feat: implement eth_getLogs

Sources/Web3Core/Contract/ContractProtocol.swift

@@ -280,6 +280,13 @@ extension DefaultContractProtocol {
         return encodedData
     }
 
+    public func event(_ event: String, parameters: [Any]) -> [EventFilterParameters.Topic?] {
+        guard let event = events[event] else {
+            return []
+        }
+        return event.encodeParameters(parameters)
+    }
+
     public func parseEvent(_ eventLog: EventLog) -> (eventName: String?, eventData: [String: Any]?) {
         for (eName, ev) in self.events {
             if !ev.anonymous {

Sources/Web3Core/EthereumABI/ABIElements.swift

@@ -211,13 +211,85 @@ extension ABI.Element.Function {
     }
 }
 
-// MARK: - Event logs decoding
+// MARK: - Event logs decoding & encoding
 
 extension ABI.Element.Event {
     public func decodeReturnedLogs(eventLogTopics: [Data], eventLogData: Data) -> [String: Any]? {
         guard let eventContent = ABIDecoder.decodeLog(event: self, eventLogTopics: eventLogTopics, eventLogData: eventLogData) else { return nil }
         return eventContent
     }
+
+    public static func encodeTopic(input: ABI.Element.Event.Input, value: Any) -> EventFilterParameters.Topic? {
+        switch input.type {
+        case .string:
+            guard let string = value as? String else {
+                return nil
+            }
+            return .string(string.sha3(.keccak256).addHexPrefix())
+        case .dynamicBytes:
+            guard let data = ABIEncoder.convertToData(value) else {
+                return nil
+            }
+            return .string(data.sha3(.keccak256).toHexString().addHexPrefix())
+        case .bytes(length: _):
+            guard let data = ABIEncoder.convertToData(value), let data = data.setLengthLeft(32) else {
+                return nil
+            }
+            return .string(data.toHexString().addHexPrefix())
+        case .address, .uint(bits: _), .int(bits: _), .bool:
+            guard let encoded = ABIEncoder.encodeSingleType(type: input.type, value: value) else {
+                return nil
+            }
+            return .string(encoded.toHexString().addHexPrefix())
+        default:
+            guard let data = try? ABIEncoder.abiEncode(value).setLengthLeft(32) else {
+                return nil
+            }
+            return .string(data.toHexString().addHexPrefix())
+        }
+    }
+
+    public func encodeParameters(_ parameters: [Any?]) -> [EventFilterParameters.Topic?] {
+        guard parameters.count <= inputs.count else {
+            // too many arguments for fragment
+            return []
+        }
+        var topics: [EventFilterParameters.Topic?] = []
+
+        if !anonymous {
+            topics.append(.string(topic.toHexString().addHexPrefix()))
+        }
+
+        for (i, p) in parameters.enumerated() {
+            let input = inputs[i]
+            if !input.indexed {
+                // cannot filter non-indexed parameters; must be null
+                return []
+            }
+            if p == nil {
+                topics.append(nil)
+            } else if input.type.isArray || input.type.isTuple {
+                // filtering with tuples or arrays not supported
+                return []
+            } else if let p = p as? Array<Any> {
+                topics.append(.strings(p.map { Self.encodeTopic(input: input, value: $0) }))
+            } else {
+                topics.append(Self.encodeTopic(input: input, value: p!))
+            }
+        }
+
+        // Trim off trailing nulls
+        while let last = topics.last {
+            if last == nil {
+                topics.removeLast()
+            } else if case .string(let string) = last, string == nil {
+                topics.removeLast()
+            } else {
+                break
+            }
+        }
+        return topics
+    }
 }
 
 // MARK: - Function input/output decoding

Sources/Web3Core/Transaction/EventfilterParameters.swift

@@ -50,8 +50,8 @@ extension EventFilterParameters {
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(fromBlock.description, forKey: .fromBlock)
         try container.encode(toBlock.description, forKey: .toBlock)
-        try container.encode(address.description, forKey: .address)
-        try container.encode(topics.textRepresentation, forKey: .topics)
+        try container.encode(address, forKey: .address)
+        try container.encode(topics, forKey: .topics)
     }
 }
 
@@ -96,6 +96,17 @@ extension EventFilterParameters {
         case string(String?)
         case strings([Topic?]?)
 
+        public func encode(to encoder: Encoder) throws {
+            switch self {
+            case let .string(s):
+                var container = encoder.singleValueContainer()
+                try container.encode(s)
+            case let .strings(ss):
+                var container = encoder.unkeyedContainer()
+                try container.encode(contentsOf: ss ?? [])
+            }
+        }
+
         var rawValue: String {
             switch self {
             case let .string(string):

Sources/web3swift/EthereumAPICalls/Ethereum/IEth+Defaults.swift

@@ -130,6 +130,12 @@ public extension IEth {
     }
 }
 
+public extension IEth {
+    func getLogs(eventFilter: EventFilterParameters) async throws -> [EventLog] {
+        try await APIRequest.sendRequest(with: self.provider, for: .getLogs(eventFilter)).result
+    }
+}
+
 public extension IEth {
     func send(_ transaction: CodableTransaction) async throws -> TransactionSendingResult {
         let request = APIRequest.sendTransaction(transaction)

Sources/web3swift/EthereumAPICalls/Ethereum/IEth.swift

@@ -25,6 +25,8 @@ public protocol IEth {
 
     func code(for address: EthereumAddress, onBlock: BlockNumber) async throws -> Hash
 
+    func getLogs(eventFilter: EventFilterParameters) async throws -> [EventLog]
+
     func gasPrice() async throws -> BigUInt
 
     func getTransactionCount(for address: EthereumAddress, onBlock: BlockNumber) async throws -> BigUInt

Tests/web3swiftTests/localTests/EventTests.swift

@@ -0,0 +1,90 @@
+//
+//  EventTests.swift
+//
+//
+//  Created by liugang zhang on 2023/8/24.
+//
+
+import XCTest
+import Web3Core
+import BigInt
+
+@testable import web3swift
+
+class EventTests: XCTestCase {
+
+    /// Solidity event allows up to 3 indexed field, this is just for test.
+    let testEvent = """
+    [{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bytes32","name":"userOpHash","type":"bytes32"},{"indexed":true,"internalType":"address","name":"sender","type":"address"},{"indexed":true,"internalType":"string","name":"a","type":"string"},{"indexed":true,"internalType":"bool","name":"b","type":"bool"},{"indexed":true,"internalType":"bytes","name":"c","type":"bytes"},{"indexed":true,"internalType":"uint256","name":"d","type":"uint256"}],"name":"UserOperationEvent","type":"event"}]
+    """
+
+    func testEncodeTopicToJSON() throws {
+        let encoder = JSONEncoder()
+        let t1: [EventFilterParameters.Topic] = []
+        let t2: [EventFilterParameters.Topic] = [.string(nil)]
+        let t3: [EventFilterParameters.Topic] = [.strings([.string(nil), .string("1")])]
+        let t4: [EventFilterParameters.Topic] = [.strings([nil, .string("1")])]
+        XCTAssertNoThrow(try encoder.encode(t1))
+        XCTAssertNoThrow(try encoder.encode(t2))
+        XCTAssertNoThrow(try encoder.encode(t3))
+        XCTAssertNoThrow(try encoder.encode(t4))
+
+        let topics: [EventFilterParameters.Topic] = [
+            .string("1"),
+            .strings([
+                .string("2"),
+                .string("3"),
+            ]
+        )]
+        let encoded = try encoder.encode(topics)
+        let json = try JSONSerialization.jsonObject(with: encoded)
+        XCTAssertEqual(json as? NSArray, ["1", ["2", "3"]])
+    }
+
+    func testEncodeLogs() throws {
+        let contract = try EthereumContract(testEvent)
+        let topic = contract.events["UserOperationEvent"]!.topic
+        let logs = contract.events["UserOperationEvent"]!.encodeParameters(
+            [
+                "0x2c16c07e1c68d502e9c7ad05f0402b365671a0e6517cb807b2de4edd95657042",
+                "0x581074D2d9e50913eB37665b07CAFa9bFFdd1640",
+                "hello,world",
+                true,
+                "0x02c16c07e1c68d50",
+                nil
+            ]
+        )
+        XCTAssertEqual(logs.count, 6)
+
+        XCTAssertTrue(logs[0] == topic.toHexString().addHexPrefix())
+        XCTAssertTrue(logs[1] == "0x2c16c07e1c68d502e9c7ad05f0402b365671a0e6517cb807b2de4edd95657042")
+        XCTAssertTrue(logs[2] == "0x000000000000000000000000581074d2d9e50913eb37665b07cafa9bffdd1640")
+        XCTAssertTrue(logs[3] == "0xab036729af8b8f9b610af4e11b14fa30c348f40c2c230cce92ef6ef37726fee7")
+        XCTAssertTrue(logs[4] == "0x0000000000000000000000000000000000000000000000000000000000000001")
+        XCTAssertTrue(logs[5] == "0x56f5a6cba57d26b32db8dc756fda960dcd3687770a300575a5f8107591eff63f")
+    }
+
+    func testEncodeTopic() throws {
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .string, indexed: true), value: "hello,world") == "0xab036729af8b8f9b610af4e11b14fa30c348f40c2c230cce92ef6ef37726fee7")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .address, indexed: true), value: "0x003e36550908907c2a2da960fd19a419b9a774b7") == "0x000000000000000000000000003e36550908907c2a2da960fd19a419b9a774b7")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .address, indexed: true), value: EthereumAddress("0x003e36550908907c2a2da960fd19a419b9a774b7")!) == "0x000000000000000000000000003e36550908907c2a2da960fd19a419b9a774b7")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .bool, indexed: true), value: true) == "0x0000000000000000000000000000000000000000000000000000000000000001")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .bool, indexed: true), value: false) == "0x0000000000000000000000000000000000000000000000000000000000000000")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .uint(bits: 256), indexed: true), value: BigUInt("dbe20a", radix: 16)!) == "0x0000000000000000000000000000000000000000000000000000000000dbe20a")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .uint(bits: 256), indexed: true), value: "dbe20a") == "0x0000000000000000000000000000000000000000000000000000000000dbe20a")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .int(bits: 32), indexed: true), value: 100) == "0x0000000000000000000000000000000000000000000000000000000000000064")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .dynamicBytes, indexed: true), value: Data(hex: "6761766f66796f726b")) == "0xe0859ceea0a2fd2474deef2b2183f10f4c741ebba702e9a07d337522c0af55fb")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .bytes(length: 32), indexed: true), value: Data(hex: "6761766f66796f726b")) == "0x00000000000000000000000000000000000000000000006761766f66796f726b")
+        XCTAssertTrue(ABI.Element.Event.encodeTopic(input: .init(name: "", type: .bytes(length: 32), indexed: true), value: "0x6761766f66796f726b") == "0x00000000000000000000000000000000000000000000006761766f66796f726b")
+    }
+}
+
+private func ==(lhs: EventFilterParameters.Topic?, rhs: String?) -> Bool {
+    if let lhs = lhs, case .string(let string) = lhs {
+        return string == rhs
+    }
+    if lhs == nil && rhs == nil {
+        return true
+    }
+    return false
+}

Tests/web3swiftTests/remoteTests/EventFilterTests.swift

@@ -0,0 +1,46 @@
+//
+//  EventFilterTests.swift
+//
+//
+//  Created by liugang zhang on 2023/8/24.
+//
+
+import XCTest
+import Web3Core
+import BigInt
+import CryptoSwift
+@testable import web3swift
+
+class EventFilerTests: XCTestCase {
+
+    /// This test tx can be found at here:
+    /// https://etherscan.io/tx/0x1a1daac5b3158f16399baec9abba2c8a4b4b7ffea5992490079b6bfc4ce70004
+    func testErc20Transfer() async throws {
+        let web3 = try await Web3.InfuraMainnetWeb3(accessToken: Constants.infuraToken)
+        let address = EthereumAddress("0xdac17f958d2ee523a2206206994597c13d831ec7")!
+        let erc20 = ERC20(web3: web3, provider: web3.provider, address: address)
+
+        let topics = erc20.contract.contract.event("Transfer", parameters: [
+            "0x003e36550908907c2a2da960fd19a419b9a774b7"
+        ])
+
+        let parameters = EventFilterParameters(fromBlock: .exact(17983395), toBlock: .exact(17983395), address: [address], topics: topics)
+        let result = try await web3.eth.getLogs(eventFilter: parameters)
+
+        XCTAssertEqual(result.count, 1)
+
+        let log = result.first!
+        XCTAssertEqual(log.address.address.lowercased(), "0xdac17f958d2ee523a2206206994597c13d831ec7")
+        XCTAssertEqual(log.transactionHash.toHexString().lowercased(), "1a1daac5b3158f16399baec9abba2c8a4b4b7ffea5992490079b6bfc4ce70004")
+
+        let logTopics = log.topics.map { $0.toHexString() }
+        topics.compactMap { t -> String? in
+            if let t = t, case EventFilterParameters.Topic.string(let topic) = t {
+                return topic
+            }
+            return nil
+        }.forEach { t in
+            XCTAssertTrue(logTopics.contains(t.stripHexPrefix()))
+        }
+    }
+}