BREAKING: Improve reply types

[uki00a]

Related to #189 and #80.

Summary

Currently, CommandExecutor returns replies in the form of a tuple of [<kind>, <raw data>] as follows:

  const reply = await redis.executor.exec("SET", "key", "a");
  assertEquals(reply, ["status", "OK"]);

In this PR, CommandExecutor is changed to return one of the following types:

• BulkReply
• StatusReply
• IntegerReply
• ArrayReply

Examples

  const reply = await redis.executor.exec("SET", "key", "a");
  assertEquals(reply.type, "status");
  assertEquals(reply.value(), "OK");

Motivation

This change is intended to support the following features in the future:

• Getting the raw data as a Uint8Array (get/set values from Uint8Array #189)
• RESP3 (RESP3 support #80)

Getting the raw data as a Uint8Array

The BulkReply type have buffer method which returns Uint8Array:

  const reply = await redis.executor.exec("GET", "redis");
  assert(reply.type === BULK_STRING_TYPE);
  const buffer = reply.buffer();

Changes

• Change return type of CommandExecutor#execute from tuple form to object form
• Rename Status to SimpleString