Learning Gradle

README.md

@@ -6,3 +6,4 @@ Mono repo for all public development
 
 * [Java](./java): Sandbox for all Java public development.
 * [Python](./python): Sandbox for all Python public development.
+* [Kotlin](./kotlin): Sandbox for all Kotlin public development.

kotlin/README.md

@@ -0,0 +1,3 @@
+# Kotlin Sandbox
+
+Somewhere to put any Kotlin code I'm playing with.

kotlin/gradle-tutorial/.gitattributes

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+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+
+# Binary files should be left untouched
+*.jar           binary
+

kotlin/gradle-tutorial/.gitignore

@@ -0,0 +1,8 @@
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build
+
+# Ignore Kotlin plugin data
+.kotlin

kotlin/gradle-tutorial/README.md

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+# Gradle Tutorial
+
+## Links
+
+* [Beginner Tutorial](https://docs.gradle.org/current/userguide/part1_gradle_init.html)
+
+## Notes
+
+* Where does gradle store it's local deps:
+
+```bash
+ls -l ~/.gradle/caches/modules-2/files-2.1/
+```
+
+### [Beginner Tutorial](https://docs.gradle.org/current/userguide/part1_gradle_init.html)
+
+#### Part 1: Initializing the Project
+
+* Help for init command:
+
+```bash
+macbookpro:gradle-tutorial mkwyche$ gradle help --task init
+Starting a Gradle Daemon (subsequent builds will be faster)
+```
+
+* Commands to generate:
+
+```bash
+# Generates the Kotlin Template Project which makes the wrapper etc...
+macbookpro:gradle-tutorial mkwyche$ gradle init --type kotlin-application --dsl kotlin
+# Post outcome is:
+macbookpro:gradle-tutorial mkwyche$ ls -l
+total 56
+-rw-r--r--  1 mkwyche  staff   287 Mar 24 21:43 _README.md
+drwxr-xr-x  4 mkwyche  staff   128 Mar 24 21:48 app
+drwxr-xr-x  4 mkwyche  staff   128 Mar 24 21:48 gradle
+-rw-r--r--  1 mkwyche  staff   194 Mar 24 21:48 gradle.properties
+-rwxr-xr-x  1 mkwyche  staff  8654 Mar 24 21:48 gradlew
+-rw-r--r--  1 mkwyche  staff  2896 Mar 24 21:48 gradlew.bat
+-rw-r--r--  1 mkwyche  staff   531 Mar 24 21:48 settings.gradle.kts
+```
+
+* Gain a better understanding of:
+  * [settings.gradle.kts](settings.gradle.kts)
+  * [build.gradle.kts](app/build.gradle.kts)
+  * [libs.versions.toml](gradle/libs.versions.toml)
+
+#### Part 2: Running Tasks
+
+* View available tasks:
+
+```bash
+./gradlew tasks
+```
+
+* TODO: Would be cool to see the tasks that are dependent on each task. Look
+  more into TaskInfo plugin.
+
+#### Part 3: Understanding Dependencies
+
+* Dependencies live in [build.gradle.kts](app/build.gradle.kts) .
+  * Scopes:
+    * implementation
+    * runtimeOnly
+    * testImplementation
+* Dependency Versions live in [libs.versions.toml](gradle/libs.versions.toml)
+  * By defining them there you can clean up the [build.gradle.kts](app/build.gradle.kts) to not need versions. This is
+    basically the same concept as parent poms.
+* ./gradlew app:dependencies == mvn dependency:tree
+
+#### Part 4: Applying Plugins
+
+* Adding in plugins. For example add this:
+
+```kotlin
+    // Apply the maven publish plugin
+    id("maven-publish")
+```
+
+To the plugins section. This will add Publishing Tasks to your list of tasks:
+
+```bash
+Publishing tasks
+----------------
+publish - Publishes all publications produced by this project.
+publishToMavenLocal - Publishes all Maven publications produced by this project to the local Maven cache.
+```
+
+* Publish to maven locally:
+
+```bash
+./gradlew :app:publishToMavenLocal
+```
+
+* Plugins extend Gradles capabilities by adding tasks, configurations and behavior to your build. They are the
+  main way to organize and reuse build logic.
+  * Plugin Types:
+    * Core plugins: Built into Gradle (e.g. java, application) . See full list of core plugins [here](https://docs.gradle.org/current/userguide/plugin_reference.html)
+    * Community Plugins: Published by others to the [Gradle Plugin Portal](https://plugins.gradle.org/)
+    * Custom Plugins: Created by you or your team for internal use.
+
+#### Part 5: Exploring Incremental Builds
+
+* Label Outcomes:
+  * UP-TO-DATE : Task that has been already executed and hasn't changed.
+  * SKIPPED : Task was explicitly prevented from running
+  * FROM-CACHE : Task output has been copied to local directory from previous builds in the build cache (caching feature)
+  * NO-SOURCE : Task was not executed because it's required inputs we not available.
+
+#### Part 6: Enabling the Gradle Build Cache
+
+* The build cache is here
+
+  ```bash
+  ls -l ~/.gradle/caches/build-cache-1/
+  ```
+* Remote build cache can likely be used to speed up build. 
+  * Develocity is a tool for that https://gradle.com/develocity/product/build-cache/
+
+
+

kotlin/gradle-tutorial/app/build.gradle.kts

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+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * This generated file contains a sample Kotlin application project to get you started.
+ * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/9.4.1/userguide/building_java_projects.html in the Gradle documentation.
+ */
+
+plugins {
+    // Apply the org.jetbrains.kotlin.jvm Plugin to add support for Kotlin.
+    alias(libs.plugins.kotlin.jvm)
+
+    // Task info dep
+    // id("org.barfuin.gradle.taskinfo") version "1.2.5" // Use the latest version
+
+    // Apply the application plugin to add support for building a CLI application in Java.
+    application
+
+    // Apply the maven publish plugin
+    id("maven-publish")
+}
+
+repositories {
+    // Use Maven Central for resolving dependencies.
+    mavenCentral()
+}
+
+dependencies {
+    // Use JUnit Jupiter for testing.
+    testImplementation(libs.junit.jupiter)
+
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+
+    // This dependency is used by the application.
+    implementation(libs.guava)
+    implementation(libs.mapstruct)
+}
+
+// Apply a specific Java toolchain to ease working on different environments.
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+application {
+    // Define the main class for the application.
+    mainClass = "org.example.AppKt"
+}
+
+tasks.named<Test>("test") {
+    // Use JUnit Platform for unit tests.
+    useJUnitPlatform()
+}
+
+// Example of registering a custom task...
+/*
+macbookpro:gradle-tutorial mkwyche$ ./gradlew :app:copyTask
+Calculating task graph as no cached configuration is available for tasks: :app:copyTask
+
+BUILD SUCCESSFUL in 1s
+Configuration cache entry stored.
+ */
+tasks.register<Copy>("copyTask") {
+    from("source")
+    into("target")
+    include("*.war")
+}
+
+// Understanding Dependencies Between Tasks
+/*
+macbookpro:gradle-tutorial mkwyche$ ./gradlew :app:greet
+Calculating task graph as no cached configuration is available for tasks: :app:greet
+
+> Task :app:hello
+Hello!
+
+> Task :app:greet
+How are you?
+
+BUILD SUCCESSFUL in 1s
+2 actionable tasks: 2 executed
+ */
+tasks.register("hello") {
+    doLast {
+        println("Hello!")
+    }
+}
+
+tasks.register("greet") {
+    doLast {
+        println("How are you?")
+    }
+    dependsOn("hello")
+}
+
+/**
+ * Publishing configuration
+ */
+publishing {
+    publications {
+        // Adds the information needed by the plugin to actually publish.
+        create<MavenPublication>("maven") {
+            groupId = "datadidit.gradle.tutorial"
+            artifactId = "beginner-tutorial"
+            version = "1.0-SNAPSHOT"
+
+            from(components["java"])
+        }
+    }
+}

kotlin/gradle-tutorial/app/src/main/kotlin/org/example/App.kt

@@ -0,0 +1,15 @@
+/*
+ * This source file was generated by the Gradle 'init' task
+ */
+package org.example
+
+class App {
+    val greeting: String
+        get() {
+            return "Hello World!"
+        }
+}
+
+fun main() {
+    println(App().greeting)
+}

kotlin/gradle-tutorial/app/src/test/kotlin/org/example/AppTest.kt

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+/*
+ * This source file was generated by the Gradle 'init' task
+ */
+package org.example
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.Assertions.assertNotNull
+
+class AppTest {
+    @Test
+    fun appHasAGreeting() {
+        val classUnderTest = App()
+        assertNotNull(classUnderTest.greeting, "app should have a greeting")
+    }
+}

kotlin/gradle-tutorial/gradle.properties

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+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/build_environment.html#sec:gradle_configuration_properties
+org.gradle.console=verbose
+org.gradle.caching=true
+org.gradle.configuration-cache=true
+

kotlin/gradle-tutorial/gradle/libs.versions.toml

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+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/version_catalogs.html#sec::toml-dependencies-format
+
+[versions]
+guava = "33.5.0-jre"
+junit-jupiter = "6.0.1"
+mapstruct = "1.6.3"
+
+[libraries]
+guava = { module = "com.google.guava:guava", version.ref = "guava" }
+mapstruct = { module = "org.mapstruct:mapstruct", version.ref = "mapstruct" }
+junit-jupiter = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junit-jupiter" }
+
+[plugins]
+kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version = "2.3.0" }

kotlin/gradle-tutorial/gradle/wrapper/gradle-wrapper.properties

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+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists