Migrate Kotlin documentation snippets

gradle/libs.versions.toml

@@ -92,13 +92,15 @@ protolayout = "1.3.0"
 reactive-streams = "1.0.4"
 recyclerview = "1.4.0"
 registryDigitalCredentials = "1.0.0-alpha04"
+room = "2.6.1"
 robolectric = "4.16.1"
 roborazzi = "1.59.0"
 spotless = "8.3.0"
 targetSdk = "37"
 tiles = "1.5.0"
 tracing = "1.3.0"
 truth = "1.4.4"
+turbine = "1.1.0"
 tvComposeMaterial3 = "1.1.0-beta01"
 validatorPush = "1.0.0-alpha09"
 version-catalog-update = "1.1.0"
@@ -206,6 +208,7 @@ androidx-protolayout-expression = { module = "androidx.wear.protolayout:protolay
 androidx-protolayout-material = { module = "androidx.wear.protolayout:protolayout-material", version.ref = "protolayout" }
 androidx-protolayout-material3 = { module = "androidx.wear.protolayout:protolayout-material3", version.ref = "protolayout" }
 androidx-recyclerview = { module = "androidx.recyclerview:recyclerview", version.ref = "recyclerview" }
+androidx-room-common = { module = "androidx.room:room-common", version.ref = "room" }
 androidx-registry-digitalcredentials-openid = { module = "androidx.credentials.registry:registry-digitalcredentials-openid", version.ref = "registryDigitalCredentials" }
 androidx-registry-digitalcredentials-mdoc = { module = "androidx.credentials.registry:registry-digitalcredentials-mdoc", version.ref = "registryDigitalCredentials" }
 androidx-registry-digitalcredentials-sdjwtvc = { module = "androidx.credentials.registry:registry-digitalcredentials-sdjwtvc", version.ref = "registryDigitalCredentials" }
@@ -252,6 +255,7 @@ androidx-test-core-ktx = { module = "androidx.test:core-ktx", version.ref = "and
 crossdeviceprompt = { module = "com.google.android.play:crossdeviceprompt", version.ref = "crossdeviceprompt" }
 firebase-ai = { module = "com.google.firebase:firebase-ai" }
 firebase-bom = { module = "com.google.firebase:firebase-bom", version.ref = "firebase-bom" }
+firebase-firestore = { module = "com.google.firebase:firebase-firestore" }
 glide-compose = { module = "com.github.bumptech.glide:compose", version.ref = "glide" }
 google-android-material = { module = "com.google.android.material:material", version.ref = "material" }
 google-ar-core = { module = "com.google.ar:core", version.ref = "google-ar-core" }
@@ -287,6 +291,7 @@ roborazzi-compose = { module = "io.github.takahirom.roborazzi:roborazzi-compose"
 roborazzi-rule = { module = "io.github.takahirom.roborazzi:roborazzi-junit-rule", version.ref = "roborazzi" }
 tv-compose-material = { module = "androidx.tv:tv-material", version.ref = "tvComposeMaterial3" }
 truth = { module = "com.google.truth:truth", version.ref = "truth" }
+turbine = { module = "app.cash.turbine:turbine", version.ref = "turbine" }
 validator-push = { module = "com.google.android.wearable.watchface.validator:validator-push", version.ref = "validatorPush" }
 wear-compose-material = { module = "androidx.wear.compose:compose-material", version.ref = "wearComposeMaterial" }
 wear-compose-material3 = { module = "androidx.wear.compose:compose-material3", version.ref = "wearComposeMaterial3" }

kotlin/build.gradle.kts

@@ -53,8 +53,22 @@ android {
     }
 }
 dependencies {
+    // AndroidX
+    implementation(libs.androidx.activity.ktx)
+    implementation(libs.androidx.lifecycle.runtime)
     implementation(libs.androidx.lifecycle.viewmodel.ktx)
+    implementation(libs.androidx.room.common)
+
+    // Firebase
+    implementation(platform(libs.firebase.bom))
+    implementation(libs.firebase.firestore)
+
+    // KotlinX
     implementation(libs.kotlinx.coroutines.android)
-    testImplementation(libs.kotlinx.coroutines.test)
+
+    // Testing
     testImplementation(libs.junit)
+    testImplementation(libs.kotlinx.coroutines.test)
+    testImplementation(libs.truth)
+    testImplementation(libs.turbine)
 }

kotlin/src/main/kotlin/com/example/android/basics/AdoptForLargeTeams.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2026 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.basics
+
+// [START android_kotlin_adopt_person]
+data class Person(var firstName: String?, var lastName: String?)
+// [END android_kotlin_adopt_person]
+
+fun String.foo(): String = this
+
+fun testExtensionFunction() {
+    // [START android_kotlin_adopt_foo]
+    // [START_EXCLUDE]
+    val placeholderBefore = ""
+    // [END_EXCLUDE]
+
+    val myString: String = "hello"
+    val fooString = myString.foo()
+
+    // [START_EXCLUDE]
+    val placeholderAfter = ""
+    // [END_EXCLUDE]
+    // [END android_kotlin_adopt_foo]
+}
+
+class Foo {
+    fun baz() {}
+    fun zap() {}
+}
+
+fun testLet() {
+    // [START android_kotlin_adopt_let]
+    val nullableFoo: Foo? = Foo()
+
+    // This lambda executes only if nullableFoo is not null
+    // and `foo` is of the non-nullable Foo type
+    nullableFoo?.let { foo ->
+        foo.baz()
+        foo.zap()
+    }
+    // [END android_kotlin_adopt_let]
+}
+
+fun testSmartCast() {
+    // [START android_kotlin_adopt_smartcast]
+    val nullableFoo: Foo? = null
+    if (nullableFoo != null) {
+        nullableFoo.baz() // Using !! or ?. isn't required; the Kotlin compiler infers non-nullability
+        nullableFoo.zap() // from guard condition; smart casts nullableFoo to Foo inside this block
+    }
+    // [END android_kotlin_adopt_smartcast]
+}