Merge pull request #16 from Mordil/general-commands

General commands

Author: Mordil

Sources/NIORedis/Commands/BasicCommands.swift

@@ -70,4 +70,40 @@ extension RedisConnection {
         return command("SET", arguments: [RESPValue(bulk: key), RESPValue(bulk: value)])
             .map { _ in return () }
     }
+
+    /// Echos the provided message through the Redis instance.
+    /// - Parameter message: The message to echo.
+    /// - Returns: The message sent with the command.
+    public func echo(_ message: String) -> EventLoopFuture<String> {
+        return send(command: "ECHO", with: [message])
+            .flatMapThrowing {
+                guard let response = $0.string else { throw RedisError.respConversion(to: String.self) }
+                return response
+            }
+    }
+
+    /// Pings the server, which will respond with a message.
+    /// - Parameter with: The optional message that the server should respond with.
+    /// - Returns: The provided message or Redis' default response of `"PONG"`.
+    public func ping(with message: String? = nil) -> EventLoopFuture<String> {
+        let arg = message != nil ? [message] : []
+        return send(command: "PING", with: arg)
+            .flatMapThrowing {
+                guard let response = $0.string else { throw RedisError.respConversion(to: String.self) }
+                return response
+            }
+    }
+
+    /// Swaps the data of two Redis database by their index ID.
+    /// - Parameters:
+    ///     - firstIndex: The index of the first database.
+    ///     - secondIndex: The index of the second database.
+    /// - Returns: `true` if the swap was successful.
+    public func swapdb(firstIndex: Int, secondIndex: Int) -> EventLoopFuture<Bool> {
+        return send(command: "SWAPDB", with: [firstIndex, secondIndex])
+            .flatMapThrowing {
+                guard let response = $0.string else { throw RedisError.respConversion(to: String.self) }
+                return response == "OK"
+            }
+    }
 }

Sources/NIORedis/RESP/RESPValueConvertible.swift

@@ -121,3 +121,20 @@ extension Array: RESPValueConvertible where Element: RESPValueConvertible {
         return RESPValue.array(elements)
     }
 }
+
+extension Optional: RESPValueConvertible where Wrapped: RESPValueConvertible {
+    public init?(_ value: RESPValue) {
+        guard !value.isNull else { return nil }
+        guard let wrapped = Wrapped(value) else { return nil }
+
+        self = .some(wrapped)
+    }
+
+    /// See `RESPValueConvertible.convertedToRESPValue()`.
+    public func convertedToRESPValue() -> RESPValue {
+        switch self {
+        case .none: return .null
+        case let .some(value): return value.convertedToRESPValue()
+        }
+    }
+}

Tests/NIORedisTests/Commands/BasicCommandsTests.swift

@@ -63,11 +63,50 @@ final class BasicCommandsTests: XCTestCase {
         XCTAssertNil(after)
     }
 
+    func test_ping() throws {
+        let first = try connection?.ping().wait()
+        XCTAssertEqual(first, "PONG")
+
+        let second = try connection?.ping(with: "My message").wait()
+        XCTAssertEqual(second, "My message")
+    }
+
+    func test_echo() throws {
+        let response = try connection?.echo("FIZZ_BUZZ").wait()
+        XCTAssertEqual(response, "FIZZ_BUZZ")
+    }
+
+    func test_swapdb() throws {
+        try connection?.set("first", to: "3").wait()
+        var first = try connection?.get("first").wait()
+        XCTAssertEqual(first, "3")
+
+        try connection?.select(1).wait()
+        var second = try connection?.get("first").wait()
+        XCTAssertEqual(second, nil)
+
+        try connection?.set("second", to: "100").wait()
+        second = try connection?.get("second").wait()
+        XCTAssertEqual(second, "100")
+
+        let success = try connection?.swapdb(firstIndex: 0, secondIndex: 1).wait()
+        XCTAssertEqual(success, true)
+
+        second = try connection?.get("first").wait()
+        XCTAssertEqual(second, "3")
+
+        try connection?.select(0).wait()
+        first = try connection?.get("second").wait()
+        XCTAssertEqual(first, "100")
+    }
+
     static var allTests = [
         ("test_select", test_select),
         ("test_set", test_set),
         ("test_get", test_get),
         ("test_expire", test_expire),
         ("test_delete", test_delete),
+        ("test_ping", test_ping),
+        ("test_echo", test_echo),
     ]
 }