Getting Started

Task

The mobile software testing team has 10 mobile phones that it needs to share for testing purposes.

• Samsung Galaxy S9
• 2x Samsung Galaxy S8
• Motorola Nexus 6
• Oneplus 9
• Apple iPhone 13
• Apple iPhone 12
• Apple iPhone 11
• iPhone X
• Nokia 3310

Please create a service that allows a phone to be booked / returned.

The following information should also be available for each phone.

• Availability (Yes / No)
• When it was booked
• Who booked the phone

Please send a notification to a message broker of your choice when a phone is either booked or returned.

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Proposed Solution

The task doesn't distinguish between book of the mobile to test and collection of the same, hence the implementation considers the \book verb as the action to collect the mobile by the requestor testing it, if the mobile is available. The mobile is booked until the due time.

The \return action makes the mobile available to be booked again if who returns it is the same who booked it.

The \list action returns the list of mobile devices as

• AVAILABLE if not booked/collected by anyone,
• IN USE if a requestor collected it, reporting when the book was made and return isdue.
• DUE if the requestor should have returned the mobile because now is after due.

Time properties as 'book made' and 'return due' are expressed as ISO 8601 local date-time strings.

The software is a Kotlin + Gradle project developed with JetBrain IDEA.

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Run

Kafka

Kafka must be available, if not follow the Apache Kafka Quickstart guide to install it locally.

Create the topics book and return where events are produced.

• bin/kafka-topics.sh --create --topic book --bootstrap-server localhost:9092
• bin/kafka-topics.sh --create --topic return --bootstrap-server localhost:9092

Run two Kafka Consumer clients, one for each topic, in two different shells.

• bin/kafka-console-consumer.sh --topic book --bootstrap-server localhost:9092
• bin/kafka-console-consumer.sh --topic return --bootstrap-server localhost:9092

Spring Application Server

The Kafka Broker must be up and running, by default at localhost:9092, before the application server runs.

The labels for the mobile devices are loaded as comma separated string elements by the mobiles key in the application.properties file.

• Open a shell in the directory where the woftware was downloaded.
• Build the application server with ./gradlew bootJar.
• Start the application server with java -jar build/libs/btcc-0.0.1-SNAPSHOT.jar
• Visit http://localhost:8080/swagger-ui/index.html how to use API end-points.
• Stop the application server pressing [CTRL+C].

Test

At least seven mobiles must be defined to allow ControllerTest to run tests in parallel and prove concurrent requests are handled correctly.

The directory src/test/kotlin/com/github/lucanicoladebiasi/btc has the test code covering the required behavior.

The test code embeds an application server to test REST-API end-point and an in-memory Kafka using the port 9093 to test messaging functionalities.

Run ./gradlew test to execute unit/integration tests.

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Reference Documentation

For further reference, please consider the following sections:

• Official Gradle documentation
• Spring Boot Gradle Plugin Reference Guide
• Create an OCI image
• Spring Web
• Spring for Apache Kafka
• Spring Boot DevTools

Guides

The following guides illustrate how to use some features concretely:

• Building a RESTful Web Service
• Serving Web Content with Spring MVC
• Building REST services with Spring

Additional Links

These additional references should also help you:

• Gradle Build Scans – insights for your project's build