Interface segregation in plugins api

3 files changed, 54 insertions, 46 deletions

diff --git a/core/src/main/kotlin/DokkaGenerator.kt b/core/src/main/kotlin/DokkaGenerator.kt
index b29a0da2..05eb3054 100644
--- a/core/src/main/kotlin/DokkaGenerator.kt
+++ b/core/src/main/kotlin/DokkaGenerator.kt
@@ -25,9 +25,7 @@ class DokkaGenerator(
     fun generate(): Unit {
 
         logger.debug("Initializing plugins")
-        val context = DokkaContext.from(configuration.pluginsClasspath)
-        logger.progress("Loaded plugins: ${context.pluginNames}")
-        logger.progress("Loaded: ${context.loadedListForDebug}")
+        val context = DokkaContext.create(configuration.pluginsClasspath, logger)
 
         configuration.passesConfigurations.map { pass ->
             AnalysisEnvironment(DokkaMessageCollector(logger), pass.analysisPlatform).run {
diff --git a/core/src/main/kotlin/plugability/DokkaContext.kt b/core/src/main/kotlin/plugability/DokkaContext.kt
index dcd3398e..7727329c 100644
--- a/core/src/main/kotlin/plugability/DokkaContext.kt
+++ b/core/src/main/kotlin/plugability/DokkaContext.kt
@@ -1,55 +1,75 @@
 package org.jetbrains.dokka.plugability
 
+import org.jetbrains.dokka.DokkaLogger
 import java.io.File
 import java.net.URLClassLoader
 import java.util.*
 import kotlin.reflect.KClass
 
+interface DokkaContext {
+    operator fun <T : Any, E : ExtensionPoint<T>> get(point: E): List<Extension<T>>
 
-class DokkaContext private constructor() {
+    fun <T : DokkaPlugin> plugin(kclass: KClass<T>): T?
+
+    val logger: DokkaLogger
+
+    companion object {
+        fun create(pluginsClasspath: Iterable<File>, logger: DokkaLogger): DokkaContext =
+            DokkaContextConfigurationImpl(logger).apply {
+                pluginsClasspath.map { it.relativeTo(File(".").absoluteFile).toURI().toURL() }
+                    .toTypedArray()
+                    .let { URLClassLoader(it, this.javaClass.classLoader) }
+                    .also { checkClasspath(it) }
+                    .let { ServiceLoader.load(DokkaPlugin::class.java, it) }
+                    .forEach { install(it) }
+            }.also { it.logInitialisationInfo() }
+    }
+}
+
+interface DokkaContextConfiguration {
+    fun addExtension(extension: Extension<*>)
+}
+
+private class DokkaContextConfigurationImpl(
+    override val logger: DokkaLogger
+) : DokkaContext, DokkaContextConfiguration {
     private val plugins = mutableMapOf<KClass<*>, DokkaPlugin>()
 
     internal val extensions = mutableMapOf<ExtensionPoint<*>, MutableList<Extension<*>>>()
 
     @Suppress("UNCHECKED_CAST")
-    operator fun <T: Any, E: ExtensionPoint<T>> get(point: E) = extensions[point] as List<Extension<T>>
-
-    @PublishedApi
-    internal fun plugin(kclass: KClass<*>) = plugins[kclass]
-
-    val pluginNames: List<String>
-        get() = plugins.values.map { it::class.qualifiedName.toString() }
+    override operator fun <T : Any, E : ExtensionPoint<T>> get(point: E) = extensions[point] as List<Extension<T>>
 
-    val loadedListForDebug
-        get() = extensions.run { keys + values.flatten() }.toList()
-            .joinToString(prefix = "[\n", separator = ",\n", postfix = "\n]") { "\t$it" }
+    @Suppress("UNCHECKED_CAST")
+    override fun <T : DokkaPlugin> plugin(kclass: KClass<T>) = plugins[kclass] as T
 
-    private fun install(plugin: DokkaPlugin) {
+    fun install(plugin: DokkaPlugin) {
         plugins[plugin::class] = plugin
+        plugin.context = this
         plugin.internalInstall(this)
     }
 
-    companion object {
-        fun from(pluginsClasspath: Iterable<File>) = DokkaContext().apply {
-            pluginsClasspath.map { it.relativeTo(File(".").absoluteFile).toURI().toURL() }
-                .toTypedArray()
-                .let { URLClassLoader(it, this.javaClass.classLoader) }
-                .also { checkClasspath(it) }
-                .let { ServiceLoader.load(DokkaPlugin::class.java, it) }
-                .forEach { install(it) }
-        }
+    override fun addExtension(extension: Extension<*>) {
+        extensions.getOrPut(extension.extensionPoint, ::mutableListOf) += extension
     }
 
-    private fun checkClasspath(classLoader: URLClassLoader) {
-        classLoader.findResource(javaClass.name.replace('.', '/') + ".class")?.also {
-            throw AssertionError(
-                "Dokka API found on plugins classpath. This will lead to subtle bugs. " +
-                        "Please fix your plugins dependencies or exclude dokka api artifact from plugin classpath"
-            )
-        }
-    }
+    fun logInitialisationInfo() {
+        val pluginNames: List<String> = plugins.values.map { it::class.qualifiedName.toString() }
+
+        val loadedListForDebug = extensions.run { keys + values.flatten() }.toList()
+            .joinToString(prefix = "[\n", separator = ",\n", postfix = "\n]") { "\t$it" }
+
+        logger.progress("Loaded plugins: ${pluginNames}")
+        logger.progress("Loaded: ${loadedListForDebug}")
 
-    internal fun addExtension(it: Extension<*>) {
-        extensions.getOrPut(it.extensionPoint, ::mutableListOf) += it
     }
 }
+
+private fun checkClasspath(classLoader: URLClassLoader) {
+    classLoader.findResource(DokkaContext::class.java.name.replace('.', '/') + ".class")?.also {
+        throw AssertionError(
+            "Dokka API found on plugins classpath. This will lead to subtle bugs. " +
+                    "Please fix your plugins dependencies or exclude dokka api artifact from plugin classpath"
+        )
+    }
+}
\ No newline at end of file
diff --git a/core/src/main/kotlin/plugability/DokkaPlugin.kt b/core/src/main/kotlin/plugability/DokkaPlugin.kt
index 60ca245c..663cf88e 100644
--- a/core/src/main/kotlin/plugability/DokkaPlugin.kt
+++ b/core/src/main/kotlin/plugability/DokkaPlugin.kt
@@ -3,12 +3,7 @@ package org.jetbrains.dokka.plugability
 import kotlin.properties.ReadOnlyProperty
 import kotlin.reflect.KProperty
 import kotlin.reflect.KProperty1
-import kotlin.reflect.KTypeProjection
 import kotlin.reflect.full.createInstance
-import kotlin.reflect.full.createType
-import kotlin.reflect.full.declaredMemberProperties
-import kotlin.reflect.jvm.isAccessible
-import kotlin.reflect.jvm.jvmErasure
 
 private typealias ExtensionDelegate<T> = ReadOnlyProperty<DokkaPlugin, Extension<T>>
 
@@ -18,10 +13,8 @@ abstract class DokkaPlugin {
     @PublishedApi
     internal var context: DokkaContext? = null
 
-    protected open fun install(context: DokkaContext) {}
-
     protected inline fun <reified T : DokkaPlugin> plugin(): T =
-        context?.plugin(T::class) as? T ?: T::class.createInstance().also { it.context = this.context }
+        context?.plugin(T::class) ?: T::class.createInstance().also { it.context = this.context }
 
     protected fun <T : Any> extensionPoint() =
         object : ReadOnlyProperty<DokkaPlugin, ExtensionPoint<T>> {
@@ -44,10 +37,7 @@ abstract class DokkaPlugin {
         }.also { thisRef.extensionDelegates += property }
     }
 
-    internal fun internalInstall(ctx: DokkaContext) {
-        context = ctx
-        install(ctx)
-
+    internal fun internalInstall(ctx: DokkaContextConfiguration) {
         extensionDelegates.asSequence()
             .filterIsInstance<KProperty1<DokkaPlugin, Extension<*>>>() // always true
             .map { it.get(this) }