@aws-cdk/assert

Testing utilities and assertions for CDK libraries

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This is a developer preview (public beta) module. Releases might lack important features and might have future breaking changes.

This API is still under active development and subject to non-backward compatible changes or removal in any future version. Use of the API is not recommended in production environments. Experimental APIs are not subject to the Semantic Versioning model.

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This library contains helpers for writing unit tests and integration tests for CDK libraries

Unit tests

Write your unit tests like this:

const stack = new Stack();

new MyConstruct(stack, 'MyConstruct', {
    ...
});

expect(stack).to(someExpectation(...));

Here are the expectations you can use:

Verify (parts of) a template

Check that the synthesized stack template looks like the given template, or is a superset of it. These functions match logical IDs and all properties of a resource.

matchTemplate(template, matchStyle)
exactlyMatchTemplate(template)
beASupersetOfTemplate(template)

Example:

expect(stack).to(beASupersetOfTemplate({
    Resources: {
        HostedZone674DD2B7: {
            Type: "AWS::Route53::HostedZone",
            Properties: {
                Name: "test.private.",
                VPCs: [{
                    VPCId: { Ref: 'VPC06C5F037' },
                    VPCRegion: { Ref: 'AWS::Region' }
                }]
            }
        }
    }
}));

Check existence of a resource

If you only care that a resource of a particular type exists (regardless of its logical identifier), and that some of its properties are set to specific values:

haveResource(type, subsetOfProperties)

Example:

expect(stack).to(haveResource('AWS::CertificateManager::Certificate', {
    DomainName: 'test.example.com'
    // Note: some properties omitted here
}));

Integration tests

Integration tests are modeled as CDK apps that are deployed by the developers. If deployment succeeds, the synthesized template is saved in a local file and "locked". During build, the test app is only synthesized and compared against the checked-in file to protect against regressions.

Setup

Create any number of files called integ.*.ts in your test directory. These should be CDK apps containing a single stack.

Add the following to your package.json':

{
    scripts: {
        "test": ".... && cdk-integ-assert",
        "integ": "cdk-integ"
    },
    ...
    devDependencies: {
        "@aws-cdk/assert": "*",
        "aws-cdk": "*"
    }
}

This installs two tools into your scripts:

• When npm test is executed (during build), the cdk-integ-assert tool is invoked. This tool will only synthesize the integration test stacks and compare them to the .expected files. If the files differ (or do not exist), the test will fail.
• When npm run integ is executed (manually by the developer), the cdk-integ tool is invoked. This tool will actually attempt to deploy the integration test stacks into the default environment. If it succeeds, the .expected file will be updated to include the latest synthesized stack.

The usage of cdk-integ is:

cdk-integ [--no-clean] [filters...]

# or

npm run integ -- [--no-clean] [filters...]

• If --no-clean is specified, the integration test stacks will not be cleaned up. This can be used to perform manual validation on the stacks.
• If filters are specified, each test name is evaluated against each filter. If the name matches any of the filters, the test is included. Otherwise it is skipped.

Changelog

1.0.0 (2019-07-09)

General Availability of the AWS Cloud Development Kit!! 🎉🎉🥂🥂🍾🍾

We are excited to announce the 1.0.0 release of the AWS CDK – including GA support for TypeScript, JavaScript, and Python!

We want to thank all of our early customers, and the hundreds of contributors, for all the help and support in making this release a reality. Thank you for the patience to deal with the many, many breaking changes that happened along the way. This product would not be what it is today if it weren't for all the feedback, diligent issue reporting (bugs, missing features, unclear documentation, etc.), and code contributions from the community.

Special thanks go out to a few of our most prolific contributors who went above and beyond to help improve the CDK:

• Mike Cowgill
• Jonathan Goldwasser
• Breland Miley
• Piradeep Kandasamy
• Hsing-Hui Hsu
• Simon-Pierre Gingras
• Jungseok Lee
• Clare Liguori
• Yenlin Chen
• Lee Packham

1.0.0 is a huge milestone for us, but it's still only the beginning! We are excited to continue evolving the CDK, to introduce support for new languages and capabilities, and to continue working closely with the open-source community.

Bug Fixes

• cli: output message when successfully synthesizing multiple stacks (#3259) (0c30f12)
• python: Make sure stack name in the init template does not contain illegal characters (#3261) (7d22b2c)