Add support for AUTH and SELECT protocols.

Author: ioquatix

async-redis.gemspec

@@ -23,9 +23,9 @@ Gem::Specification.new do |spec|
 
 	spec.required_ruby_version = ">= 3.1"
 
-	spec.add_dependency "async", [">= 1.8", "< 3.0"]
+	spec.add_dependency "async", "~> 2.10"
 	spec.add_dependency "async-pool", "~> 0.2"
 	spec.add_dependency "io-endpoint", "~> 0.10"
 	spec.add_dependency "io-stream", "~> 0.4"
-	spec.add_dependency "protocol-redis", "~> 0.8.0"
+	spec.add_dependency "protocol-redis", "~> 0.9"
 end

guides/getting-started/readme.md

@@ -17,13 +17,42 @@ $ bundle add async-redis
 ``` ruby
 require 'async/redis'
 
-endpoint = Async::Redis.local_endpoint
-client = Async::Redis::Client.new(endpoint)
+Async do
+	endpoint = Async::Redis.local_endpoint
+	client = Async::Redis::Client.new(endpoint)
+	puts client.info
+end
+```
+
+### Authenticated Protocol
+
+In order to authenticate, it is necessary to issue an `AUTH` command after connecting to the server. The `Async::Redis::Protocol::Authenticated` protocol class does this for you:
+
+``` ruby
+require 'async/redis'
+require 'async/redis/protocol/authenticated'
 
 Async do
+	endpoint = Async::Redis.local_endpoint
+	protocol = Async::Redis::Protocol::Authenticated.new(["username", "password"])
+	client = Async::Redis::Client.new(endpoint, protocol: protocol)
 	puts client.info
-ensure
-	client.close
+end
+```
+
+### Selected Database
+
+In order to select a database, it is necessary to issue a `SELECT` command after connecting to the server. The `Async::Redis::Protocol::Selected` protocol class does this for you:
+
+``` ruby
+require 'async/redis'
+require 'async/redis/protocol/selected'
+
+Async do
+	endpoint = Async::Redis.local_endpoint
+	protocol = Async::Redis::Protocol::Selected.new(1)
+	client = Async::Redis::Client.new(endpoint, protocol: protocol)
+	puts client.client_info
 end
 ```
 

lib/async/redis/protocol/authenticated.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2024, by Samuel Williams.
+
+require 'protocol/redis'
+
+module Async
+	module Redis
+		module Protocol
+			# Executes AUTH after the user has established a connection.
+			class Authenticated
+				# Authentication has failed for some reason.
+				class AuthenticationError < StandardError
+				end
+				
+				# Create a new authenticated protocol.
+				#
+				# @parameter credentials [Array] The credentials to use for authentication.
+				# @parameter protocol [Object] The delegated protocol for connecting.
+				def initialize(credentials, protocol: Async::Redis::Protocol::RESP2)
+					@credentials = credentials
+					@protocol = protocol
+				end
+				
+				# Create a new client and authenticate it.
+				def client(stream)
+					client = @protocol.client(stream)
+					
+					client.write_request(["AUTH", *@credentials])
+					response = client.read_response
+					
+					if response != "OK"
+						raise AuthenticationError, "Could not authenticate: #{response}"
+					end
+					
+					return client
+				end
+			end
+		end
+	end
+end

lib/async/redis/protocol/selected.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2024, by Samuel Williams.
+
+require 'protocol/redis'
+
+module Async
+	module Redis
+		module Protocol
+			# Executes AUTH after the user has established a connection.
+			class Selected
+				# Authentication has failed for some reason.
+				class SelectionError < StandardError
+				end
+				
+				# Create a new authenticated protocol.
+				#
+				# @parameter index [Integer] The database index to select.
+				# @parameter protocol [Object] The delegated protocol for connecting.
+				def initialize(index, protocol: Async::Redis::Protocol::RESP2)
+					@index = index
+					@protocol = protocol
+				end
+				
+				# Create a new client and authenticate it.
+				def client(stream)
+					client = @protocol.client(stream)
+					
+					client.write_request(["SELECT", @index])
+					response = client.read_response
+					
+					if response != "OK"
+						raise SelectionError, "Could not select database: #{response}"
+					end
+					
+					return client
+				end
+			end
+		end
+	end
+end

test/async/redis/protocol/authenticated.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2024, by Samuel Williams.
+
+require 'async/redis/client'
+require 'async/redis/protocol/authenticated'
+require 'sus/fixtures/async'
+
+describe Async::Redis::Protocol::Authenticated do
+	include Sus::Fixtures::Async::ReactorContext
+	
+	let(:endpoint) {Async::Redis.local_endpoint}
+	let(:credentials) {["testuser", "testpassword"]}
+	let(:protocol) {subject.new(credentials)}
+	let(:client) {Async::Redis::Client.new(endpoint, protocol: protocol)}
+	
+	before do
+		# Setup ACL user with limited permissions for testing.
+		admin_client = Async::Redis::Client.new(endpoint)
+		admin_client.call("ACL", "SETUSER", "testuser", "on", ">" + credentials[1], "+ping", "+auth")
+	ensure
+		admin_client.close
+	end
+	
+	after do
+		# Cleanup ACL user after tests.
+		admin_client = Async::Redis::Client.new(endpoint)
+		admin_client.call("ACL", "DELUSER", "testuser")
+		admin_client.close
+	end
+	
+	it "can authenticate and send allowed commands" do
+		response = client.call("PING")
+		expect(response).to be == "PONG"
+	end
+	
+	it "rejects commands not allowed by ACL" do
+		expect do
+			client.call("SET", "key", "value")
+		end.to raise_exception(Protocol::Redis::ServerError, message: be =~ /NOPERM/)
+	end
+end

test/async/redis/protocol/selected.rb

@@ -0,0 +1,23 @@
+
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2024, by Samuel Williams.
+
+require 'async/redis/client'
+require 'async/redis/protocol/selected'
+require 'sus/fixtures/async'
+
+describe Async::Redis::Protocol::Selected do
+	include Sus::Fixtures::Async::ReactorContext
+	
+	let(:endpoint) {Async::Redis.local_endpoint}
+	let(:index) {1}
+	let(:protocol) {subject.new(index)}
+	let(:client) {Async::Redis::Client.new(endpoint, protocol: protocol)}
+	
+	it "can select a specific database" do
+		response = client.client_info
+		expect(response[:db].to_i).to be == index
+	end
+end