Fixes waitForBlock logic to not stop searching if the blockchain is a…

…t least advancing

lib/rsk-utils.js

@@ -35,27 +35,40 @@ const waitForSync = async (rskTransactionHelpers) => {
 };
 
 /**
- * 
- * @param {Web3} rskClient web3 client to make calls to the rsk network
- * @param {Number} blockNumber block to wait for
- * @param {Number} waitTime defaults to 200 milliseconds. Time to wait before checking for the block on every iteration
- * @param {Number} maxAttempts defaults to 6000 milliseconds. Attempts to try to get the indicated block number
- * @returns {Promise<Number>} the latest block number that we were waiting for
+ * Wait for the rsk blockchain to advance to the specified block number, attempting to find a new block `maxAttempts` times, checking every `waitTime` milliseconds.
+ * If the blockchain doesn't advance after `maxAttempts` attempts, it will consider the blockchain as stuck and it will throw an error.
+ * It will reset the attempts counter every time the blockchain advances as least 1 block.
+ * It will potentially try to find new blocks `maxAttempts` times for every block.
+ * If the blockchain is at least advancing, we know that some time in the future the `blockNumber` will be reached, so no need to stop trying to find it.
+ * @param {Web3} rskClient web3 client to make calls to the rsk network.
+ * @param {Number} blockNumber min block height to wait for.
+ * @param {Number} waitTime defaults to 200 milliseconds. Time to wait before checking for the block on every iteration.
+ * @param {Number} maxAttempts defaults to 80 attempts by block.
+ * @returns {Promise<Number>} the latest block number the same or greater than `blockNumber`.
  */
-const waitForBlock = (rskClient, blockNumber, waitTime = 200, maxAttempts = 600) => {
+const waitForBlock = (rskClient, blockNumber, waitTime = 200, maxAttempts = 80) => {
   return new Promise((resolve, reject) => {
-    let attempts = 0;
+    let attempts = 1;
+    let latestBlockNumber = -1;
     const checkBlockNumber = () => {
-      rskClient.eth.getBlockNumber().then(latestBlockNumber => {
-        if (latestBlockNumber >= blockNumber) {
-          return resolve(latestBlockNumber);
+      rskClient.eth.getBlockNumber().then(newLatestBlockNumber => {
+        const expectedMinBlockHeightReached = newLatestBlockNumber >= blockNumber;
+        if (expectedMinBlockHeightReached) {
+          return resolve(newLatestBlockNumber);
+        }
+        const isAdvancing = newLatestBlockNumber > latestBlockNumber;
+        if(isAdvancing) {
+          latestBlockNumber = newLatestBlockNumber;
+          attempts = 0;
+        } else {
+          if (attempts++ === maxAttempts) {
+            const message = `Blockchain not advancing after attempting to find a new block ${maxAttempts} times checking every ${waitTime} milliseconds. Couldn't reach block number ${blockNumber}. Last block number seen was: ${newLatestBlockNumber}`;
+            return reject(new Error(message));
+          }
         }
-        if (attempts++ === maxAttempts) {
-          return reject(new Error(`Block number ${blockNumber} never reached, last seen was ${latestBlockNumber}`));
-        };
         setTimeout(checkBlockNumber, waitTime);
-      }).catch((ex) => {
-        reject("waitForBlock " + ex.stack);
+      }).catch(error => {
+        reject('[waitForBlock] ' + error.stack);
       });
     };
     checkBlockNumber();