Calculating TxID for all transactions in a block, then verify those TxIDs exist.

index.js

import algosdk from 'algosdk';

const token = 'a'.repeat(64);
const address = 'http://192.168.1.100';
const port = 8080;

const client = new algosdk.Algodv2(token, address, port);

// Recursively remove all null values
function removeNulls(obj) {
  for (let key in obj) {
    if (obj[key] === null) {
      delete obj[key];
    } else if (typeof obj[key] === 'object') {
      removeNulls(obj[key]);
    }
  }
}

(async() => {
  let status = await client.status().do();

  while (true) {
    let last_round = status['last-round'];
    console.log(last_round);

    const round = await client.block(last_round).do();
    //console.log(round);

    const block = round['block']
    //console.log(block);

    const txns = block['txns'];
    //console.log(txns);

    for (const t in txns) {
      const tx = txns[t];
      const txn = txns[t]['txn'];

      // Skip StateProofs
      if (txn['type'] == 'stpf')
        continue

      // Remove nulls (mainly for appl args)
      removeNulls(txn);

      let gh = block.gh;
      let gen = block.gen;
      // Unset gen if `hgi` isn't set
      if (!tx['hgi'])
        gen = null;

      // Construct Transaction
      const transaction = algosdk.Transaction.from_obj_for_encoding({...txn, gh, gen});
      const txid = transaction.txID();

      // Validate the TxID exists against the node
      // !! Don't run on a public endpoint, you'll probably get rate limited !!
      const valid = await client.pendingTransactionInformation(txid).do();
      if (valid)
        console.log(txid + "\t Valid");
    }

    // Wait for next round
    status = await client.statusAfterBlock(last_round).do();
    last_round = status['last-round'];
  }
})();