Add caching of startBlock

lib/etherscan.mjs

@@ -1,23 +1,53 @@
 import { RetryableError, wrapRetryable } from "./retryable.mjs";
 
+/**
+ * Cache startBlocks
+ * @type {Map<string, BigInt>}
+ */
+let startBlocks = new Map();
+
 export const getTokenTx = wrapRetryable(async function getTokenTx(etherscan, params) {
+    // Construct URL without startBlock
     const url = new URL(`https://api.${etherscan}/api`);
     url.searchParams.append("module", "account");
     url.searchParams.append("action", "tokentx");
     url.searchParams.append("page", "1");
     Object.entries(params).forEach(([key, value]) => url.searchParams.append(key.toLowerCase(), value));
     url.searchParams.append("sort", "desc");
+
+    // Calculate Cache key before appending startBlock
+    const key = url.toString();
+
+    // Append startBlock from cache if present
+    const startBlock = startBlocks.get(key);
+    if (startBlock) url.searchParams.append("startblock", startBlock.toString());
+
     let response;
     try {
         response = await fetch(url);
     } catch (error) {
         throw new RetryableError(`${etherscan} connection error`, true, error);
     }
     if (!response.ok)
-        throw new RetryableError(`${etherscan} got ${response.status}`, response.status >= 500);
+        throw new RetryableError(
+            `${etherscan} got ${response.status}`,
+            response.status >= 500,
+            url
+        );
     const text = await response.text();
     const json = JSON.parse(text);
     if (json.status !== "1")
-        throw new RetryableError(`${etherscan} error "${text}}"`, json.result === "Invalid API Key" || json.message === "No transactions found");
-    return json.result;
+        throw new RetryableError(
+            `${etherscan} error "${text}}"`,
+            json.result === "Invalid API Key" || json.message === "No transactions found",
+            url
+        );
+    const { result } = json;
+
+    // If transactions present cache last transaction start block
+    if (result.length !== 0) {
+        result.sort((a, b) => Number(BigInt(a.blockNumber) - BigInt(b.blockNumber)));
+        startBlocks.set(key, BigInt(result.at(-1).blockNumber) - 1n);
+    }
+    return result;
 });

lib/retryable.mjs

@@ -2,12 +2,12 @@ import { sleep } from "./utils.mjs";
 
 export class RetryableError extends Error {
     #canRetryOrRetryAfter;
-    originalError;
+    details;
 
-    constructor(message, canRetryOrRetryAfter, originalError) {
+    constructor(message, canRetryOrRetryAfter, details) {
         super(message);
         this.#canRetryOrRetryAfter = canRetryOrRetryAfter;
-        this.originalError = originalError;
+        this.details = details;
     }
 
     get retryAfter() {
@@ -29,7 +29,7 @@ async function callRetryable(fn, attempt = 0) {
     } catch (error) {
         if (error instanceof RetryableError && error.canRetry && attempt <= 10) {
             const retryAfter = error.retryAfter ?? (2 ** attempt) * 750;
-            console.warn(`${error.message}, retrying after ${retryAfter} ms`, error.originalError);
+            console.warn(`${error.message}, retrying after ${retryAfter} ms`, error.details);
             await sleep(retryAfter);
             return callRetryable(fn, attempt++);
         }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tokentx-notifier",
-  "version": "1.4.4",
+  "version": "1.4.5",
   "description": "A telegram bot that sends a message when new ERC20 transactions are detected",
   "keywords": ["telegram", "crypto", "ethereum", "erc20", "bot"],
   "homepage": "https://github.com/varanauskas/tokentx-notifier",