arg.len()).as_bytes());
			buf.extend_from_slice(arg);
			buf.extend_from_slice(b"\r\n");
		}
		buf
	}
}

#[cfg(test)]
mod tests {
	use super::*;
	use rstest::*;

	#[rstest]
	fn test_resp3_bytes_set() {
		// Arrange
		let cmd = RespCommand::new(vec![
			b"SET".to_vec(),
			b"mykey".to_vec(),
			b"myvalue".to_vec(),
		]);

		// Act
		let bytes = cmd.to_resp3_bytes();

		// Assert
		assert_eq!(
			bytes,
			b"*3\r\n$3\r\nSET\r\n$5\r\nmykey\r\n$7\r\nmyvalue\r\n"
		);
	}

	#[rstest]
	fn test_args_returns_slice() {
		// Arrange
		let cmd = RespCommand::new(vec![b"PING".to_vec()]);

		// Assert
		assert_eq!(cmd.args(), &[b"PING".to_vec()]);
	}

	#[rstest]
	fn test_into_args_consumes() {
		// Arrange
		let cmd = RespCommand::new(vec![b"GET".to_vec(), b"k".to_vec()]);

		// Act
		let args = cmd.into_args();

		// Assert
		assert_eq!(args, vec![b"GET".to_vec(), b"k".to_vec()]);
	}

	#[rstest]
	fn test_resp3_bytes_single_arg() {
		// Arrange
		let cmd = RespCommand::new(vec![b"PING".to_vec()]);

		// Act
		let bytes = cmd.to_resp3_bytes();

		// Assert
		assert_eq!(bytes, b"*1\r\n$4\r\nPING\r\n");
	}
}