how to unit test promise that modifies a variable that gets sent to a 3rd party in typescript

Question

I am writing my first set of unit tests for typescript code and having hard time figuring our how to test processRecord method since it doesn't return the array that contains key logic output.

 export const processRecord = async (event, context: AppContext) => {
  if (!event.Records) {
    return false;
  }

  const promises = event.Records.map(async (record: DynamoDBRecord) => {
    try {
      if (!record.dynamodb) {
        return false;
      }

      let newInsuranceNamesList: string[] = [];
      
      ...
      // some logic to update newInsuranceNamesList
      ...

      await sendTo3rdParty(newInsuranceNamesList);
    } catch (err) {
      console.error(err);
    }
  });

  return Promise.all(promises);
};

Checking when event.Records or record.dynamodb doesn't exist is easy because it returns false . But the only real way for me to test processRecord is by checking contents of newInsuranceNamesList array. How can I achieve it in unit test?

Answer 1

figured it out, simple answer - refactor and pull the logic that determines newInsuranceNamesList into its own method and unit test it