Render nested classlikes in navigation

plugins/base/src/main/kotlin/renderers/html/NavigationDataProvider.kt

@@ -73,18 +73,28 @@ abstract class NavigationDataProvider {
     }
 
     private fun ContentPage.navigableChildren(): List<NavigationNode> {
-        return if (this !is ClasslikePageNode) {
+        return if (this is ClasslikePage) {
+            return this.navigableChildren()
+        } else {
             children
                 .filterIsInstance<ContentPage>()
                 .map { visit(it) }
                 .sortedBy { it.name.toLowerCase() }
-        } else if (documentables.any { it is DEnum }) {
-            // no sorting for enum entries, should be the same as in source code
-            children
-                .filter { child -> child is WithDocumentables && child.documentables.any { it is DEnumEntry } }
-                .map { visit(it as ContentPage) }
+        }
+    }
+
+    private fun ClasslikePage.navigableChildren(): List<NavigationNode> {
+        // Classlikes should only have other classlikes as navigable children
+        val navigableChildren = children
+            .filterIsInstance<ClasslikePage>()
+            .map { visit(it) }
+
+        val isEnumPage = documentables.any { it is DEnum }
+        return if (isEnumPage) {
+            // no sorting for enum entries, should be the same order as in source code
+            navigableChildren
         } else {
-            emptyList()
+            navigableChildren.sortedBy { it.name.toLowerCase() }
         }
     }
 }

plugins/base/src/main/kotlin/renderers/html/NavigationPage.kt

@@ -49,8 +49,7 @@ class NavigationPage(
                         }
                     }
                     buildLink(node.dri, node.sourceSets.toList()) {
-                        // special condition for Enums as it has children enum entries in navigation
-                        val withIcon = node.icon != null && (node.children.isEmpty() || node.isEnum())
+                        val withIcon = node.icon != null
                         if (withIcon) {
                             // in case link text is so long that it needs to have word breaks,
                             // and it stretches to two or more lines, make sure the icon
@@ -69,10 +68,6 @@ class NavigationPage(
                 node.children.withIndex().forEach { (n, p) -> visit(p, "$navId-$n", renderer) }
             }
         }
-
-    private fun NavigationNode.isEnum(): Boolean {
-        return icon == NavigationNodeIcon.ENUM_CLASS || icon == NavigationNodeIcon.ENUM_CLASS_KT
-    }
 }
 
 data class NavigationNode(

plugins/base/src/test/kotlin/renderers/html/NavigationIconTest.kt

@@ -1,13 +1,11 @@
 package renderers.html
 
 import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
-import org.jsoup.Jsoup
-import org.jsoup.nodes.Element
-import org.jsoup.select.Elements
 import org.junit.jupiter.api.Test
-import utils.TestOutputWriter
 import utils.TestOutputWriterPlugin
 import kotlin.test.assertEquals
+import utils.navigationHtml
+import utils.selectNavigationGrid
 
 class NavigationIconTest : BaseAbstractTest() {
 
@@ -277,10 +275,4 @@ class NavigationIconTest : BaseAbstractTest() {
             }
         }
     }
-
-    private fun TestOutputWriter.navigationHtml(): Element = contents.getValue("navigation.html").let { Jsoup.parse(it) }
-
-    private fun Elements.selectNavigationGrid(): Element {
-        return this.select("div.overview").select("span.nav-link-grid").single()
-    }
 }

plugins/base/src/test/kotlin/renderers/html/NavigationTest.kt

@@ -0,0 +1,228 @@
+package renderers.html
+
+import org.jetbrains.dokka.base.renderers.html.NavigationNodeIcon
+import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
+import org.jsoup.nodes.Element
+import org.junit.jupiter.api.Test
+import utils.TestOutputWriterPlugin
+import kotlin.test.assertEquals
+import utils.navigationHtml
+
+class NavigationTest : BaseAbstractTest() {
+
+    private val configuration = dokkaConfiguration {
+        sourceSets {
+            sourceSet {
+                sourceRoots = listOf("src/")
+            }
+        }
+    }
+
+    @Test
+    fun `should have expandable classlikes`() {
+        val writerPlugin = TestOutputWriterPlugin()
+        testInline(
+            """
+            |/src/main/kotlin/com/example/WithInner.kt
+            |package com.example
+            |
+            |class WithInner {
+            |    // in-class functions should not be in navigation
+            |    fun a() {}
+            |    fun b() {}
+            |    fun c() {}
+            |
+            |    class InnerClass {}
+            |    interface InnerInterface {}
+            |    enum class InnerEnum {}
+            |    object InnerObject {}
+            |    annotation class InnerAnnotation {}
+            |    companion object CompanionObject {}
+            |}
+            """.trimIndent(),
+            configuration,
+            pluginOverrides = listOf(writerPlugin)
+        ) {
+            renderingStage = { _, _ ->
+                val content = writerPlugin.writer.navigationHtml().select("div.sideMenuPart")
+                assertEquals(9, content.size)
+
+                // Navigation menu should be the following, sorted by name:
+                // - root
+                //    - com.example
+                //       - WithInner
+                //          - CompanionObject
+                //          - InnerAnnotation
+                //          - InnerClass
+                //          - InnerEnum
+                //          - InnerInterface
+                //          - InnerObject
+
+                content[0].assertNavigationLink(
+                    id = "root-nav-submenu",
+                    text = "root",
+                    address = "index.html",
+                )
+
+                content[1].assertNavigationLink(
+                    id = "root-nav-submenu-0",
+                    text = "com.example",
+                    address = "root/com.example/index.html",
+                )
+
+                content[2].assertNavigationLink(
+                    id = "root-nav-submenu-0-0",
+                    text = "WithInner",
+                    address = "root/com.example/-with-inner/index.html",
+                    icon = NavigationNodeIcon.CLASS_KT
+                )
+
+                content[3].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-0",
+                    text = "CompanionObject",
+                    address = "root/com.example/-with-inner/-companion-object/index.html",
+                    icon = NavigationNodeIcon.OBJECT
+                )
+
+                content[4].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-1",
+                    text = "InnerAnnotation",
+                    address = "root/com.example/-with-inner/-inner-annotation/index.html",
+                    icon = NavigationNodeIcon.ANNOTATION_CLASS_KT
+                )
+
+                content[5].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-2",
+                    text = "InnerClass",
+                    address = "root/com.example/-with-inner/-inner-class/index.html",
+                    icon = NavigationNodeIcon.CLASS_KT
+                )
+
+                content[6].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-3",
+                    text = "InnerEnum",
+                    address = "root/com.example/-with-inner/-inner-enum/index.html",
+                    icon = NavigationNodeIcon.ENUM_CLASS_KT
+                )
+
+                content[7].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-4",
+                    text = "InnerInterface",
+                    address = "root/com.example/-with-inner/-inner-interface/index.html",
+                    icon = NavigationNodeIcon.INTERFACE_KT
+                )
+
+                content[8].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-5",
+                    text = "InnerObject",
+                    address = "root/com.example/-with-inner/-inner-object/index.html",
+                    icon = NavigationNodeIcon.OBJECT
+                )
+            }
+        }
+    }
+
+    @Test
+    fun `should be able to have deeply nested classlikes`() {
+        val writerPlugin = TestOutputWriterPlugin()
+        testInline(
+            """
+            |/src/main/kotlin/com/example/DeeplyNested.kt
+            |package com.example
+            |
+            |class DeeplyNested {
+            |    class FirstLevelClass {
+            |        interface SecondLevelInterface {
+            |            object ThirdLevelObject {
+            |                annotation class FourthLevelAnnotation {}
+            |            }
+            |        }
+            |    }
+            |}
+            """.trimIndent(),
+            configuration,
+            pluginOverrides = listOf(writerPlugin)
+        ) {
+            renderingStage = { _, _ ->
+                val content = writerPlugin.writer.navigationHtml().select("div.sideMenuPart")
+                assertEquals(7, content.size)
+
+                // Navigation menu should be the following
+                // - root
+                //    - com.example
+                //       - DeeplyNested
+                //          - FirstLevelClass
+                //             - SecondLevelInterface
+                //                - ThirdLevelObject
+                //                   - FourthLevelAnnotation
+
+                content[0].assertNavigationLink(
+                    id = "root-nav-submenu",
+                    text = "root",
+                    address = "index.html",
+                )
+
+                content[1].assertNavigationLink(
+                    id = "root-nav-submenu-0",
+                    text = "com.example",
+                    address = "root/com.example/index.html",
+                )
+
+                content[2].assertNavigationLink(
+                    id = "root-nav-submenu-0-0",
+                    text = "DeeplyNested",
+                    address = "root/com.example/-deeply-nested/index.html",
+                    icon = NavigationNodeIcon.CLASS_KT
+                )
+
+                content[3].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-0",
+                    text = "FirstLevelClass",
+                    address = "root/com.example/-deeply-nested/-first-level-class/index.html",
+                    icon = NavigationNodeIcon.CLASS_KT
+                )
+
+                content[4].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-0-0",
+                    text = "SecondLevelInterface",
+                    address = "root/com.example/-deeply-nested/-first-level-class/-second-level-interface/index.html",
+                    icon = NavigationNodeIcon.INTERFACE_KT
+                )
+
+                content[5].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-0-0-0",
+                    text = "ThirdLevelObject",
+                    address = "root/com.example/-deeply-nested/-first-level-class/-second-level-interface/" +
+                            "-third-level-object/index.html",
+                    icon = NavigationNodeIcon.OBJECT
+                )
+
+                content[6].assertNavigationLink(
+                    id = "root-nav-submenu-0-0-0-0-0-0",
+                    text = "FourthLevelAnnotation",
+                    address = "root/com.example/-deeply-nested/-first-level-class/-second-level-interface/" +
+                            "-third-level-object/-fourth-level-annotation/index.html",
+                    icon = NavigationNodeIcon.ANNOTATION_CLASS_KT
+                )
+            }
+        }
+    }
+
+    private fun Element.assertNavigationLink(
+        id: String, text: String, address: String, icon: NavigationNodeIcon? = null
+    ) {
+        assertEquals(id, this.id())
+
+        val link = this.selectFirst("a")
+        checkNotNull(link)
+        assertEquals(text, link.text())
+        assertEquals(address, link.attr("href"))
+        if (icon != null) {
+            val iconStyles =
+                this.selectFirst("div.overview span.nav-link-grid")?.child(0)?.classNames()?.toList() ?: emptyList()
+            assertEquals(3, iconStyles.size)
+            assertEquals("nav-link-child", iconStyles[0])
+            assertEquals(icon.style(), "${iconStyles[1]} ${iconStyles[2]}")
+        }
+    }
+}

plugins/base/src/test/kotlin/utils/HtmlUtils.kt

@@ -0,0 +1,11 @@
+package utils
+
+import org.jsoup.Jsoup
+import org.jsoup.nodes.Element
+import org.jsoup.select.Elements
+
+internal fun TestOutputWriter.navigationHtml(): Element = contents.getValue("navigation.html").let { Jsoup.parse(it) }
+
+internal fun Elements.selectNavigationGrid(): Element {
+    return this.select("div.overview").select("span.nav-link-grid").single()
+}