[kpm] kgp-idea: Implement IdeaKpmProjectContainer

This container serves the purpose of transferring a already
serialized binary form of IdeaKpmProject to the IDE.

^KT-52568 In Progress

libraries/tools/kotlin-gradle-plugin-idea/src/main/kotlin/org/jetbrains/kotlin/gradle/kpm/idea/IdeaKpmProjectContainer.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+@file:Suppress("FunctionName")
+
+package org.jetbrains.kotlin.gradle.kpm.idea
+
+import java.io.Serializable
+
+fun IdeaKpmProjectContainer(project: ByteArray): IdeaKpmProjectBinaryContainer {
+    return IdeaKpmProjectBinaryContainerImpl(project)
+}
+
+fun IdeaKpmProjectContainer(project: IdeaKpmProject): IdeaKpmProjectInstanceContainer {
+    return IdeaKpmProjectInstanceContainerImpl(project)
+}
+
+sealed interface IdeaKpmProjectContainer<T : Any> : Serializable {
+    val project: T
+    val binaryOrNull: ByteArray?
+    val instanceOrNull: IdeaKpmProject?
+}
+
+interface IdeaKpmProjectBinaryContainer : IdeaKpmProjectContainer<ByteArray> {
+    override val instanceOrNull: Nothing? get() = null
+    override val binaryOrNull: ByteArray get() = project
+}
+
+interface IdeaKpmProjectInstanceContainer : IdeaKpmProjectContainer<IdeaKpmProject> {
+    override val instanceOrNull: IdeaKpmProject get() = project
+    override val binaryOrNull: Nothing? get() = null
+}
+
+private data class IdeaKpmProjectBinaryContainerImpl(override val project: ByteArray) : IdeaKpmProjectBinaryContainer {
+    override fun equals(other: Any?): Boolean {
+        if (other === this) return true
+        if (other !is IdeaKpmProjectBinaryContainer) return false
+        return other.project.contentEquals(this.project)
+    }
+
+    override fun hashCode(): Int {
+        return project.contentHashCode()
+    }
+
+    companion object {
+        const val serialVersionUID = 0L
+    }
+}
+
+private data class IdeaKpmProjectInstanceContainerImpl(
+    override val project: IdeaKpmProject
+) : IdeaKpmProjectInstanceContainer {
+    companion object {
+        const val serialVersionUID = 0L
+    }
+}

libraries/tools/kotlin-gradle-plugin-idea/src/test/kotlin/org/jetbrains/kotlin/gradle/kpm/idea/IdeaKpmProjectContainerTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.gradle.kpm.idea
+
+import org.jetbrains.kotlin.gradle.kpm.idea.testFixtures.TestIdeaKpmInstances
+import kotlin.test.*
+
+class IdeaKpmProjectContainerTest {
+
+    @Test
+    fun `test - binary container - equality`() {
+        val container1 = IdeaKpmProjectContainer(byteArrayOf(1))
+        val container2 = IdeaKpmProjectContainer(byteArrayOf(1))
+        val container3 = IdeaKpmProjectContainer(byteArrayOf(1, 2))
+
+        assertEquals(container1, container2)
+        assertNotEquals(container2, container3)
+    }
+
+    @Test
+    fun `test - instance container - equality`() {
+        val container1 = IdeaKpmProjectContainer(TestIdeaKpmInstances.simpleProject)
+        val container2 = IdeaKpmProjectContainer(TestIdeaKpmInstances.simpleProject.copy())
+        val container3 = IdeaKpmProjectContainer(TestIdeaKpmInstances.simpleProject.copy(gradlePluginVersion = "some.other.version"))
+
+        assertEquals(container1, container2)
+        assertNotEquals(container2, container3)
+    }
+
+    @Test
+    fun `test - binary container - instanceOrNull`() {
+        assertNull(IdeaKpmProjectContainer(byteArrayOf()).instanceOrNull)
+        assertNotNull(IdeaKpmProjectBinaryContainer::class.java.getMethod("getInstanceOrNull"))
+    }
+
+    @Test
+    fun `test - instance container - instanceOrNull`() {
+        assertSame(TestIdeaKpmInstances.simpleProject, IdeaKpmProjectContainer(TestIdeaKpmInstances.simpleProject).instanceOrNull)
+        assertNotNull(IdeaKpmProjectInstanceContainer::class.java.getMethod("getInstanceOrNull"))
+    }
+
+    @Test
+    fun `test - binary container - binaryOrNull`() {
+        val binary = byteArrayOf()
+        assertEquals(binary, IdeaKpmProjectContainer(binary).binaryOrNull)
+        assertNotNull(IdeaKpmProjectBinaryContainer::class.java.getMethod("getBinaryOrNull"))
+    }
+
+    @Test
+    fun `test - instance container - binaryOrNull`() {
+        assertNull(IdeaKpmProjectContainer(TestIdeaKpmInstances.simpleProject).binaryOrNull)
+        assertNotNull(IdeaKpmProjectInstanceContainer::class.java.getMethod("getBinaryOrNull"))
+    }
+}