Allow to skip gradle tasks depending on Android if SKIP_ANDROID env variable is defined

Author: macisamuele

README.md

@@ -165,6 +165,8 @@ While developing, you can build, run pre-commits, checks & tests on the plugin u
 
 Make sure your tests are all green ✅ locally before submitting PRs.
 
+NOTE: If you don't have the [Android SDK](https://developer.android.com/studio/releases/sdk-tools) you can skip the Android related tasks by setting `SKIP_ANDROID` enviromental variable (tests will be run on the CI anyway).
+
 ## Contributing/Support
 
 Support for this project is offered in the [#swagger-gradle-codegen](https://kotlinlang.slack.com/archives/CU233PG2Z) channel on the Kotlinlang slack ([request an invite here](http://slack.kotlinlang.org/)).

samples/junit-tests/build.gradle

@@ -1,21 +1,10 @@
 plugins {
-    id("com.android.library")
-    id("kotlin-android")
+    id("kotlin")
     id("com.yelp.codegen.plugin")
     id("io.gitlab.arturbosch.detekt")
     id("kotlin-kapt")
 }
 
-android {
-    compileSdkVersion = 28
-    defaultConfig {
-        minSdkVersion 21
-        targetSdkVersion 28
-        versionCode = 1
-        versionName = "1.0"
-    }
-}
-
 dependencies {
     // Kotlin
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.70"

samples/junit-tests/src/main/AndroidManifest.xml

@@ -17,10 +17,27 @@ pluginManagement {
     }
 }
 
-include(
-        ":samples:junit-tests",
+include(":samples:junit-tests")
+
+if (shouldIncludeAndroidProjects()) {
+    include(
         ":samples:kotlin-android",
         ":samples:kotlin-coroutines",
-        ":samples:groovy-android")
+        ":samples:groovy-android"
+    )
+}
 
 includeBuild("gradle-plugin")
+
+fun shouldIncludeAndroidProjects(): Boolean {
+    if (System.getenv("CI") != null) {
+        // Ensure that on CI systems we run all the gradle tasks (including the Android specific ones)
+        return true;
+    }
+
+    if (System.getenv("SKIP_ANDROID") != null) {
+        return false;
+    }
+
+    return true;
+}