ContractConsumer

A Brief overview about contract testing

Contract testing, is a testing carried out between two parties (Producer & Consumer). It has more focus on any changes from producer side, which should not cause failure on consumer side. It is NEITHER "Functional Testing", It is NOR "API Testing"

A general example of producer and consumer.

• A Inventory service which produce data for order service
• Order service which consume data from inventory service and create order based on that

Another example (This is example, came to mind and created services for that :) :

• A Tweet/comment API generally produce data about various topic.
• Entertainment service (imdb kind of) which basically uses comments and tweets and show it.

Produce side

• Tweet/Comment service produce data in json format (GET- localhost:8181/tweet/) [ { "userID": "1", "userName": "@Austin174", "tweetDescription": "#GameOfThrones:Why is it that when one man builds a wall, the next man immediately needs to know what's on the other side?" }, { "userID": "2", "userName": "@Thanh157", "tweetDescription": "#Friends:Raspberries? Good. Ladyfingers? Good. Beef? GOOD!" } ]
• To invoke producer service mvn clean spring-boot:run Note: Default it runs on "8181", you can changed it by providing from command line.

Consumer Side

• Entertainment service create shows belong to various categories. (POST- localhost:8081/showlocalhost:8081/show) { "showID":"3", "categoryName":"Non-Fictions", "showName":"Friends" }
• Fetch all created shows (GET- localhost:8081/show)
• It fetches data from tweet services, and showed filtered tweet in th form of Posts (GET- localhost:8081/posts/{showID })
• To Invoke consumer service mvn clean spring-boot:run

Testing side of Produce and Consumer sides: Consumer Side

• Invoke mvn clean test, It will run all tests (UT/IT/Contract tests) at consumer side.
• Pact file will be stored in '/target/pact'
• Generated pact file to be shared with Publisher (Upload shared location github/s3) or use cool way of it doing it using pact-broker (For further info Please refer [https://github.com/DiUS/pact_broker-docker]).
• To publish document on pact broker mvn pact:publish

Publisher Side

• Invoke mvn clean test, It will run all tests (UT/IT) at producer side.
• To invoke contract tests to producer side mvn pact:verify (Provided you share location either pactFile/pactUrl in maven-producer-plugin).

Further improvements

• Setting up webhooks to pact-broker, so it will shoot contract tests seamlessly between producer and consumer.

More about contact testing:

• [https://docs.pact.io/][]:
• [https://github.com/DiUS/pact-jvm/tree/master/consumer][]:
• [https://github.com/DiUS/pact-jvm/tree/master/provider][]:
• [https://github.com/thombergs/code-examples/tree/master/pact][]:
• [https://github.com/bitweft/consumer-driven-contract-testing][]: