Add decoding of arrays

Author: Mordil

Sources/NIORedis/Coders/RedisDataDecoder.swift

@@ -59,6 +59,8 @@ extension RedisDataDecoder {
             return .parsed
         case .dollar:
             return try _parseBulkString(at: &position, from: buffer)
+        case .asterisk:
+            return try _parseArray(at: &position, from: buffer)
         default: return .notYetParsed
         }
     }
@@ -139,6 +141,31 @@ extension RedisDataDecoder {
 
         return .parsed // bulkString(Data(bytes[ ..<(size - 1) ]))
     }
+
+    /// See https://redis.io/topics/protocol#resp-arrays
+    func _parseArray(at position: inout Int, from buffer: ByteBuffer) throws -> _RedisDataDecodingState {
+        guard let arraySize = try _parseInteger(at: &position, from: buffer) else { return .notYetParsed }
+        #warning("TODO: return null array")
+        guard arraySize > -1 else { return .parsed }
+        #warning("TODO: return empty array")
+        guard arraySize > 0 else { return .parsed }
+
+        var array = [_RedisDataDecodingState](repeating: .notYetParsed, count: arraySize)
+        for index in 0..<arraySize {
+            guard buffer.readableBytes - position > 0 else { return .notYetParsed }
+
+            let parseResult = try _parse(at: &position, from: buffer)
+            switch parseResult {
+            case .parsed:
+                array[index] = parseResult
+            default:
+                return .notYetParsed
+            }
+        }
+
+        #warning("TODO: Mapping to data and return the array of values")
+        return .parsed
+    }
 }
 
 private extension ByteBuffer {

Tests/NIORedisTests/RedisDataDecoder+ParsingTests.swift

@@ -41,6 +41,18 @@ final class RedisDataDecoderParsingTests: XCTestCase {
         ])
     }
 
+    func testParsing_with_arrays() throws {
+        try parseTest_singleValue(input: "*1\r\n+!\r\n")
+        try parseTest_singleValue(input: "*2\r\n*1\r\n:1\r\n:3\r\n")
+        try parseTest_singleValue(input: "*0\r\n".convertedToData())
+        try parseTest_singleValue(input: "*-1\r\n".convertedToData())
+    }
+
+    func testParsing_with_arrays_recursively() throws {
+        try parseTest_recursive(withChunks: ["*2\r", "\n+a\r\n+a\r\n*", "0\r\n"])
+        try parseTest_recursive(withChunks: ["*-1\r".convertedToData(), "\n".convertedToData()])
+    }
+
     /// See parse_Test_singleValue(input:) String
     private func parseTest_singleValue(input: String) throws {
         try parseTest_singleValue(input: input.convertedToData())
@@ -208,7 +220,7 @@ extension RedisDataDecoderParsingTests {
     }
 
     func testParsing_bulkString_handlesLargeSizes() throws {
-        let bytes = [UInt8].init(repeating: .dollar, count: 10_000_000)
+        let bytes = [UInt8].init(repeating: .dollar, count: 1_000_000)
         let data = "$\(bytes.count)\r\n".convertedToData() + Data(bytes: bytes) + "\r\n".convertedToData()
         XCTAssertEqual(try parseTestBulkString(data), .parsed)
     }
@@ -227,6 +239,55 @@ extension RedisDataDecoderParsingTests {
     }
 }
 
+// MARK: Array Parsing
+
+extension RedisDataDecoderParsingTests {
+    func testParsing_array_whenNull_returnsNil() {
+        XCTAssertEqual(try parseTestArray("*-1\r\n"), .parsed)
+    }
+
+    func testParsing_array_whenEmpty_returnsEmpty() {
+        XCTAssertEqual(try parseTestArray("*0\r\n"), .parsed)
+    }
+
+    func testParsing_array_handlesLargeSizes() {
+        let range = 0..<1000
+        var data = "*\(range.endIndex)\r\n".convertedToData()
+        range.forEach { _ in
+            data += "$5\r\n".convertedToData()
+            data += Data(bytes: [0xaa, 0xbb, 0xcc, 0xab, 0xff])
+            data += "\r\n".convertedToData()
+        }
+
+        XCTAssertEqual(try parseTestArray(data), .parsed)
+    }
+
+    func testParsing_array_handlesMixedTypes() {
+        XCTAssertEqual(try parseTestArray("*3\r\n:3\r\n+OK\r\n$1\r\na\r\n"), .parsed)
+    }
+
+    func testParsing_array_handlesNullElements() {
+        XCTAssertEqual(try parseTestArray("*3\r\n:3\r\n$-1\r\n:30\r\n"), .parsed)
+    }
+
+    func testParsing_array_handlesNestedArrays() {
+        XCTAssertEqual(try parseTestArray("*2\r\n:3\r\n*2\r\n:30\r\n:15\r\n"), .parsed)
+    }
+
+    private func parseTestArray(_ input: String) throws -> RedisDataDecoder._RedisDataDecodingState {
+        return try parseTestArray(input.convertedToData())
+    }
+
+    private func parseTestArray(_ input: Data) throws -> RedisDataDecoder._RedisDataDecodingState {
+        var buffer = allocator.buffer(capacity: input.count)
+        buffer.write(bytes: input)
+
+        var position = 1 // "trim" token
+
+        return try RedisDataDecoder()._parseArray(at: &position, from: buffer)
+    }
+}
+
 extension RedisDataDecoderParsingTests {
     static var allTests = [
         ("testParsing_with_simpleString", testParsing_with_simpleString),
@@ -235,6 +296,8 @@ extension RedisDataDecoderParsingTests {
         ("testParsing_with_integer_recursively", testParsing_with_integer_recursively),
         ("testParsing_with_bulkString", testParsing_with_bulkString),
         ("testParsing_with_bulkString_recursively", testParsing_with_bulkString_recursively),
+        ("testParsing_with_arrays", testParsing_with_arrays),
+        ("testParsing_with_arrays_recursively", testParsing_with_arrays_recursively),
         ("testParsing_simpleString_missingEndings_returnsNil", testParsing_simpleString_missingEndings_returnsNil),
         ("testParsing_simpleString_withNoContent_returnsEmpty", testParsing_simpleString_withNoContent_returnsEmpty),
         ("testParsing_simpleString_withContent_returnsExpectedContent", testParsing_simpleString_withContent_returnsExpectedContent),
@@ -247,5 +310,11 @@ extension RedisDataDecoderParsingTests {
         ("testParsing_bulkString_withNull_returnsNil", testParsing_bulkString_withNull_returnsNil),
         ("testParsing_bulkString_handlesRawBytes", testParsing_bulkString_handlesRawBytes),
         ("testParsing_bulkString_handlesLargeSizes", testParsing_bulkString_handlesLargeSizes),
+        ("testParsing_array_whenNull_returnsNil", testParsing_array_whenNull_returnsNil),
+        ("testParsing_array_whenEmpty_returnsEmpty", testParsing_array_whenEmpty_returnsEmpty),
+        ("testParsing_array_handlesLargeSizes", testParsing_array_handlesLargeSizes),
+        ("testParsing_array_handlesMixedTypes", testParsing_array_handlesMixedTypes),
+        ("testParsing_array_handlesNullElements", testParsing_array_handlesNullElements),
+        ("testParsing_array_handlesNestedArrays", testParsing_array_handlesNestedArrays),
     ]
 }