@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
}));

Check existence of an output

haveOutput assertion can be used to check that a stack contains specific output. Parameters to check against can be:

• outputName
• outputValue
• exportName

If outputValue is provided, at least one of outputName, exportName should be provided as well

Example

expect(synthStack).to(haveOutput({
  outputName: 'TestOutputName',
  exportName: 'TestOutputExportName',
  outputValue: {
    'Fn::GetAtt': [
      'TestResource',
      'Arn'
    ]
  }
}));

Changelog

1.21.1 (2020-01-16)

Bug Fixes

• ecr-assets: cannot build docker images outside the source tree (i.e. against a cdk.out directory) (#5836) (6bc8ecc), fixes (#5807)
• cli: cdk init fails if run under a directory where cdk.json exists, reverts (#5772) due to an issue which will be fixed in a subsequent version (#5836) (da9c626) , fixes (#5826)