Add KMP convention plugin

build-logic/convention/build.gradle.kts

@@ -110,5 +110,9 @@ gradlePlugin {
             id = "nowinandroid.jvm.library"
             implementationClass = "JvmLibraryConventionPlugin"
         }
+        register("kmpLibrary") {
+            id = "nowinandroid.kmp.library"
+            implementationClass = "KmpLibraryConventionPlugin"
+        }
     }
 }

build-logic/convention/src/main/kotlin/KmpLibraryConventionPlugin.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 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.
+ */
+
+import com.google.samples.apps.nowinandroid.configureKotlinMultiplatform
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+
+/**
+ * A plugin that applies the Kotlin Multiplatform plugin and configures it for the project.
+ * https://github.com/cashapp/sqldelight/blob/master/buildLogic/multiplatform-convention/src/main/kotlin/app/cash/sqldelight/multiplatform/MultiplatformConventions.kt
+ */
+class KmpLibraryConventionPlugin: Plugin<Project> {
+    override fun apply(target: Project) {
+        with(target) {
+            plugins.apply("org.jetbrains.kotlin.multiplatform")
+            configureKotlinMultiplatform()
+        }
+    }
+}

build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/KotlinMultiplatform.kt

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2024 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.google.samples.apps.nowinandroid
+
+import org.gradle.api.Project
+import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
+import org.jetbrains.kotlin.gradle.dsl.kotlinExtension
+import org.jetbrains.kotlin.konan.target.HostManager
+
+internal fun Project.configureKotlinMultiplatform() {
+    (project.kotlinExtension as KotlinMultiplatformExtension).apply {
+        jvm()
+
+        js {
+            browser {
+                testTask {
+                    useKarma {
+                        useChromeHeadless()
+                    }
+                }
+            }
+            compilations.configureEach {
+                kotlinOptions {
+                    moduleKind = "umd"
+                }
+            }
+        }
+
+        // tier 1
+        linuxX64()
+        macosX64()
+        macosArm64()
+        iosSimulatorArm64()
+        iosX64()
+
+        // tier 2
+        linuxArm64()
+        watchosSimulatorArm64()
+        watchosX64()
+        watchosArm32()
+        watchosArm64()
+        tvosSimulatorArm64()
+        tvosX64()
+        tvosArm64()
+        iosArm64()
+
+        // tier 3
+        androidNativeArm32()
+        androidNativeArm64()
+        androidNativeX86()
+        androidNativeX64()
+        mingwX64()
+        watchosDeviceArm64()
+
+        // linking fails for the linux test build if not built on a linux host
+        // ensure the tests and linking for them is only done on linux hosts
+        project.tasks.named("linuxX64Test") { enabled = HostManager.hostIsLinux }
+        project.tasks.named("linkDebugTestLinuxX64") { enabled = HostManager.hostIsLinux }
+
+        project.tasks.named("mingwX64Test") { enabled = HostManager.hostIsMingw }
+        project.tasks.named("linkDebugTestMingwX64") { enabled = HostManager.hostIsMingw }
+    }
+}

gradle/libs.versions.toml

@@ -202,3 +202,4 @@ nowinandroid-android-lint = { id = "nowinandroid.android.lint", version = "unspe
 nowinandroid-android-room = { id = "nowinandroid.android.room", version = "unspecified" }
 nowinandroid-android-test = { id = "nowinandroid.android.test", version = "unspecified" }
 nowinandroid-jvm-library = { id = "nowinandroid.jvm.library", version = "unspecified" }
+nowinandroid-kmp-library = { id = "nowinandroid.kmp.library", version = "unspecified" }