@aws-cdk/assert

Testing utilities and assertions for CDK libraries

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

0.8.2 - 2018-08-15

Features

• @aws-cdk/cdk: Tokens can now be transparently embedded into strings and encoded into JSON without losing their semantics. This makes it possible to treat late-bound (deploy-time) values as if they were regular strings ([@rix0rrr] in #518).
• @aws-cdk/aws-s3: add support for bucket notifications to Lambda, SNS, and SQS targets ([@eladb] in #201, #560, #561, #564)
• @aws-cdk/cdk: non-alphanumeric characters can now be used as construct identifiers ([@eladb] in #556)
• @aws-cdk/aws-iam: add support for maxSessionDuration for Roles ([@eladb] in #545).

Changes

• @aws-cdk/aws-lambda (BREAKING): most classes renamed to be shorter and more in line with official service naming (Lambda renamed to Function or ommitted) ([@eladb] in #550)
• @aws-cdk/aws-codepipeline (BREAKING): move all CodePipeline actions from @aws-cdk/aws-xxx-codepipeline packages into the regular @aws-cdk/aws-xxx service packages ([@skinny85] in #459).
• @aws-cdk/aws-custom-resources (BREAKING): package was removed, and the Custom Resource construct added to the @aws-cdk/aws-cloudformation package ([@rix0rrr] in #513)

Fixes

• @aws-cdk/aws-lambda: Lambdas that are triggered by CloudWatch Events now show up in the console, and can only be triggered the indicated Event Rule. BREAKING for middleware writers (as this introduces an API change), but transparent to regular consumers ([@eladb] in #558)
• @aws-cdk/aws-codecommit: fix a bug where pollForSourceChanges could not be set to false ([@maciejwalkowiak] in #534)
• aws-cdk: don't fail if the ~/.aws/credentials file is missing ([@RomainMuller] in #541)
• @aws-cdk/aws-cloudformation: fix a bug in the CodePipeline actions to correctly support TemplateConfiguration ([@mindstorms6] in #571).
• @aws-cdk/aws-cloudformation: fix a bug in the CodePipeline actions to correctly support ParameterOverrides ([@mindstorms6] in #574).

Known Issues

• cdk init will try to init a git repository and fail if no global user.name and user.email have been configured.