Adding script to poll transfer events

tests/get_transfer_events.js

@@ -0,0 +1,142 @@
+/*
+  This script starts polling for transfer events produced by one of the ERC721 contracts
+  associated to created collections, starting from the latest block, and logs to console.
+  Execute via:
+    $ npm ci && node get_transfer_events.js
+*/
+
+const { Web3 } = require('web3');
+const web3 = new Web3(new Web3.providers.HttpProvider("https://arrakis.gorengine.com/own"));
+
+// provide the ERC721 address associated to a created collection:
+const contractAddress = "0xFfffffFFfFFFfffFFFFFffFf0000000000000027";
+const contractABI = [
+	{
+		"anonymous": false,
+		"inputs": [
+			{
+				"indexed": true,
+				"internalType": "address",
+				"name": "_from",
+				"type": "address"
+			},
+			{
+				"indexed": true,
+				"internalType": "address",
+				"name": "_to",
+				"type": "address"
+			},
+			{
+				"indexed": true,
+				"internalType": "uint256",
+				"name": "_tokenId",
+				"type": "uint256"
+			}
+		],
+		"name": "Transfer",
+		"type": "event"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "address",
+				"name": "_from",
+				"type": "address"
+			},
+			{
+				"internalType": "address",
+				"name": "_to",
+				"type": "address"
+			},
+			{
+				"internalType": "uint256",
+				"name": "_tokenId",
+				"type": "uint256"
+			}
+		],
+		"name": "transferFrom",
+		"outputs": [],
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "_tokenId",
+				"type": "uint256"
+			}
+		],
+		"name": "ownerOf",
+		"outputs": [
+			{
+				"internalType": "address",
+				"name": "",
+				"type": "address"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	},
+	{
+		"inputs": [
+			{
+				"internalType": "uint256",
+				"name": "_tokenId",
+				"type": "uint256"
+			}
+		],
+		"name": "tokenURI",
+		"outputs": [
+			{
+				"internalType": "string",
+				"name": "",
+				"type": "string"
+			}
+		],
+		"stateMutability": "view",
+		"type": "function"
+	}
+];
+
+const contract = new web3.eth.Contract(contractABI, contractAddress);
+
+let lastBlockConsumed = 0;  // Initialize with the first block you want to start from
+
+async function pollForEvents() {
+    try {
+        const latestBlock = await web3.eth.getBlockNumber();
+
+        if (latestBlock > lastBlockConsumed) {
+            console.log(`Consuming blocks from ${lastBlockConsumed + BigInt(1)} to ${latestBlock}`);
+
+            const events = await contract.getPastEvents('allEvents', {
+                fromBlock: lastBlockConsumed + BigInt(1),
+                toBlock: 'latest'
+            });
+
+            for (let event of events) {
+                console.log("New Event: ", event);
+            }
+
+            // Update the last block consumed
+            lastBlockConsumed = latestBlock;
+        } else {
+            console.log("No new blocks since last check.");
+        }
+
+    } catch (error) {
+        console.error(`Error fetching events: ${error}`);
+    }
+
+    // Poll every 10 seconds
+    setTimeout(pollForEvents, 10000);
+}
+
+// Initialize with the latest block number
+web3.eth.getBlockNumber().then(blockNumber => {
+    lastBlockConsumed = blockNumber-BigInt(1);
+    pollForEvents();  // Start the polling
+});
+
+