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Diffstat (limited to 'src/contract_wrappers/exchange_wrapper.ts')
| -rw-r--r-- | src/contract_wrappers/exchange_wrapper.ts | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts index 0eb600ff6..b2e48b36e 100644 --- a/src/contract_wrappers/exchange_wrapper.ts +++ b/src/contract_wrappers/exchange_wrapper.ts @@ -630,6 +630,7 @@ export class ExchangeWrapper extends ContractWrapper { callback: EventCallback): Promise<string> { assert.doesBelongToStringEnum('eventName', eventName, ExchangeEvents); assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema); + assert.isFunction('callback', callback); const exchangeContractAddress = await this.getContractAddressAsync(); const subscriptionToken = this._subscribe( exchangeContractAddress, eventName, indexFilterValues, artifacts.ExchangeArtifact.abi, callback, |