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Verifying Contracts

In contract definition, we produced a contract made of expected request / response pairs, and confirmed that the consumer works correctly if those expectations are met by the provider.

Contract verification (described in this section) confirms that the provider actually meets those expectations. The output of contract verification is the information that this version of the provider is compatible with the consumer(s) which generated the contract.

What does verification mean?

Because contract verification checks that a provider meets the expectations of a given contract, you can think of contract verification as asking "can these two services communicate with each other?"

Because contracts often don't change between versions, it's normal for multiple versions of the consumer to be covered by one contract. You don't need to de-duplicate contracts - ContractCase will hash them for you automatically.

Multiple verifications.​

Even if you have only one consumer, It's common to verify more than one contract at once - usually you want the contracts currently deployed in each environment, and the last N versions (to enable safe rollbacks). For convenience, ContractCase will verify all available contracts for the configured provider during a single verifyContract call.

If you have multiple consumers, you would run verifications for all consumers of the current provider too. For convenience, you can leave out the consumerName during a verifyContract call, and ContractCase will verify all contracts for this provider.

Verifying a contract​

Depending on what is in your contract, you may need to set triggers or state handlers.

If you need to set these, and don't, then ContractCase will fail with a configuration error.

verifyContract(
  {
    providerName: YOUR_SERVICE_NAME,
    contractDir: './temp-contracts', // The downloader can currently only download contracts to `temp-contracts`
  },
  (verifier) => {
    // perform any setup
    // Start your service here (if necessary)

    verifier.runVerification(/* any additional config eg triggers or state handlers goes in here */);
  },
);
  • By default, verification results are uploaded to a broker if the broker access tokens and baseUrl are set and the run is in CI. Set the option publish: true or publish: false to override this
  • By default, verification failures will not throw errors. This can be overridden with throwOnFail: true in the options.
  • You will need to add deployment checks before you get the deployment safety