Decisioning Logic

Positive Signals ✅

Only Kotlin .kt Source Files

Using Kotlin JVM Plugin

Uses the Kotlin Multiplatform Plugin

• NOTE: We could check the configuration in the future to see if it has multiple targets if deemed important.

Negative Signals ❌

Are there any java imports in the source files?

Imports starting with java., etc.

• Iterate through all main sourcesets for a simple .contains("import java.") List of all java stdlib packages: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/module-summary.html
• NOTE: This wouldn't find fully qualified references, but that could be added later if deemed important.

  Any non-multiplatform dependencies?

  Search for transitive artifacts that are not multiplatform compatible
• Use a list of well known libraries that are known to be multiplatform compatible, but then using the Maven Search API to look for the presence of the kotlin-tooling-metadata.json object via their JSON API at https://search.maven.org/.
  • Example request for ktor-client-core: https://search.maven.org/solrsearch/select?q=g%3Aio.ktor+AND+a%3Aktor-client-core+AND+v%3A2.1.0+AND+p%3Ajar+AND+l%3Akotlin-tooling-metadata&rows=1&wt=json
• NOTE: These results would be cached, the same way dependencies are today.
• NOTE: We could traverse local module dependencies, and check theirs as well if deemed important.

  Is this an Android Library Module?

  This tool works on kotlin("jvm") modules. If you are looking to move Android Libraries to Kotlin Multiplatform, the dependency-analysis-android-gradle-plugin will help give you advice on which modules can become kotlin("jvm") modules. After that, come back and use kmp-ready.

kmpReady Gradle Task

Could be applied to a specific module or the root so that all modules are scanned.

Run the kmpReady task and get a result like this:

┌─────────────────────────────────┬───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ Module                          │ KMP Ready Result                                                                                                      │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:android_app            │ Not KMP Ready                                                                                                         │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyMultiplatformCompatibleDependencies                                                                          │
│                                 │ ✅ HasOnlyKotlinFiles                                                                                                  │
│                                 │ ❌ IsAndroidApplication                                                                                                │
│                                 │ ❌ DoesNotHaveKotlinJvmOrMultiplatformPlugin                                                                           │
│                                 │ Applied Plugins                                                                                                       │
│                                 │  * com.android.build.gradle.AppPlugin                                                                                 │
│                                 │  * com.android.build.gradle.api.AndroidBasePlugin                                                                     │
│                                 │  * com.android.build.gradle.internal.plugins.AppPlugin                                                                │
│                                 │  * com.android.build.gradle.internal.plugins.VersionCheckPlugin                                                       │
│                                 │  * com.dropbox.gradle.plugins.dependencyguard.DependencyGuardPlugin                                                   │
│                                 │  * org.gradle.kotlin.dsl.provider.plugins.KotlinScriptBasePlugin                                                      │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:android_lib            │ Not KMP Ready                                                                                                         │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyMultiplatformCompatibleDependencies                                                                          │
│                                 │ ✅ HasOnlyKotlinFiles                                                                                                  │
│                                 │ ❌ IsAndroidLibrary                                                                                                    │
│                                 │ ❌ UsesJavaBaseImports                                                                                                 │
│                                 │ Java Base Library Usages                                                                                              │
│                                 │  * import java.util.Date                                                                                              │
│                                 │    /Users/samedwards/src/kmp-readiness/samples/android_lib/src/main/java/kmp4free/samples/android.lib/AndroidLib.kt:3 │
│                                 │ ❌ DoesNotHaveKotlinJvmOrMultiplatformPlugin                                                                           │
│                                 │ Applied Plugins                                                                                                       │
│                                 │  * com.android.build.gradle.LibraryPlugin                                                                             │
│                                 │  * com.android.build.gradle.api.AndroidBasePlugin                                                                     │
│                                 │  * com.android.build.gradle.internal.plugins.LibraryPlugin                                                            │
│                                 │  * com.android.build.gradle.internal.plugins.VersionCheckPlugin                                                       │
│                                 │  * org.gradle.kotlin.dsl.provider.plugins.KotlinScriptBasePlugin                                                      │
│                                 │  * org.jetbrains.kotlin.gradle.plugin.KotlinAndroidPluginWrapper                                                      │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:jvm                    │ Not KMP Ready                                                                                                         │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyKotlinFiles                                                                                                  │
│                                 │ ✅ KotlinPluginEnabled                                                                                                 │
│                                 │ ❌ IncompatibleDependencies                                                                                            │
│                                 │ * com.squareup.okhttp3:okhttp:4.9.3                                                                                   │
│                                 │ ❌ UsesJavaBaseImports                                                                                                 │
│                                 │ Java Base Library Usages                                                                                              │
│                                 │  * import java.util.Arrays                                                                                            │
│                                 │    /Users/samedwards/src/kmp-readiness/samples/jvm/src/main/java/kmp4free/samples/JvmLib.kt:3                         │
│                                 │  * val instant: java.time.Instant? = null                                                                             │
│                                 │    /Users/samedwards/src/kmp-readiness/samples/jvm/src/main/java/kmp4free/samples/JvmLib.kt:9                         │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:jvm_kmp4free           │ Not KMP Ready                                                                                                         │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyMultiplatformCompatibleDependencies                                                                          │
│                                 │ ✅ KotlinPluginEnabled                                                                                                 │
│                                 │ ❌ HasJavaFiles                                                                                                        │
│                                 │  * /Users/samedwards/src/kmp-readiness/samples/jvm_kmp4free/src/main/java/kmp4free/samples/ThisIsAJavaClass.java      │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:multiplatform          │ KMP Ready                                                                                                             │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyMultiplatformCompatibleDependencies                                                                          │
│                                 │ ✅ HasOnlyKotlinFiles                                                                                                  │
│                                 │ ✅ MultiplatformPluginAlreadyEnabled                                                                                   │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
├─────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ :samples:multiplatform_kmp4free │ KMP Ready                                                                                                             │
│                                 │ ---                                                                                                                   │
│                                 │ ✅ HasOnlyMultiplatformCompatibleDependencies                                                                          │
│                                 │ ✅ HasOnlyKotlinFiles                                                                                                  │
│                                 │ ✅ KotlinPluginEnabled                                                                                                 │
│                                 │                                                                                                                       │
│                                 │                                                                                                                       │
└─────────────────────────────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

Info/Debug Logging

Just pass use the info flag like ./gradlew kmpReady --info when you run the Gradle task and all the information collected that is used for decisioning is printed. Warning: This can be a TON of info on a large project.

Plugin Installation

Add the Snapshot Repo in your project's settings.gradle.kts

pluginManagement {
    repositories {
        // ...
        maven { url = "https://s01.oss.sonatype.org/content/repositories/snapshots/" }
    }
}

Add the Plugin on your project's build.gradle

plugins {
    id("com.handstandsam.kmp-ready") version "0.1.0-SNAPSHOT"
}