Restructure the project to utilize included builds (#3174)

* Refactor and simplify artifact publishing
* Update Gradle to 8.4
* Refactor and simplify convention plugins and build scripts

Fixes #3132

---------

Co-authored-by: Adam <897017+aSemy@users.noreply.github.com>
Co-authored-by: Oleg Yukhnevich <whyoleg@gmail.com>

3 files changed, 154 insertions, 0 deletions

diff --git a/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt
new file mode 100644
index 00000000..5c5d1892
--- /dev/null
+++ b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2014-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.dokka.it.gradle
+
+import org.gradle.testkit.runner.BuildResult
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.internal.DefaultGradleRunner
+import org.gradle.tooling.GradleConnectionException
+import org.gradle.util.GradleVersion
+import org.jetbrains.dokka.it.AbstractIntegrationTest
+import java.io.File
+import java.net.URI
+import kotlin.test.BeforeTest
+
+public abstract class AbstractGradleIntegrationTest : AbstractIntegrationTest() {
+
+    @BeforeTest
+    public fun copyTemplates() {
+        File("projects").listFiles().orEmpty()
+            .filter { it.isFile }
+            .filter { it.name.startsWith("template.") }
+            .forEach { file -> file.copyTo(File(tempFolder, file.name)) }
+    }
+
+    public fun createGradleRunner(
+        buildVersions: BuildVersions,
+        vararg arguments: String,
+        jvmArgs: List<String> = listOf("-Xmx2G", "-XX:MaxMetaspaceSize=1G")
+    ): GradleRunner {
+        return GradleRunner.create()
+            .withProjectDir(projectDir)
+            .forwardOutput()
+            .withJetBrainsCachedGradleVersion(buildVersions.gradleVersion)
+            .withTestKitDir(File("build", "gradle-test-kit").absoluteFile)
+            .withArguments(
+                listOfNotNull(
+                    "-Pdokka_it_dokka_version=${System.getenv("DOKKA_VERSION")}",
+                    "-Pdokka_it_kotlin_version=${buildVersions.kotlinVersion}",
+                    buildVersions.androidGradlePluginVersion?.let { androidVersion ->
+                        "-Pdokka_it_android_gradle_plugin_version=$androidVersion"
+                    },
+                    * arguments
+                )
+            ).run { this as DefaultGradleRunner }
+            .withJvmArguments(jvmArgs)
+    }
+
+    public fun GradleRunner.buildRelaxed(): BuildResult {
+        return try {
+            build()
+        } catch (e: Throwable) {
+            val gradleConnectionException = e.withAllCauses().find { it is GradleConnectionException }
+            if (gradleConnectionException != null) {
+                gradleConnectionException.printStackTrace()
+                throw IllegalStateException("Assumed Gradle connection", gradleConnectionException)
+
+            }
+            throw e
+        }
+    }
+}
+
+private fun GradleRunner.withJetBrainsCachedGradleVersion(version: GradleVersion): GradleRunner {
+    return withGradleDistribution(
+        URI.create(
+            "https://cache-redirector.jetbrains.com/" +
+                    "services.gradle.org/distributions/" +
+                    "gradle-${version.version}-bin.zip"
+        )
+    )
+}
+
+private fun Throwable.withAllCauses(): Sequence<Throwable> {
+    val root = this
+    return sequence {
+        yield(root)
+        val cause = root.cause
+        if (cause != null && cause != root) {
+            yieldAll(cause.withAllCauses())
+        }
+    }
+}
diff --git a/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/BuildVersions.kt b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/BuildVersions.kt
new file mode 100644
index 00000000..ab387420
--- /dev/null
+++ b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/BuildVersions.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2014-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.dokka.it.gradle
+
+import org.gradle.util.GradleVersion
+
+public data class BuildVersions(
+    val gradleVersion: GradleVersion,
+    val kotlinVersion: String,
+    val androidGradlePluginVersion: String? = null,
+) {
+    public constructor(
+        gradleVersion: String,
+        kotlinVersion: String,
+        androidGradlePluginVersion: String? = null
+    ) : this(
+        gradleVersion = GradleVersion.version(gradleVersion),
+        kotlinVersion = kotlinVersion,
+        androidGradlePluginVersion = androidGradlePluginVersion
+    )
+
+    override fun toString(): String {
+        return buildString {
+            append("Gradle ${gradleVersion.version}, Kotlin $kotlinVersion")
+            if (androidGradlePluginVersion != null) {
+                append(", Android $androidGradlePluginVersion")
+            }
+        }
+    }
+
+    public companion object {
+        public fun permutations(
+            gradleVersions: List<String>,
+            kotlinVersions: List<String>,
+            androidGradlePluginVersions: List<String?> = listOf(null)
+        ): List<BuildVersions> {
+            return gradleVersions.distinct().flatMap { gradleVersion ->
+                kotlinVersions.distinct().flatMap { kotlinVersion ->
+                    androidGradlePluginVersions.distinct().map { androidVersion ->
+                        BuildVersions(
+                            gradleVersion = gradleVersion,
+                            kotlinVersion = kotlinVersion,
+                            androidGradlePluginVersion = androidVersion
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/TestEnvironment.kt b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/TestEnvironment.kt
new file mode 100644
index 00000000..174060aa
--- /dev/null
+++ b/dokka-integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/TestEnvironment.kt
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2014-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.dokka.it.gradle
+
+public object TestEnvironment {
+    public val isExhaustive: Boolean = checkNotNull(System.getenv("isExhaustive")) {
+        "Missing `isExhaustive` environment variable"
+    }.toBoolean()
+}
+
+/**
+ * Will only return values if [TestEnvironment.isExhaustive] is set to true
+ */
+public inline fun <reified T> ifExhaustive(vararg values: T): Array<out T> {
+    return if (TestEnvironment.isExhaustive) values else emptyArray()
+}