feat: add tests for filter methods

contracts/contracts/LogsProducer.sol

@@ -0,0 +1,21 @@
+// SPDX-License-numberOfLogsentifier: MIT
+
+pragma solidity ^0.8.6;
+
+contract LogsProducer {
+    event Event (
+        uint256 indexed nameOfLogs,
+        uint256 indexed numberOfLogs
+        // address sender
+    );
+
+    function produce(uint256 nameOfLogs, uint256 numberOfLogs) public {
+        for (uint i = 0; i < numberOfLogs; i++) {
+            emit Event(
+                nameOfLogs,
+                numberOfLogs
+                // msg.sender
+            );
+        }
+    }
+}

contracts/hardhat.config.js

@@ -60,7 +60,11 @@ module.exports = {
       accounts: [`0x${TEST_PK1}`]
     },
     hardhat: {
-      hardfork: "berlin"
+      hardfork: "berlin",
+      mining: {
+        auto: true,
+        interval: 1000
+      }
     }
   },
   mocha: {

contracts/test/logs.js

@@ -0,0 +1,178 @@
+const {expect} = require("chai");
+const {ethers, web3} = require("hardhat");
+
+describe("eth_getFilterChanges", function () {
+    // NOTE: `eth_getFilterChanges` returns a list of block hashes for a block filter, while a part of hashes
+    // may not exist on the canonical chain, so `getBlock()` will return `null` for them.
+    it("eth_getFilterChanges with BlockFilter", async function () {
+        // 1. Create a block filter
+        const filterId = await ethers.provider.send("eth_newBlockFilter", []);
+
+        // 2. Deploy contract and make a call
+        const logsProducer = await ethers.getContractFactory("LogsProducer");
+        const contract = await logsProducer.deploy();
+        await contract.deployed();
+
+        const nameOfLogs = 1;
+        const numberOfLogs = 1;
+        await (await contract.produce(nameOfLogs, numberOfLogs)).wait(2);
+
+        // 3. eth_getFilterChanges should return a list of block hashes, check count and order(asc) of them
+        const blockHashes = await ethers.provider.send("eth_getFilterChanges", [filterId]);
+        let canonicalBlockNumbers = [];
+        for (const blockHash of blockHashes) {
+            const number = (await ethers.provider.getBlock(blockHash))?.number;
+            if (number != null) {
+                canonicalBlockNumbers.push(number);
+            }
+        }
+        expect(canonicalBlockNumbers).deep.eq([...canonicalBlockNumbers].sort());
+        expect(canonicalBlockNumbers.length).gte(2);
+    });
+
+    it("eth_getFilterChanges with filter using address and topics", async function () {
+        // 1. Deploy contract
+        const logsProducer = await ethers.getContractFactory("LogsProducer");
+        const contract = await logsProducer.deploy();
+        await contract.deployed();
+
+        // 2. Create a filter with address and topics.
+        //
+        // topics: [signature of event name, $nameOfLogs, $numberOfLogs]
+        const nameOfLogs = 2;
+        const numberOfLogs = 2;
+        const topics = contract.filters.Event(
+            "0x" + ("0".repeat(64) + nameOfLogs.toString(16)).slice(-64),
+            "0x" + ("0".repeat(64) + numberOfLogs.toString(16)).slice(-64),
+        ).topics;
+        const address = contract.address;
+        const fromBlock = null;
+        const filterId = await ethers.provider.send("eth_newFilter", [{address, topics, fromBlock}]);
+
+        const fn = async () => {
+            // 3. Emit $numberOfLogs logs
+            const tx = await contract.produce(nameOfLogs, numberOfLogs);
+            await tx.wait(2);
+
+            // 4. We should get `$numberOfLogs` results with order(asc) by id desc
+            const receipt = await ethers.provider.getTransactionReceipt(tx.hash);
+            const receiptLogIds = receipt.logs.map(log => log.logIndex);
+            const logs = await ethers.provider.send("eth_getFilterChanges", [filterId]);
+            expect(receiptLogIds.length).eq(numberOfLogs);
+            expect(receiptLogIds).deep.eq([...receiptLogIds].sort());
+            expect(receiptLogIds).deep.eq(logs.map(log => Number(log.logIndex)));
+
+            // 5. eth_getFilterChanges should return [] now because the lastPoll is updated
+            expect(await ethers.provider.send("eth_getFilterChanges", [filterId])).deep.eq([]);
+        }
+        await fn();
+        await fn();
+    });
+});
+
+describe("eth_getFilterLogs", function () {
+    // NOTE: `eth_getFilterLogs` returns [] for eth_newBlockFilter
+    it("eth_getFilterLogs with BlockFilter", async function () {
+        // 1. Create a block filter
+        const filterId = await ethers.provider.send("eth_newBlockFilter", []);
+
+        // 2. Deploy contract and make a call
+        const nameOfLogs = 3;
+        const numberOfLogs = 3;
+        const logsProducer = await ethers.getContractFactory("LogsProducer");
+        const contract = await logsProducer.deploy();
+        await contract.deployed();
+        await (await contract.produce(nameOfLogs, numberOfLogs)).wait(2);
+
+        // 3. eth_getFilterLogs should return []
+        const logs = await ethers.provider.send("eth_getFilterLogs", [filterId]);
+        expect(logs).deep.eq([])
+    })
+
+    it("eth_getFilterLogs with filter using address and topics", async function () {
+        // 1. Deploy contract
+        const logsProducer = await ethers.getContractFactory("LogsProducer");
+        const contract = await logsProducer.deploy();
+        await contract.deployed();
+
+        // 2. Create a filter with address and topics.
+        //
+        // topics: [signature of event name, $nameOfLogs, $numberOfLogs]
+        const nameOfLogs = 2;
+        const numberOfLogs = 2;
+        const topics = contract.filters.Event(
+            "0x" + ("0".repeat(64) + nameOfLogs.toString(16)).slice(-64),
+            "0x" + ("0".repeat(64) + numberOfLogs.toString(16)).slice(-64),
+        ).topics;
+        const address = contract.address;
+        const fromBlock = null;
+        const filterId = await ethers.provider.send("eth_newFilter", [{address, topics, fromBlock}]);
+
+        const fn = async () => {
+            // 3. Emit $numberOfLogs logs
+            const tx = await contract.produce(nameOfLogs, numberOfLogs);
+            await tx.wait(2);
+
+            // 4. We should get `$numberOfLogs` results with order(asc) by id desc
+            const receipt = await ethers.provider.getTransactionReceipt(tx.hash);
+            const receiptLogIds = receipt.logs.map(log => log.logIndex);
+            const logs = await ethers.provider.send("eth_getFilterLogs", [filterId]);
+            expect(receiptLogIds.length).eq(numberOfLogs);
+            expect(receiptLogIds).deep.eq([...receiptLogIds].sort());
+            expect(receiptLogIds).deep.eq(logs.map(log => Number(log.logIndex)));
+
+            // 5. eth_getFilterChanges should return [] now because the lastPoll is updated
+            expect(await ethers.provider.send("eth_getFilterLogs", [filterId])).deep.eq([]);
+        }
+        await fn();
+        await fn();
+    })
+})
+
+describe("eth_getLogs", function () {
+    it("eth_getLogs with filter using address and topics", async function () {
+        // 1. Deploy contract and wait 2 blocks generated
+        const logsProducer = await ethers.getContractFactory("LogsProducer");
+        const contract = await logsProducer.deploy();
+        await contract.deployed();
+
+        const nameOfLogs = 4;
+        const numberOfLogs = 4;
+        const tx = await contract.produce(nameOfLogs, numberOfLogs);
+
+        // IMPORTANT NOTE:
+        // To eliminate the effect of "instant finality", we should wait at least 2 blocks generated!
+        await tx.wait(2);
+
+        const receipt = await ethers.provider.getTransactionReceipt(tx.hash);
+        const receiptLogIds = receipt.logs.map(log => log.logIndex);
+        const receiptBlockNumber = "0x" + receipt.blockNumber.toString(16);
+        const receiptBlockNumberAdd1 = "0x" + (receipt.blockNumber + 1).toString(16);
+        expect(receiptLogIds).deep.eq([...receiptLogIds].sort());
+
+        const topics = contract.filters.Event(
+            "0x" + ("0".repeat(64) + nameOfLogs.toString(16)).slice(-64),
+            "0x" + ("0".repeat(64) + numberOfLogs.toString(16)).slice(-64),
+        ).topics;
+        const address = contract.address;
+        const cases = [
+            {fromBlock: undefined, toBlock: undefined, expected: receiptLogIds},
+            {fromBlock: "earliest", toBlock: undefined, expected: receiptLogIds},
+            {fromBlock: "latest", toBlock: undefined, expected: []},
+            {fromBlock: "pending", toBlock: undefined, expected: []},
+            {fromBlock: receiptBlockNumber, toBlock: undefined, expected: receiptLogIds},
+            {fromBlock: receiptBlockNumberAdd1, toBlock: undefined, expected: []},
+            {fromBlock: undefined, toBlock: "earliest", expected: []},
+            {fromBlock: "earliest", toBlock: receiptBlockNumber, expected: receiptLogIds},
+            {fromBlock: receiptBlockNumber, toBlock: receiptBlockNumber, expected: receiptLogIds},
+            {fromBlock: receiptBlockNumberAdd1, toBlock: receiptBlockNumber, expected: []},
+            {fromBlock: undefined, toBlock: undefined, blockHash: receipt.blockHash, expected: receiptLogIds}
+        ];
+        for (const {fromBlock, toBlock, blockHash, expected} of cases) {
+            const filter = {address, topics, fromBlock, toBlock, blockHash};
+            const logs = await ethers.provider.send("eth_getLogs", [filter]);
+            expect(logs.length, `filter: ${JSON.stringify(filter)}`).eq(expected.length);
+            expect(logs.map(log => Number(log.logIndex)), `filter: ${JSON.stringify(filter)}`).deep.eq(expected);
+        }
+    })
+})