pact-broker-tests

Sample project showing how to execute Pact tests. Here you can find 2 Java projects and 1 broker:

• broker: keeps the the pacts and it's versions to be used between the tests
• consumer: the project that uses the provider api and is responsible by the pacts publication
• provider: the project that verifies if the pacts match with it's own api

Documentation

• https://docs.pact.io/pact_broker

• Following is the basic Pact flow to verify contracts. The broker comes to centralize pacts and keep them simpler to share

  

Tools

• java: 17.0.1
• docker: 20.10.7
• docker-compose: 1.29.2
• pact-broker cli: 1.50.0
• gradle: 7.2
• wiremock: 2.31.0 (lives inside the tests)
• pact-broker: 2.89.1.0 (lives inside docker)
• postgres: 14.0 (lives inside docker)

How to run

1. First of all, export the following variables to use during the tests:

   $ export BROKER_URL="http://localhost:9292" && \
     export CONSUMER_VERSION="1.0.0" && \
     export PROVIDER_VERSION="1.0.0" && \
     export TAG="dev"
   

2. Start the Pact Broker. If this command executes successfully, the broker will be exposed at http://localhost:9292:

   $ docker-compose up
   

3. Execute the consumer tests. These tests are going to generate the pact in the ./consumer/build/pacts/ folder:

   $ consumer/./gradlew -p ./consumer :test --tests '*Pact*'
   

4. Publish the pacts to the broker:

   $ pact-broker publish "./consumer/build/pacts" \
       --consumer-app-version $CONSUMER_VERSION \
       --broker-base-url $BROKER_URL \
       --tag $TAG
   

5. Execute the provider tests. These tests are going to verify if the interactions between consumer and provider are correct, using an http mock to check the results against the Pact Broker:

   $ PACT_PROVIDER_VERSION=$PROVIDER_VERSION \
       provider/./gradlew \
       -p ./provider \
       :test --tests '*Pact*'
   

6. Create a tag for the provider to keep the can-i-deploy command simpler:

   $ pact-broker create-version-tag \
       --pacticipant "users-provider" \
       --version $PROVIDER_VERSION \
       --tag $TAG \
       --broker-base-url $BROKER_URL
   

7. Check if the provider can be deployed:

   $ pact-broker can-i-deploy \
       --pacticipant "users-provider" \
       --to $TAG \
       --version $PROVIDER_VERSION \
       --broker-base-url $BROKER_URL
   
   Computer says yes \o/
   
   CONSUMER       | C.VERSION | PROVIDER       | P.VERSION | SUCCESS? | RESULT#
   ---------------|-----------|----------------|-----------|----------|--------
   users-consumer | 1.0.0     | users-provider | 1.0.0     | true     | 1
   
   VERIFICATION RESULTS
   --------------------
   1. http://localhost:9292/pacts/provider/users-provider/consumer/users-consumer/pact-version/c6c22a2291ec062638f45a405ecf58c0cbec05bf/metadata/Y3ZuPTEuMC41/verification-results/216 (success)
   
   All required verification results are published and successful
   

8. Check if the consumer can be deployed:

   $ pact-broker can-i-deploy \
       --pacticipant "users-consumer" \
       --to $TAG \
       --version $CONSUMER_VERSION \
       --broker-base-url $BROKER_URL
   
   Computer says yes \o/
   
   CONSUMER       | C.VERSION | PROVIDER       | P.VERSION | SUCCESS? | RESULT#
   ---------------|-----------|----------------|-----------|----------|--------
   users-consumer | 1.0.0     | users-provider | 1.0.0     | true     | 1
   
   VERIFICATION RESULTS
   --------------------
   1. http://localhost:9292/pacts/provider/users-provider/consumer/users-consumer/pact-version/c6c22a2291ec062638f45a405ecf58c0cbec05bf/metadata/Y3ZuPTEuMC4w/verification-results/215 (success)
   
   All required verification results are published and successful
   

How to test a failure

1. After executing the previous steps, go to the provider test UsersPactTest.java and change the JSON body to have have the ID = 2

2. Execute the tests again. They must fail:

   $ PACT_PROVIDER_VERSION=$PROVIDER_VERSION \
       provider/./gradlew \
       -p ./provider \
       :test --tests '*Pact*'
       
   java.lang.AssertionError: Pact between users-consumer (1.0.0) and users-provider - Upon Should return all available properties in response body. 
   Failures:
   
   1) Verifying a pact between users-consumer and users-provider - Should return all available properties in response body. has a matching body
   
       1.1) body: $.id Expected '1' (String) but received '2' (String)
   

3. If you try to check if the provider deployment can be executed:

   $ pact-broker can-i-deploy \
      --pacticipant "users-provider" \
      --to $TAG \
      --version $PROVIDER_VERSION \
      --broker-base-url $BROKER_URL
   
    Computer says no ¯_(ツ)_/¯
   
    CONSUMER       | C.VERSION | PROVIDER       | P.VERSION | SUCCESS? | RESULT#
    ---------------|-----------|----------------|-----------|----------|--------
    users-consumer | 1.0.0     | users-provider | 1.0.0     | false    | 1
   
    VERIFICATION RESULTS
    --------------------
    1. http://localhost:9292/pacts/provider/users-provider/consumer/users-consumer/pact-version/47c8ebf1805daafccc2f7eae273306bfd3d941bf/metadata/Y3ZuPTEuMC4w/verification-results/201 (failure)
   
    The verification for the pact between the latest version of users-consumer with tag dev (1.0.0) and version 1.0.0 of users-provider failed
   

4. If you try to check if the consumer deployment can be executed:

   $ pact-broker can-i-deploy \
      --pacticipant "users-consumer" \
      --to $TAG \
      --version $CONSUMER_VERSION \
      --broker-base-url $BROKER_URL
   
    Computer says no ¯_(ツ)_/¯
   
    CONSUMER       | C.VERSION | PROVIDER       | P.VERSION | SUCCESS? | RESULT#
    ---------------|-----------|----------------|-----------|----------|--------
    users-consumer | 1.0.0     | users-provider | 1.0.0     | false    | 1
   
    VERIFICATION RESULTS
    --------------------
    1. http://localhost:9292/pacts/provider/users-provider/consumer/users-consumer/pact-version/47c8ebf1805daafccc2f7eae273306bfd3d941bf/metadata/Y3ZuPTEuMC4w/verification-results/201 (failure)
   
    The verification for the pact between version 1.0.0 of users-consumer and the latest version of users-provider with tag dev (1.0.0) failed