TypeScript Event Bindings

This is a demo of how you can create typesafe bindings for contract events.

You can refer directly to the generated.ts file in this repo to see the output for the example contract after deployment, or you can run the process yourself as follows, once you've funded an account (see the CLI manual for help on that):

npm i
stellar contract build
stellar contract deploy --wasm <path from above> --network testnet --source-account <...>
# remember the contract id
# it's deployed as CBMWOANWBHW5BYJ6GNACCMK2CQVTE6LUAP3XGIRIQK3NXWVOZLHXDSM3 today
npx tsx main.ts CBMWOANWBHW5BYJ6GNACCMK2CQVTE6LUAP3XGIRIQK3NXWVOZLHXDSM3
cat generated.ts

stellar contract invoke <...> -- emit
curl -X POST -H 'Content-Type: application/json' -d '
    { "jsonrpc": "2.0", "id": 1,
     "method": "getTransaction",
     "params": {
        "hash": "<sha from above invoke>"
    }}' https://soroban-testnet.stellar.org/ | jq .result.events.contractEventsXdr[0][0]

# load that base64 into the new `DefaultEvent` object and observe:

const b64 = "AAAAAAAAAAHISDHhxJ+JSBzDWDgWbWriOirUe4TsyFj1IhuBfaI+CwAAAAEAAAAAAAAAAwAAAA8AAAANZGVmYXVsdF9ldmVudAAAAAAAABIAAAAByEgx4cSfiUgcw1g4Fm1q4joq1HuE7MhY9SIbgX2iPgsAAAADAAAAAgAAABEAAAABAAAAAwAAAA8AAAADYW55AAAAAAQAAAAFAAAADwAAAAZiaWdudW0AAAAAAAp///////////////////0oAAAADwAAAAZuZXN0ZWQAAAAAABAAAAABAAAAAgAAABEAAAABAAAAAQAAAA4AAAAFaGVsbG8AAAAAAAAGAAAAAAAAABsAAAARAAAAAQAAAAEAAAAOAAAABWhlbGxvAAAAAAAABgAAAAAAAAAb";
const e = new DefaultEvent(xdr.ContractEvent.fromXDR(b64, "base64"));
console.info(e.nested);

$ npx tsx generated.ts
[ { hello: 27n }, { hello: 27n } ]