Add the link to GitHub repo to the header if there are source links defined (#3235)

* Use URL from base plugin configuration
* Add integration test for the multi-module project that the homepage link exists everywhere

8 files changed, 170 insertions, 11 deletions

diff --git a/plugins/base/api/base.api b/plugins/base/api/base.api
index ae872558..13f877e3 100644
--- a/plugins/base/api/base.api
+++ b/plugins/base/api/base.api
@@ -105,20 +105,22 @@ public final class org/jetbrains/dokka/base/DokkaBaseConfiguration : org/jetbrai
 	public static final field mergeImplicitExpectActualDeclarationsDefault Z
 	public static final field separateInheritedMembersDefault Z
 	public fun <init> ()V
-	public fun <init> (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;)V
-	public synthetic fun <init> (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;Ljava/lang/String;)V
+	public synthetic fun <init> (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ljava/util/List;
 	public final fun component2 ()Ljava/util/List;
 	public final fun component3 ()Z
 	public final fun component4 ()Ljava/lang/String;
 	public final fun component5 ()Z
 	public final fun component6 ()Ljava/io/File;
-	public final fun copy (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;)Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;
-	public static synthetic fun copy$default (Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;ILjava/lang/Object;)Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;
+	public final fun component7 ()Ljava/lang/String;
+	public final fun copy (Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;Ljava/lang/String;)Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;
+	public static synthetic fun copy$default (Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;Ljava/util/List;Ljava/util/List;ZLjava/lang/String;ZLjava/io/File;Ljava/lang/String;ILjava/lang/Object;)Lorg/jetbrains/dokka/base/DokkaBaseConfiguration;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getCustomAssets ()Ljava/util/List;
 	public final fun getCustomStyleSheets ()Ljava/util/List;
 	public final fun getFooterMessage ()Ljava/lang/String;
+	public final fun getHomepageLink ()Ljava/lang/String;
 	public final fun getMergeImplicitExpectActualDeclarations ()Z
 	public final fun getSeparateInheritedMembers ()Z
 	public final fun getTemplatesDir ()Ljava/io/File;
@@ -126,6 +128,7 @@ public final class org/jetbrains/dokka/base/DokkaBaseConfiguration : org/jetbrai
 	public final fun setCustomAssets (Ljava/util/List;)V
 	public final fun setCustomStyleSheets (Ljava/util/List;)V
 	public final fun setFooterMessage (Ljava/lang/String;)V
+	public final fun setHomepageLink (Ljava/lang/String;)V
 	public final fun setMergeImplicitExpectActualDeclarations (Z)V
 	public final fun setSeparateInheritedMembers (Z)V
 	public final fun setTemplatesDir (Ljava/io/File;)V
diff --git a/plugins/base/src/main/kotlin/DokkaBaseConfiguration.kt b/plugins/base/src/main/kotlin/DokkaBaseConfiguration.kt
index 11184126..34195f65 100644
--- a/plugins/base/src/main/kotlin/DokkaBaseConfiguration.kt
+++ b/plugins/base/src/main/kotlin/DokkaBaseConfiguration.kt
@@ -14,7 +14,8 @@ public data class DokkaBaseConfiguration(
     var separateInheritedMembers: Boolean = separateInheritedMembersDefault,
     var footerMessage: String = defaultFooterMessage,
     var mergeImplicitExpectActualDeclarations: Boolean = mergeImplicitExpectActualDeclarationsDefault,
-    var templatesDir: File? = defaultTemplatesDir
+    var templatesDir: File? = defaultTemplatesDir,
+    var homepageLink: String? = null,
 ) : ConfigurableBlock {
     public companion object {
         public val defaultFooterMessage: String = "© ${Year.now().value} Copyright"
diff --git a/plugins/base/src/main/kotlin/renderers/html/htmlPreprocessors.kt b/plugins/base/src/main/kotlin/renderers/html/htmlPreprocessors.kt
index dc877605..dad013e2 100644
--- a/plugins/base/src/main/kotlin/renderers/html/htmlPreprocessors.kt
+++ b/plugins/base/src/main/kotlin/renderers/html/htmlPreprocessors.kt
@@ -111,6 +111,7 @@ public object AssetsInstaller : PageTransformer {
         "images/copy-successful-icon.svg",
         "images/theme-toggle.svg",
         "images/burger.svg",
+        "images/homepage.svg",
 
         // navigation icons
         "images/nav-icons/abstract-class.svg",
diff --git a/plugins/base/src/main/kotlin/renderers/html/innerTemplating/DefaultTemplateModelFactory.kt b/plugins/base/src/main/kotlin/renderers/html/innerTemplating/DefaultTemplateModelFactory.kt
index 3883bc4a..fe6f0089 100644
--- a/plugins/base/src/main/kotlin/renderers/html/innerTemplating/DefaultTemplateModelFactory.kt
+++ b/plugins/base/src/main/kotlin/renderers/html/innerTemplating/DefaultTemplateModelFactory.kt
@@ -86,10 +86,16 @@ public class DefaultTemplateModelFactory(
         return mapper
     }
 
-    override fun buildSharedModel(): TemplateMap = mapOf<String, Any>(
-        "footerMessage" to (configuration?.footerMessage?.takeIf { it.isNotEmpty() }
-            ?: DokkaBaseConfiguration.defaultFooterMessage)
-    )
+    override fun buildSharedModel(): TemplateMap {
+        val mapper = mutableMapOf<String, Any>()
+
+        mapper["footerMessage"] =
+            (configuration?.footerMessage?.takeIf(String::isNotBlank) ?: DokkaBaseConfiguration.defaultFooterMessage)
+
+        configuration?.homepageLink?.takeIf(String::isNotBlank)?.let { mapper["homepageLink"] = it }
+
+        return mapper
+    }
 
     private val DisplaySourceSet.comparableKey
         get() = sourceSetIDs.merged.let { it.scopeId + it.sourceSetName }
@@ -107,6 +113,7 @@ public class DefaultTemplateModelFactory(
                             rel = LinkRel.stylesheet,
                             href = if (resource.isAbsolute) resource else "$pathToRoot$resource"
                         )
+
                     resource.URIExtension == "js" ->
                         script(
                             type = ScriptType.textJavaScript,
@@ -117,6 +124,7 @@ public class DefaultTemplateModelFactory(
                             else
                                 async = true
                         }
+
                     resource.isImage() -> link(href = if (resource.isAbsolute) resource else "$pathToRoot$resource")
                     else -> null
                 }
@@ -125,6 +133,7 @@ public class DefaultTemplateModelFactory(
                 append(resourceHtml)
             }
         }
+
 }
 
 private class PrintDirective(val generateData: () -> String) : TemplateDirectiveModel {
@@ -144,7 +153,10 @@ private class PrintDirective(val generateData: () -> String) : TemplateDirective
     }
 }
 
-private class TemplateDirective(val configuration: DokkaConfiguration, val pathToRoot: String) : TemplateDirectiveModel {
+private class TemplateDirective(
+    val configuration: DokkaConfiguration,
+    val pathToRoot: String
+) : TemplateDirectiveModel {
     override fun execute(
         env: Environment,
         params: MutableMap<Any?, Any?>?,
@@ -170,6 +182,7 @@ private class TemplateDirective(val configuration: DokkaConfiguration, val pathT
                     Context(env, body)
                 )
             }
+
             "projectName" -> {
                 body ?: throw TemplateModelException(
                     "No directive body $commandName command."
@@ -183,6 +196,7 @@ private class TemplateDirective(val configuration: DokkaConfiguration, val pathT
                     Context(env, body)
                 )
             }
+
             else -> throw TemplateModelException(
                 "The parameter $PARAM_NAME $commandName is unknown"
             )
diff --git a/plugins/base/src/main/resources/dokka/images/homepage.svg b/plugins/base/src/main/resources/dokka/images/homepage.svg
new file mode 100644
index 00000000..a3d7602b
--- /dev/null
+++ b/plugins/base/src/main/resources/dokka/images/homepage.svg
@@ -0,0 +1,5 @@
+<!-- SOURCE: https://www.svgrepo.com/svg/416627/home-house-ui -->
+<svg fill="#ffffff" width="64px" height="64px" viewBox="0 0 512.00 512.00" xmlns="http://www.w3.org/2000/svg">
+    <path d="M256,0C114.615,0,0,114.615,0,256s114.615,256,256,256s256-114.615,256-256S397.385,0,256,0z M404.861,263.236 L404.861,263.236c-7.297,7.297-18.066,8.993-26.986,5.104v97.098c0,20.193-16.37,36.562-36.562,36.562H170.688 c-20.193,0-36.562-16.37-36.562-36.562v-97.098c-8.919,3.89-19.689,2.193-26.986-5.104c-9.519-9.519-9.519-24.952,0-34.471 L238.764,97.139h0c9.519-9.519,24.952-9.519,34.471,0l131.625,131.625C414.38,238.283,414.38,253.717,404.861,263.236z"/>
+    <path d="M286.469,267.938h-60.938c-6.731,0-12.188,5.457-12.188,12.188v73.125c0,6.731,5.457,12.188,12.188,12.188h60.938 c6.731,0,12.188-5.457,12.188-12.188v-73.125C298.656,273.394,293.2,267.938,286.469,267.938z"/>
+</svg>
diff --git a/plugins/base/src/main/resources/dokka/styles/style.css b/plugins/base/src/main/resources/dokka/styles/style.css
index 67a899a5..62b0ddbd 100644
--- a/plugins/base/src/main/resources/dokka/styles/style.css
+++ b/plugins/base/src/main/resources/dokka/styles/style.css
@@ -342,6 +342,7 @@ td:first-child {
 /* --- Navigation controls --- */
 .navigation-controls {
     display: flex;
+    margin-left: 4px;
 }
 
 @media (min-width: 760px) {
@@ -365,7 +366,6 @@ td:first-child {
     display: block;
     border-radius: 50%;
     background-color: inherit;
-    margin-left: 4px;
     padding: 0;
     border: none;
     cursor: pointer;
@@ -394,6 +394,36 @@ td:first-child {
 }
 /* /--- Navigation THEME --- */
 
+/* --- Navigation HOMEPAGE --- */
+.navigation-controls--homepage {
+    height: 40px;
+    width: 40px;
+    display: block;
+    border-radius: 50%;
+    cursor: pointer;
+}
+
+.navigation-controls--homepage a::before {
+    height: 100%;
+    width: 20px;
+    margin-left: 10px;
+    display: block;
+    content: "";
+    background: url("../images/homepage.svg");
+    background-size: 100% 100%;
+}
+
+.navigation-controls--homepage:hover {
+    background: var(--white-10);
+}
+
+@media (max-width: 759px) {
+    .navigation-controls--homepage {
+        display: none;
+    }
+}
+/* /--- Navigation HOMEPAGE --- */
+
 .navigation .platform-selector:not([data-active]) {
     color: #fff;
 }
diff --git a/plugins/base/src/main/resources/dokka/templates/includes/header.ftl b/plugins/base/src/main/resources/dokka/templates/includes/header.ftl
index d5c7a613..d399e633 100644
--- a/plugins/base/src/main/resources/dokka/templates/includes/header.ftl
+++ b/plugins/base/src/main/resources/dokka/templates/includes/header.ftl
@@ -21,6 +21,9 @@
         <@source_set_selector.display/>
     </div>
     <div class="navigation-controls">
+        <#if homepageLink?has_content>
+            <div class="navigation-controls--btn navigation-controls--homepage" id="homepage-link" role="button"><a href="${homepageLink}"></a></div>
+        </#if>
         <button class="navigation-controls--btn navigation-controls--theme" id="theme-toggle-button" type="button">switch theme</button>
         <div class="navigation-controls--btn navigation-controls--search" id="searchBar" role="button">search in API</div>
     </div>
diff --git a/plugins/base/src/test/kotlin/renderers/html/HeaderTest.kt b/plugins/base/src/test/kotlin/renderers/html/HeaderTest.kt
new file mode 100644
index 00000000..c19f965f
--- /dev/null
+++ b/plugins/base/src/test/kotlin/renderers/html/HeaderTest.kt
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2014-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package renderers.html
+
+import org.jetbrains.dokka.DokkaConfiguration
+import org.jetbrains.dokka.DokkaConfigurationImpl
+import org.jetbrains.dokka.PluginConfigurationImpl
+import org.jetbrains.dokka.base.DokkaBase
+import org.jetbrains.dokka.base.DokkaBaseConfiguration
+import org.jetbrains.dokka.base.templating.toJsonString
+import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
+import org.jetbrains.dokka.pages.RootPageNode
+import org.jetbrains.dokka.plugability.DokkaContext
+import org.jsoup.Jsoup
+import utils.TestOutputWriter
+import utils.TestOutputWriterPlugin
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+
+class HeaderTest : BaseAbstractTest() {
+    private val configuration = dokkaConfiguration {
+        sourceSets {
+            sourceSet {
+                name = "jvm"
+                sourceRoots = listOf("src/jvm")
+            }
+            sourceSet {
+                name = "js"
+                sourceRoots = listOf("src/js")
+            }
+        }
+    }
+
+    @Test
+    fun `should include homepage link if homepageLink is provided`() {
+        testRendering(
+            DokkaBaseConfiguration(homepageLink = "https://github.com/Kotlin/dokka/")
+        ) { _, _, writer ->
+            val renderedContent = navigationElement(writer)
+
+            val sourceLinkElement =
+                assertNotNull(renderedContent.getElementById("homepage-link"), "Source link element not found")
+            val aElement = assertNotNull(sourceLinkElement.selectFirst("a"))
+            assertEquals("https://github.com/Kotlin/dokka/", aElement.attr("href"))
+        }
+    }
+
+    @Test
+    fun `should not include homepage link by default`() {
+        testRendering(null) { _, _, writer ->
+            val renderedContent = navigationElement(writer)
+            assertNull(renderedContent.getElementById("homepage-link"), "Source link element found")
+        }
+    }
+
+    private fun testRendering(
+        baseConfiguration: DokkaBaseConfiguration?,
+        block: (RootPageNode, DokkaContext, writer: TestOutputWriter) -> Unit
+    ) {
+        fun configuration(): DokkaConfigurationImpl {
+            baseConfiguration ?: return configuration
+            return configuration.copy(
+                pluginsConfiguration = listOf(
+                    PluginConfigurationImpl(
+                        DokkaBase::class.java.canonicalName,
+                        DokkaConfiguration.SerializationFormat.JSON,
+                        toJsonString(baseConfiguration)
+                    )
+                )
+            )
+        }
+
+        val writerPlugin = TestOutputWriterPlugin()
+        testInline(
+            """
+            |/src/jvm/Test.kt
+            |fun test() {}
+            |/src/js/Test.kt
+            |fun test() {}
+            """,
+            configuration(),
+            pluginOverrides = listOf(writerPlugin)
+        ) {
+            renderingStage = { node, context ->
+                block(node, context, writerPlugin.writer)
+            }
+        }
+    }
+
+    private fun navigationElement(writer: TestOutputWriter) =
+        writer
+            .contents
+            .getValue("index.html")
+            .let(Jsoup::parse)
+            .select(".navigation")
+            .single()
+
+}