Kacper Urbaniec | SWE | 11.11.2022

Assignment 3: Dependencies

🏗️ Architecture

• provider.customer | CustomerService

  Spring Boot service available @ http://localhost:8080
  Provides a list of customers via a REST API. The customer has the typical information like name, address, date of birth, email address, status, and more. Besides the basic information, the customer has a list of financial products. Every product has a name, balance, product code, and interest rate, among others.

• consumer.info | InfoService

  Spring Boot service available @ http://localhost:8090
  Provides a modified list of customer via REST API. Returns a list of all customers with name, email, and status.

• consumer.aggregator | AggregatorService

  Node service available @ http://localhost:9000
  Provides a modified list of customer via REST API. Returns a list of all customers with names and an aggregated balance (sum of all product balances).

🤝 Test & Verify Pacts

1. Run tests & generate pact for InfoService consumer

   # On Unix: chmod +x ./consumer.info/gradlew
   ./consumer.info/gradlew -p "consumer.info" test 

2. Run tests & generate pact for AggregatorService consumer

   npm --prefix ./consumer.aggregator/ install
   npm --prefix ./consumer.aggregator/ run test 

3. Verfiy pacts for CustomerService provider

   # On Unix: chmod +x ./provider.customer/gradlew
   ./provider.customer/gradlew -p "provider.customer" test 

For example, if one were to remove the balance field from the API CustomerService, the contract check would fail and output the following error messages.

Pact & other consumer-driven testing frameworks help detect breaking service modifications to prevent such client defects.

🚀 Run

1. CustomerService

   ./provider.customer/gradlew -p "provider.customer" bootRun 

   API

   • /customers - Query all customers

     curl http://localhost:8080/customers

   • /customer/{customer-email} - Query specific customer

     curl http://localhost:8080/customer/customer.c@gmail.com

2. InfoService

   Requires running CustomerService.

   ./consumer.info/gradlew -p "consumer.info" bootRun 

   API

   • /customers - Query all customer info

     curl http://localhost:8090/customers

3. AggregatorService

   Requires running CustomerService.

   npm --prefix ./consumer.aggregator/ run build 
   npm --prefix ./consumer.aggregator/ run start 

   API

   • /customers - Query all customers with aggregated balances

     curl http://localhost:9000/customers

Additionally, a postman collection can be found in the test.postman folder to manually interact with the services.

Acknowledgments

• https://docs.pact.io/implementation_guides/javascript/readme
• https://github.com/pact-foundation/pact-js
• https://github.com/pact-foundation/pact-workshop-js
• https://docs.pact.io/implementation_guides/jvm
• https://github.com/pact-foundation/pact-workshop-jvm-spring