jest-aws-client-mock

Jest mock for AWS SDK v3 Clients

Installation

1// with npm
2npm install -D jest-aws-client-mock
3
4// with yarn
5yarn add -D jest-aws-client-mock

How to use

1import { PublishCommand, SNSClient } from '@aws-sdk/client-sns';
2import { mockClient } from 'jest-aws-client-mock';
3
4const snsMock = mockClient(SNSClient);
5
6beforeEach(() => {
7  snsMock.mockReset();
8});
9
10test('mock sns client', async () => {
11  expect.assertions(3);
12
13  snsMock.mockResolvedValue({
14      MessageId: '123',
15  });
16
17  const snsClient = new SNSClient({});
18
19  const command = new PublishCommand({
20      Message: 'message',
21      TopicArn: 'arn:aws:sns:us-east-1:111111111111:TestTopic',
22  });
23
24  const result = await snsClient.send(command);
25
26  expect(snsMock).toHaveBeenCalledTimes(1);
27  expect(snsMock).toHaveBeenCalledWith(command);
28  expect(result).toEqual({ MessageId: '123' })
29});

DynamoDBDocumentClient

1import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
2import { DynamoDBDocumentClient, GetCommand, GetCommandOutput } from '@aws-sdk/lib-dynamodb';
3import { mockClient } from 'jest-aws-client-mock';
4
5const ddbMock = mockClient(DynamoDBDocumentClient);
6
7beforeEach(() => {
8  ddbMock.mockReset();
9});
10
11test('dynamodbDocumentClient', async () => {
12  expect.assertions(3);
13
14  const output: Partial<GetCommandOutput> = {
15    Item: {
16      Id: '4711',
17    },
18  };
19
20  ddbMock.mockResolvedValue(output);
21
22  const command = new GetCommand({
23    TableName: 'tableName',
24    Key: {
25      Id: '4711',
26    },
27  });
28
29  const dynamodbClient = new DynamoDBClient({});
30
31  const ddb = DynamoDBDocumentClient.from(dynamodbClient);
32
33  const result = await ddb.send(command);
34
35  expect(ddbMock).toHaveBeenCalledTimes(1);
36  expect(ddbMock).toHaveBeenCalledWith(command);
37  expect(result).toEqual(output);
38});

Asymetric matchers

1import { PublishCommand, SNSClient } from '@aws-sdk/client-sns';
2import { mockClient } from 'jest-aws-client-mock';
3
4const snsMock = mockClient(SNSClient);
5
6beforeEach(() => {
7  snsMock.mockReset();
8});
9
10test('mock - asymetric matcher', async () => {
11  expect.assertions(1);
12
13  const snsClient = new SNSClient({});
14
15  const command = new PublishCommand({
16      Message: 'random',
17      TopicArn: 'arn:aws:sns:us-east-1:111111111111:TestTopic',
18  });
19
20  await snsClient.send(command);
21
22  expect(snsMock).toHaveBeenCalledWith(
23    expect.objectContaining({
24      input: {
25        TopicArn: 'arn:aws:sns:us-east-1:111111111111:TestTopic',
26        Message: expect.any(String),
27      },
28    }),
29  );
30});

License

MIT