Managing tasks to Kotlin

Transcript

1. Managing tasks
   to Kotlin
   Kentaro Takiguchi
   @rejasupotaro
   

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2. About me
   • Kentaro Takiguchi @ Cookpad
   • Visited Asian countries, US, Middle East, Europe,
   … => Settle down to a new life in UK
   

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4. My motivation of
   automation
   • This project is unique and challenging (= fun)
   • Product: Cultural difference, linguistic
   difference, …
   • Development: Remote team, different opinions
   and backgrounds, …
   • Many problems I want to solve => I want to make
   myself more productive
   

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5. A day of mine
   • Have coffee
   • Code review
   • Talk about technical issues
   • Talk about hiring
   • Lunch
   • Write code
   • Work on translation
   • Release
   • Monitor errors
   • Analyze logs
   • Create slides
   • Go to gym
   • Write a blog post
   

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6. How much time can you
   take only for coding?
   

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7. Make machines work
   instead of humans
   • Report lint warnings instead members review
   code carefully and leave comments on GitHub
   • Display test coverage on each PR to encourage
   members to write tests instead of saying “please
   add tests”
   • Download/Upload translation instead members
   open a translation tool and click some buttons
   

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8. Task manegement was
   chaos
   • Make, Rake, … Gradle?
   • How it’s managed depends on the project
   • How about your project?
   

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9. How to manage tasks
   • Rake > Gradle?
   • There are many gems such as Fastlane, GitHub,
   DeployGate, OneSky, Slack…
   • Gradle
   • We can (have to) choose from Java or Groovy
   • There are few plugins/libraries
   • But…
   

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11. It changed my mind
    • We have to choose from Java or Groovy
    • => Now Kotlin is a realistic option
    • There are few plugins/libraries
    • => Opportunity
    

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12. It’s a good time to
    learn Gradle tasks
    

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13. Gradle
    • Build automation system
    • Gradle uses a directed a cyclic graph (DAG) to
    determine the order of tasks
    • Stable release: 4.0
    • Gradle’s Build Cache is now production-ready
    which makes Gradle builds up to 100x faster
    than Maven
    

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14. 1. Build script (Groovy)
    2. buildSrc (JVM languages)
    3. Standalone project (JVM languages)
    How to define Gradle
    tasks
    

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15. Build script
    • Define tasks directly in the build.gradle
    • The task class is automatically compiled and
    included in the class path of the build script
    • The task class is not visible outside the build
    script
    

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16. Method 1-1
    // app/build.gradle

    task yourTaskName {

    doLast {
    // What you want to do

    }

    }
    

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17. Method 1-1
    // app/build.gradle

    task hello {

    doLast {
    println “Hello”

    }

    }
    ./gradlew hello => “Hello”
    

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18. Method 1-2
    // app/build.gradle
    task("hello") {

    doLast {

    println "Hello"

    }

    }
    

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19. Method 1-3
    // app/build.gradle
    tasks.create(name: “hello”) {

    doLast {

    println "hello"

    }

    }
    

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20. Method 1-4
    // app/build.gradle

    task hello(type: HelloTask)
    

    class HelloTask extends DefaultTask {

    @TaskAction

    def hello() {

    println “Hello”

    }

    }
    

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22. Many ways…
    • No need to remember everything but should
    unify how to define tasks in the same project
    • We have to write tasks in Groovy when we go
    with 1. Build script
    

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23. buildSrc project
    • Define the task class in `rootProject/buildSrc`
    • Gradle will take care of compiling and testing the
    task class and making it available on the class
    path of the build script
    

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24. buildSrc project
    1. Create buildSrc directory
    2. Add `build.gradle`
    3. Create `src/main/groovy/your/package/
    HelloTask.groovy`
    

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25. Method 2 (Groovy)
    // app/build.gradle
    task hello(type: HelloTask)
    // buildSrc/src/main/groovy/your/package/HelloTask.groovy

    class HelloTask extends DefaultTask {

    @TaskAction

    def hello() {

    println(“Hello”)

    }

    }
    

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26. Method 2 (Java)
    // app/build.gradle
    task hello(type: HelloTask)
    // buildSrc/src/main/java/your/package/HelloTask.java
    public class HelloTask extends DefaultTask {

    @TaskAction

    def hello() {

    System.out.println(“Hello”)

    }

    }
    

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27. Method 2 (Kotlin)
    // app/build.gradle
    task hello(type: HelloTask)
    // buildSrc/src/main/kotlin/your/package/HelloTask.kt
    open class HelloTask : DefaultTask() {

    @TaskAction

    fun hello() {

    println(“Hello”)

    }

    }
    

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28. Write tests for buildSrc
    class HelloTaskTest {

    @Test

    fun hello() {

    val project = ProjectBuilder.builder().build()

    val task = project.task("hello")

    assertTrue(task is HelloTask)

    }

    }
    

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29. Isn’t it better than 1. Build
    script?
    • We can write Kotlin
    • We can test
    • It’s still unavailable outside the project
    

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30. Standalone project
    = Gradle Plugin
    • This project produces and publishes a JAR
    which you can use in multiple builds and share
    with others
    • The JAR might bundle several related task
    classes into a single library
    

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31. How to write Gradle Plugin
    in Kotlin
    1. Create Java library project
    2. Apply “Convert Java File to Kotlin File”
    3. Add properties file
    4. Define Plugin
    5. Add tasks (We already known!)
    6. Add tests (We already known!)
    7. Publish
    

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32. 3. Add properties file
    

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33. 4. Define Plugin
    // plugin/src/main/kotlin/your/package/HelloPlugin.kt
    class YourPlugin : Plugin {

    override fun apply(project: Project) {

    with(project) {

    extensions.create(“yourExtension", YourExtension::class.java)

    tasks.create("yourTask1", YourTask1::class.java)

    tasks.create("yourTask2", YourTask2::class.java)

    tasks.create("yourTask3", YourTask3::class.java)

    }

    }

    }
    

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34. Create extension
    (if needed)
    // plugin/src/main/kotlin/your/package/HelloPlugin.kt
    class YourPlugin : Plugin {

    override fun apply(project: Project) {

    with(project) {

    extensions.create(“yourExtension", YourExtension::class.java)

    tasks.create("yourTask1", YourTask1::class.java)

    tasks.create("yourTask2", YourTask2::class.java)

    tasks.create("yourTask3", YourTask3::class.java)

    }

    }

    }
    

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35. Extension
    open class OneskyExtension {

    var apiKey: String = ""

    var apiSecret: String = ""

    var projectId: Int = 0

    var locales: Set = setOf()

    

    fun locales(locales: Array) {

    this.locales = locales.toSet()

    }

    }
    // app/build.gradle
    onesky {

    apiKey oneskyApiKey

    apiSecret oneskyApiSecret

    projectId oneskyProjectId
    locales “es”, “ar”, …

    }
    

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36. 5. Add tasks
    // plugin/src/main/kotlin/your/package/HelloPlugin.kt
    class YourPlugin : Plugin {

    override fun apply(project: Project) {

    with(project) {

    extensions.create(“yourExtension", YourExtension::class.java)

    tasks.create("yourTask1", YourTask1::class.java)

    tasks.create("yourTask2", YourTask2::class.java)

    tasks.create("yourTask3", YourTask3::class.java)

    }

    }

    }
    

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37. 5. Add tasks
    We can reuse
    // app/build.gradle
    apply plugin: ”your.plugin”
    // plugin/src/main/kotlin/your/package/HelloTask.kt
    open class HelloTask : DefaultTask() {

    @TaskAction

    fun hello() {

    println(“Hello”)
    }

    }
    

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38. 6. Add tests
    We can reuse
    class HelloTaskTest {

    @Test

    fun hello() {

    val project = ProjectBuilder.builder().build()

    val task = project.task("hello")

    assertTrue(task is HelloTask)

    }

    }
    

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39. 1. Create Java library project
    2. Convert to Kotlin
    3. Add properties file
    4. Define Plugin
    5. Add tasks
    6. Add tests
    7. Publish
    1. Build script 2. buildSrc 3. Standalone project
    1. Create buildSrc
    directory
    2. Add `build.gradle`
    3. Add tasks
    4. (Add tests)
    1. Add tasks
    

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40. It depends on your
    requirement
    • 1. Build script: I would recommend this only for
    small tasks
    • 2. buildSrc project: Suitable for project specific
    tasks
    • 3. Standalone project: You can use in multiple
    builds and share with other projects
    

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41. Gradle Script Kotlin
    Could be an option?
    • Could be when it becomes stable
    • We would be able to write tasks in Kotlin in
    `build.gradle.kts`
    

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42. 1. Build script (Kotlin)
    2. buildSrc (Kotlin)
    3. Standalone project (Kotlin)
    Everything is Kotlin
    app (Kotlin)
    

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43. Everything is Kotlin
    

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44. Off topic: Kotin migration
    of Cookpad
    Started migrating Java to Kotlin
    2016/11 2017/5
    40% done
    Migrated from Rake to Gradle
    2017/6
    Migrated tests
    2016/12
    

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45. Kentaro Takiguchi
    @rejasupotaro
    Let’s automate
    Thank you for listening!
    

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