aws-sdk - dynamodb client + test

adapter-dynamodb.ts

import { DynamoDBClient, DynamoDBClientConfig } from '@aws-sdk/client-dynamodb'
import { DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb'

// @aws-sdk (v3) has keepAlive enabled by default
export const DynamoClient = new DynamoDBClient({});

const marshallOptions = {
  convertEmptyValues: false,
  removeUndefinedValues: false,
  convertClassInstanceToMap: false,
};

const unmarshallOptions = {
  wrapNumbers: false,
};

const translateConfig = { marshallOptions, unmarshallOptions };

export const DynamoDocument = DynamoDBDocumentClient.from(DynamoClient, translateConfig);

create-loan.spect.ts

import 'aws-sdk-client-mock-jest' // provides `toHaveReceivedCommandWith` assertion
import { mockClient } from 'aws-sdk-client-mock'

import { DynamoDocument } from './adapter-dynamodb'

// mock either your dynamo client instance or `DynamoClient` directly from @aws-sdk/client-dynamodb
const ddbMock = mockClient(DynamoDocument)


beforeEach(() => {
  ddbMock.reset()
}

it('expects PutCommand to be called', async () => {
  const payload = { amount: 4382490 }
  await createLoan(payload)

  await expect(ddbMock).toHaveReceivedCommandWith(PutCommand, {
    TableName: 'loans',
    Item: expect.objectContaining(payload)
  })
})

create-loan.ts

import { PutCommand } from '@aws-sdk/lib-dynamodb'
import { DynamoDocument } from './adapter-dynamodb'

export async function createLoan(payload): Promise<any> {
  await DynamoDocument.send(
    new PutCommand({
      TableName: 'loans',
      Item: payload,
    })
  )
  
  return payload
}