@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

0.21.0 (2018-12-20)

Bug Fixes

• aws-cloudformation: change the type of Role in CodePipeline Actions to IRole. (#1364) (3d07e48), closes #1361
• codebuild: Rename includeBuildID property of S3BucketBuildArtifacts (#1354) (84eb7ad), closes #1347
• toolkit: scrutiny dialog should fail with no tty (#1382) (478a714), closes #1380

Features

• aws-codebuild: change the API of GitHub and BitBucket Sources. (#1345) (9cebf0d)
• add "engines.node" key to all packages (#1358) (b595cf0), closes #1337
• deprecate "cloudformation" namespace in favor of "CfnXxx" (#1311) (d20938c), closes #878 awslabs/jsii#283 awslabs/jsii#270
• update CloudFormation resources v2.18.0 (#1407) (0f80b56), closes #1409
• aws-codebuild: allow setting Webhook for GitHub Sources. (#1387) (d5cae61)
• aws-ec2: can now use PrefixList in ingress rules (#1360) (c3cfcd5)
• aws-iam: configure ExternalId for Role (#1359) (3d200c9), closes #235
• aws-lambda: Add python 3.7 runtime (#1379) (8c733ef)
• cdk: add the CodeDeployLambdaAlias Update Policy. (#1346) (d648b58), closes #1177
• core: convert "/" in construct id to "--" and disallow tokens (#1375) (011aac0), closes #1351 #1374
• iam: CompositePrincipal and allow multiple principal types (#1377) (b942ae5), closes #1201

BREAKING CHANGES TO EXPERIMENTAL FEATURES

• aws-cloudformation: this changes the type of the role property in CFN CodePipeline Actions from Role to IRole. This is needed to use imported Roles when creating Actions.
• aws-codebuild: this changes the API of CodeBuild's GitHub and BitBucket Sources to take an owner/repo pair instead of an entire cloneUrl, to make it consistent with the GitHubSourceAction in the CodePipeline package. Also adds handling the reportBuildStatus and insecureSsl Source properties.
• codebuild: the includeBuildID property of S3BucketBuildArtifacts was renamed to includeBuildId (note the lower-case trailing d).