Enable warnings as errors and fix all warnings (#2451)

* Enable warnings as errors and fix all warnings

* Enable skip-metadata-version-check compiler setting

59 files changed, 305 insertions, 314 deletions

diff --git a/plugins/base/base-test-utils/src/main/kotlin/utils/assertHtmlEqualsIgnoringWhitespace.kt b/plugins/base/base-test-utils/src/main/kotlin/utils/assertHtmlEqualsIgnoringWhitespace.kt
index 95dcae4e..eeeea265 100644
--- a/plugins/base/base-test-utils/src/main/kotlin/utils/assertHtmlEqualsIgnoringWhitespace.kt
+++ b/plugins/base/base-test-utils/src/main/kotlin/utils/assertHtmlEqualsIgnoringWhitespace.kt
@@ -1,8 +1,8 @@
 package utils
 
-import junit.framework.Assert.assertEquals
 import org.jsoup.Jsoup
 import org.jsoup.nodes.Document
+import kotlin.test.assertEquals
 
 /**
  * Parses it using JSOUP, trims whitespace at the end of the line and asserts if they are equal
diff --git a/plugins/base/src/main/kotlin/parsers/MarkdownParser.kt b/plugins/base/src/main/kotlin/parsers/MarkdownParser.kt
index 75617e0c..d3006f33 100644
--- a/plugins/base/src/main/kotlin/parsers/MarkdownParser.kt
+++ b/plugins/base/src/main/kotlin/parsers/MarkdownParser.kt
@@ -74,7 +74,7 @@ open class MarkdownParser(
             ).flatMap { it.children }
         )
 
-    private fun horizontalRulesHandler(node: ASTNode) =
+    private fun horizontalRulesHandler() =
         DocTagsFromIElementFactory.getInstance(MarkdownTokenTypes.HORIZONTAL_RULE)
 
     private fun emphasisHandler(node: ASTNode) =
@@ -353,7 +353,7 @@ open class MarkdownParser(
             MarkdownElementTypes.ATX_5,
             MarkdownElementTypes.ATX_6,
             -> headersHandler(node)
-            MarkdownTokenTypes.HORIZONTAL_RULE -> horizontalRulesHandler(node)
+            MarkdownTokenTypes.HORIZONTAL_RULE -> horizontalRulesHandler()
             MarkdownElementTypes.STRONG -> strongHandler(node)
             MarkdownElementTypes.EMPH -> emphasisHandler(node)
             MarkdownElementTypes.FULL_REFERENCE_LINK,
diff --git a/plugins/base/src/main/kotlin/parsers/factories/DocTagsFromIElementFactory.kt b/plugins/base/src/main/kotlin/parsers/factories/DocTagsFromIElementFactory.kt
index a3cbcc2e..ea87dce8 100644
--- a/plugins/base/src/main/kotlin/parsers/factories/DocTagsFromIElementFactory.kt
+++ b/plugins/base/src/main/kotlin/parsers/factories/DocTagsFromIElementFactory.kt
@@ -54,6 +54,7 @@ object DocTagsFromIElementFactory {
             MarkdownTokenTypes.HTML_BLOCK_CONTENT       -> Text(body.orEmpty(), params = params + contentTypeParam("html"))
             else                                        -> CustomDocTag(children, params, type.name)
         }.let {
+            @Suppress("UNCHECKED_CAST")
             when (it) {
                 is List<*> -> it as List<DocTag>
                 else -> listOf(it as DocTag)
diff --git a/plugins/base/src/main/kotlin/renderers/html/HtmlRenderer.kt b/plugins/base/src/main/kotlin/renderers/html/HtmlRenderer.kt
index 05559469..7ce41866 100644
--- a/plugins/base/src/main/kotlin/renderers/html/HtmlRenderer.kt
+++ b/plugins/base/src/main/kotlin/renderers/html/HtmlRenderer.kt
@@ -367,8 +367,6 @@ open class HtmlRenderer(
         pageContext: ContentPage
     ) = // TODO: extension point there
         if (node.isImage()) {
-            //TODO: add imgAttrs parsing
-            val imgAttrs = node.extra.allOfType<SimpleAttr>().joinAttr()
             img(src = node.address, alt = node.altText)
         } else {
             println("Unrecognized resource type: $node")
@@ -377,17 +375,16 @@ open class HtmlRenderer(
     private fun FlowContent.buildRow(
         node: ContentGroup,
         pageContext: ContentPage,
-        sourceSetRestriction: Set<DisplaySourceSet>?,
-        style: Set<Style>
+        sourceSetRestriction: Set<DisplaySourceSet>?
     ) {
         node.children
             .filter { sourceSetRestriction == null || it.sourceSets.any { s -> s in sourceSetRestriction } }
             .takeIf { it.isNotEmpty() }
             ?.let {
                 when (pageContext) {
-                    is MultimoduleRootPage -> buildRowForMultiModule(node, it, pageContext, sourceSetRestriction, style)
-                    is ModulePage -> buildRowForModule(node, it, pageContext, sourceSetRestriction, style)
-                    else -> buildRowForContent(node, it, pageContext, sourceSetRestriction, style)
+                    is MultimoduleRootPage -> buildRowForMultiModule(node, it, pageContext, sourceSetRestriction)
+                    is ModulePage -> buildRowForModule(node, it, pageContext, sourceSetRestriction)
+                    else -> buildRowForContent(node, it, pageContext, sourceSetRestriction)
                 }
             }
     }
@@ -396,8 +393,7 @@ open class HtmlRenderer(
         contextNode: ContentGroup,
         toRender: List<ContentNode>,
         pageContext: ContentPage,
-        sourceSetRestriction: Set<DisplaySourceSet>?,
-        style: Set<Style>
+        sourceSetRestriction: Set<DisplaySourceSet>?
     ) {
         buildAnchor(contextNode)
         div(classes = "table-row") {
@@ -414,8 +410,7 @@ open class HtmlRenderer(
         contextNode: ContentGroup,
         toRender: List<ContentNode>,
         pageContext: ContentPage,
-        sourceSetRestriction: Set<DisplaySourceSet>?,
-        style: Set<Style>
+        sourceSetRestriction: Set<DisplaySourceSet>?
     ) {
         buildAnchor(contextNode)
         div(classes = "table-row") {
@@ -440,8 +435,7 @@ open class HtmlRenderer(
         contextNode: ContentGroup,
         toRender: List<ContentNode>,
         pageContext: ContentPage,
-        sourceSetRestriction: Set<DisplaySourceSet>?,
-        style: Set<Style>
+        sourceSetRestriction: Set<DisplaySourceSet>?
     ) {
         buildAnchor(contextNode)
         div(classes = "table-row") {
@@ -551,7 +545,7 @@ open class HtmlRenderer(
             else -> div(classes = "table") {
                 node.extra.extraHtmlAttributes().forEach { attributes[it.extraKey] = it.extraValue }
                 node.children.forEach {
-                    buildRow(it, pageContext, sourceSetRestriction, node.style)
+                    buildRow(it, pageContext, sourceSetRestriction)
                 }
             }
         }
diff --git a/plugins/base/src/main/kotlin/signatures/JvmSignatureUtils.kt b/plugins/base/src/main/kotlin/signatures/JvmSignatureUtils.kt
index b6841323..dc5a9543 100644
--- a/plugins/base/src/main/kotlin/signatures/JvmSignatureUtils.kt
+++ b/plugins/base/src/main/kotlin/signatures/JvmSignatureUtils.kt
@@ -163,16 +163,23 @@ interface JvmSignatureUtils {
         }
     }
 
-    fun <T : Documentable> WithExtraProperties<T>.stylesIfDeprecated(sourceSetData: DokkaSourceSet): Set<TextStyle> =
-        if (extra[Annotations]?.directAnnotations?.get(sourceSetData)?.any {
-                it.dri == DRI("kotlin", "Deprecated")
-                        || it.dri == DRI("java.lang", "Deprecated")
-            } == true) setOf(TextStyle.Strikethrough) else emptySet()
-
-    infix fun DFunction.uses(t: DTypeParameter): Boolean {
-        val allDris: List<DRI> = (listOfNotNull(receiver?.dri, *receiver?.type?.drisOfAllNestedBounds?.toTypedArray() ?: emptyArray()) +
-                parameters.flatMap { listOf(it.dri) + it.type.drisOfAllNestedBounds })
-        return t.dri in allDris
+    fun <T : Documentable> WithExtraProperties<T>.stylesIfDeprecated(sourceSetData: DokkaSourceSet): Set<TextStyle> {
+        val directAnnotations = extra[Annotations]?.directAnnotations?.get(sourceSetData) ?: emptyList()
+        val hasAnyDeprecatedAnnotation =
+            directAnnotations.any { it.dri == DRI("kotlin", "Deprecated") || it.dri == DRI("java.lang", "Deprecated") }
+
+        return if (hasAnyDeprecatedAnnotation) setOf(TextStyle.Strikethrough) else emptySet()
+    }
+
+    infix fun DFunction.uses(typeParameter: DTypeParameter): Boolean {
+        val parameterDris = parameters.flatMap { listOf(it.dri) + it.type.drisOfAllNestedBounds }
+        val receiverDris =
+            listOfNotNull(
+                receiver?.dri,
+                *receiver?.type?.drisOfAllNestedBounds?.toTypedArray() ?: emptyArray()
+            )
+        val allDris = parameterDris + receiverDris
+        return typeParameter.dri in allDris
     }
 
     /**
diff --git a/plugins/base/src/main/kotlin/signatures/KotlinSignatureProvider.kt b/plugins/base/src/main/kotlin/signatures/KotlinSignatureProvider.kt
index ba4b4131..642c01c3 100644
--- a/plugins/base/src/main/kotlin/signatures/KotlinSignatureProvider.kt
+++ b/plugins/base/src/main/kotlin/signatures/KotlinSignatureProvider.kt
@@ -13,10 +13,7 @@ import org.jetbrains.dokka.model.*
 import org.jetbrains.dokka.model.Nullable
 import org.jetbrains.dokka.model.TypeConstructor
 import org.jetbrains.dokka.model.properties.WithExtraProperties
-import org.jetbrains.dokka.pages.ContentKind
-import org.jetbrains.dokka.pages.ContentNode
-import org.jetbrains.dokka.pages.TextStyle
-import org.jetbrains.dokka.pages.TokenStyle
+import org.jetbrains.dokka.pages.*
 import org.jetbrains.dokka.plugability.DokkaContext
 import org.jetbrains.dokka.plugability.plugin
 import org.jetbrains.dokka.plugability.querySingle
@@ -96,12 +93,16 @@ class KotlinSignatureProvider(ctcc: CommentsToContentConverter, logger: DokkaLog
             }
         }
 
-    private fun actualTypealiasedSignature(c: DClasslike, sourceSet: DokkaSourceSet, aliasedType: Bound) =
-        contentBuilder.contentFor(
+    private fun actualTypealiasedSignature(c: DClasslike, sourceSet: DokkaSourceSet, aliasedType: Bound): ContentGroup {
+        @Suppress("UNCHECKED_CAST")
+        val deprecationStyles = (c as? WithExtraProperties<out Documentable>)
+            ?.stylesIfDeprecated(sourceSet)
+            ?: emptySet()
+
+        return contentBuilder.contentFor(
             c,
             ContentKind.Symbol,
-            setOf(TextStyle.Monospace) + ((c as? WithExtraProperties<out Documentable>)?.stylesIfDeprecated(sourceSet)
-                ?: emptySet()),
+            setOf(TextStyle.Monospace) + deprecationStyles,
             sourceSets = setOf(sourceSet)
         ) {
             keyword("actual ")
@@ -110,15 +111,24 @@ class KotlinSignatureProvider(ctcc: CommentsToContentConverter, logger: DokkaLog
             operator(" = ")
             signatureForProjection(aliasedType)
         }
+    }
 
-    @Suppress("UNCHECKED_CAST")
-    private fun <T : DClasslike> classlikeSignature(c: T): List<ContentNode> =
-        c.sourceSets.map { sourceSetData ->
-            (c as? WithExtraProperties<out DClasslike>)?.extra?.get(ActualTypealias)?.underlyingType?.get(sourceSetData)
-                ?.let {
-                    actualTypealiasedSignature(c, sourceSetData, it)
-                } ?: regularSignature(c, sourceSetData)
+    private fun <T : DClasslike> classlikeSignature(c: T): List<ContentNode> {
+        @Suppress("UNCHECKED_CAST")
+        val typeAliasUnderlyingType = (c as? WithExtraProperties<out DClasslike>)
+            ?.extra
+            ?.get(ActualTypealias)
+            ?.underlyingType
+
+        return c.sourceSets.map { sourceSetData ->
+            val sourceSetType = typeAliasUnderlyingType?.get(sourceSetData)
+            if (sourceSetType == null) {
+                regularSignature(c, sourceSetData)
+            } else {
+                actualTypealiasedSignature(c, sourceSetData, sourceSetType)
+            }
         }
+    }
 
     private fun <T : Documentable> PageContentBuilder.DocumentableContentBuilder.defaultValueAssign(
         d: WithExtraProperties<T>,
@@ -134,27 +144,33 @@ class KotlinSignatureProvider(ctcc: CommentsToContentConverter, logger: DokkaLog
         }
     }
 
-    private fun regularSignature(c: DClasslike, sourceSet: DokkaSourceSet) =
-        contentBuilder.contentFor(
+    private fun regularSignature(c: DClasslike, sourceSet: DokkaSourceSet): ContentGroup {
+        @Suppress("UNCHECKED_CAST")
+        val deprecationStyles = (c as? WithExtraProperties<out Documentable>)
+            ?.stylesIfDeprecated(sourceSet)
+            ?: emptySet()
+
+        return contentBuilder.contentFor(
             c,
             ContentKind.Symbol,
-            setOf(TextStyle.Monospace) + ((c as? WithExtraProperties<out Documentable>)?.stylesIfDeprecated(sourceSet)
-                ?: emptySet()),
+            setOf(TextStyle.Monospace) + deprecationStyles,
             sourceSets = setOf(sourceSet)
         ) {
             annotationsBlock(c)
             c.visibility[sourceSet]?.takeIf { it !in ignoredVisibilities }?.name?.let { keyword("$it ") }
             if (c.isExpectActual) keyword(if (sourceSet == c.expectPresentInSet) "expect " else "actual ")
             if (c is DClass) {
-               val modifier = if (c.modifier[sourceSet] !in ignoredModifiers)
+                val modifier =
+                    if (c.modifier[sourceSet] !in ignoredModifiers) {
                         when {
                             c.extra[AdditionalModifiers]?.content?.get(sourceSet)?.contains(ExtraModifiers.KotlinOnlyModifiers.Data) == true -> ""
                             c.modifier[sourceSet] is JavaModifier.Empty -> "${KotlinModifier.Open.name} "
-                            else -> c.modifier[sourceSet]?.name?.let { "$it " } ?: ""
+                            else -> c.modifier[sourceSet]?.name?.let { "$it " }
                         }
-                    else
-                        ""
-                modifier.takeIf { it.isNotEmpty() }?.let { keyword(it) }
+                    } else {
+                        null
+                    }
+                modifier?.takeIf { it.isNotEmpty() }?.let { keyword(it) }
             }
             when (c) {
                 is DClass -> {
@@ -232,6 +248,7 @@ class KotlinSignatureProvider(ctcc: CommentsToContentConverter, logger: DokkaLog
                 }
             }
         }
+    }
 
     /**
      * An example would be a primary constructor `class A(val s: String)`,
diff --git a/plugins/base/src/main/kotlin/templating/jsonMapperForPlugins.kt b/plugins/base/src/main/kotlin/templating/jsonMapperForPlugins.kt
index 71245778..98cabd72 100644
--- a/plugins/base/src/main/kotlin/templating/jsonMapperForPlugins.kt
+++ b/plugins/base/src/main/kotlin/templating/jsonMapperForPlugins.kt
@@ -49,6 +49,7 @@ private object FileSerializer : StdScalarSerializer<File>(File::class.java) {
     }
 }
 
+@Suppress("DEPRECATION") // for TypeFactory constructor, no way to use non-deprecated one, it's essentially identical
 private class PluginTypeFactory: TypeFactory(null) {
     override fun findClass(className: String): Class<out Any>? =
         Class.forName(className, true, DokkaBase::class.java.classLoader) ?: super.findClass(className)
diff --git a/plugins/base/src/main/kotlin/transformers/documentables/ActualTypealiasAdder.kt b/plugins/base/src/main/kotlin/transformers/documentables/ActualTypealiasAdder.kt
index a9b99840..58c601bc 100644
--- a/plugins/base/src/main/kotlin/transformers/documentables/ActualTypealiasAdder.kt
+++ b/plugins/base/src/main/kotlin/transformers/documentables/ActualTypealiasAdder.kt
@@ -66,7 +66,7 @@ class ActualTypealiasAdder : DocumentableTransformer {
         elements.map { element ->
             if (element.expectPresentInSet != null) {
                 typealiases[element.dri]?.let { ta ->
-                    element.withNewExtras(element.extra + ActualTypealias(ta.underlyingType)).let {
+                    val merged = element.withNewExtras(element.extra + ActualTypealias(ta.underlyingType)).let {
                         when(it) {
                             is DClass -> it.copy(sourceSets = element.sourceSets + ta.sourceSets)
                             is DEnum ->  it.copy(sourceSets = element.sourceSets + ta.sourceSets)
@@ -75,7 +75,9 @@ class ActualTypealiasAdder : DocumentableTransformer {
                             is DAnnotation -> it.copy(sourceSets = element.sourceSets + ta.sourceSets)
                             else -> throw IllegalStateException("${it::class.qualifiedName} ${it.name} cannot have copy its sourceSets")
                         }
-                    } as T
+                    }
+                    @Suppress("UNCHECKED_CAST")
+                    merged as T
                 } ?: element
             } else {
                 element
diff --git a/plugins/base/src/main/kotlin/transformers/documentables/DefaultDocumentableMerger.kt b/plugins/base/src/main/kotlin/transformers/documentables/DefaultDocumentableMerger.kt
index 6239ad6b..17e3cbcd 100644
--- a/plugins/base/src/main/kotlin/transformers/documentables/DefaultDocumentableMerger.kt
+++ b/plugins/base/src/main/kotlin/transformers/documentables/DefaultDocumentableMerger.kt
@@ -49,7 +49,7 @@ internal class DefaultDocumentableMerger(val context: DokkaContext) : Documentab
 
         fun mergeClashingElements(elements: List<Pair<T, Set<DokkaConfiguration.DokkaSourceSet>>>): List<T> =
             elements.groupBy { it.first.name }.values.flatMap { listOfDocumentableToSSIds ->
-                listOfDocumentableToSSIds.map { (documentable, sourceSets