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

* Enable warnings as errors and fix all warnings

* Enable skip-metadata-version-check compiler setting

21 files changed, 105 insertions, 166 deletions

diff --git a/plugins/base/src/test/kotlin/basic/DRITest.kt b/plugins/base/src/test/kotlin/basic/DRITest.kt
index 57e05858..3a4ff84d 100644
--- a/plugins/base/src/test/kotlin/basic/DRITest.kt
+++ b/plugins/base/src/test/kotlin/basic/DRITest.kt
@@ -190,7 +190,7 @@ class DRITest : BaseAbstractTest() {
         ) {
             pagesGenerationStage = { module ->
                 val sampleClass = module.dfs { it.name == "Sample" } as ClasslikePageNode
-                val classDocumentable = sampleClass.documentable as DClass
+                val classDocumentable = sampleClass.documentables.firstOrNull() as DClass
 
                 assertEquals( "example/Sample///PointingToDeclaration/", sampleClass.dri.first().toString())
                 assertEquals("example/Sample///PointingToGenericParameters(0)/", classDocumentable.generics.first().dri.toString())
@@ -224,7 +224,7 @@ class DRITest : BaseAbstractTest() {
             pagesGenerationStage = { module ->
                 val sampleClass = module.dfs { it.name == "Sample" } as ClasslikePageNode
                 val functionNode = sampleClass.children.first { it.name == "genericFun" } as MemberPageNode
-                val functionDocumentable = functionNode.documentable as DFunction
+                val functionDocumentable = functionNode.documentables.firstOrNull() as DFunction
                 val parameter = functionDocumentable.parameters.first()
 
                 assertEquals("example/Sample/genericFun/#kotlin.String/PointingToDeclaration/", functionNode.dri.first().toString())
@@ -269,9 +269,10 @@ class DRITest : BaseAbstractTest() {
                 val sampleClass = module.dfs { it.name == "Sample" } as ClasslikePageNode
                 val sampleInner = sampleClass.children.first { it.name == "SampleInner" } as ClasslikePageNode
                 val foo = sampleInner.children.first { it.name == "foo" } as MemberPageNode
-                val documentable = foo.documentable as DFunction
+                val documentable = foo.documentables.firstOrNull() as DFunction
 
-                assertEquals((sampleClass.documentable as WithGenerics).generics.first().dri.toString(), (documentable.type as TypeParameter).dri.toString())
+                val generics = (sampleClass.documentables.firstOrNull() as WithGenerics).generics
+                assertEquals(generics.first().dri.toString(), (documentable.type as TypeParameter).dri.toString())
                 assertEquals(0, documentable.generics.size)
             }
         }
@@ -298,7 +299,7 @@ class DRITest : BaseAbstractTest() {
         ) {
             pagesGenerationStage = { module ->
                 val extensionFunction = module.dfs { it.name == "extensionFunction" } as MemberPageNode
-                val documentable = extensionFunction.documentable as DFunction
+                val documentable = extensionFunction.documentables.firstOrNull() as DFunction
 
                 assertEquals(
                     "example//extensionFunction/kotlin.collections.List[TypeParam(bounds=[kotlin.Any?])]#/PointingToDeclaration/",
diff --git a/plugins/base/src/test/kotlin/content/ContentInDescriptionTest.kt b/plugins/base/src/test/kotlin/content/ContentInDescriptionTest.kt
index b44eb651..e5533a7e 100644
--- a/plugins/base/src/test/kotlin/content/ContentInDescriptionTest.kt
+++ b/plugins/base/src/test/kotlin/content/ContentInDescriptionTest.kt
@@ -1,9 +1,9 @@
 package content
 
-import junit.framework.Assert.assertEquals
 import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
 import org.jetbrains.dokka.model.doc.*
 import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
 import kotlin.test.assertTrue
 
 class ContentInDescriptionTest : BaseAbstractTest() {
diff --git a/plugins/base/src/test/kotlin/content/params/ContentForParamsTest.kt b/plugins/base/src/test/kotlin/content/params/ContentForParamsTest.kt
index 664b8282..50580afc 100644
--- a/plugins/base/src/test/kotlin/content/params/ContentForParamsTest.kt
+++ b/plugins/base/src/test/kotlin/content/params/ContentForParamsTest.kt
@@ -1412,7 +1412,7 @@ class ContentForParamsTest : BaseAbstractTest() {
                     it is MemberPageNode && it.dri.first()
                         .toString() == "test/Main/sample/#java.lang.String#java.lang.String/PointingToDeclaration/"
                 } as MemberPageNode
-                val forJvm = (sampleFunction.documentable as DFunction).parameters.mapNotNull {
+                val forJvm = (sampleFunction.documentables.firstOrNull() as DFunction).parameters.mapNotNull {
                     val jvm = it.documentation.keys.first { it.analysisPlatform == Platform.jvm }
                     it.documentation[jvm]
                 }
diff --git a/plugins/base/src/test/kotlin/content/properties/ContentForClassWithParamsAndPropertiesTest.kt b/plugins/base/src/test/kotlin/content/properties/ContentForClassWithParamsAndPropertiesTest.kt
index 5bd152dc..164fa62d 100644
--- a/plugins/base/src/test/kotlin/content/properties/ContentForClassWithParamsAndPropertiesTest.kt
+++ b/plugins/base/src/test/kotlin/content/properties/ContentForClassWithParamsAndPropertiesTest.kt
@@ -24,7 +24,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
         propertyTest { rootPage ->
             val node = rootPage.dfs { it.name == "LoadInitialParams" } as ClasslikePageNode
             val actualDocsForPlaceholdersEnabled =
-                (node.documentable as DClass).constructors.first().parameters.find { it.name == "placeholdersEnabled" }
+                (node.documentables.firstOrNull() as DClass).constructors.first().parameters.find { it.name == "placeholdersEnabled" }
                     ?.documentation?.entries?.first()?.value
             assertEquals(DocumentationNode(listOf(docsForPlaceholdersEnabled)), actualDocsForPlaceholdersEnabled)
         }
@@ -35,7 +35,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
         propertyTest { rootPage ->
             val node = rootPage.dfs { it.name == "LoadInitialParams" } as ClasslikePageNode
             val actualDocsForRequestedLoadSize =
-                (node.documentable as DClass).constructors.first().parameters.find { it.name == "requestedLoadSize" }
+                (node.documentables.firstOrNull() as DClass).constructors.first().parameters.find { it.name == "requestedLoadSize" }
                     ?.documentation?.entries?.first()?.value
             assertEquals(DocumentationNode(listOf(docsForRequestedLoadSize)), actualDocsForRequestedLoadSize)
         }
@@ -47,7 +47,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
             val node = rootPage.dfs { it.name == "LoadInitialParams" } as ClasslikePageNode
 
             val actualDocsForRequestedInitialKey =
-                (node.documentable as DClass).constructors.first().parameters.find { it.name == "requestedInitialKey" }
+                (node.documentables.firstOrNull() as DClass).constructors.first().parameters.find { it.name == "requestedInitialKey" }
                     ?.documentation?.entries?.first()?.value
             assertEquals(DocumentationNode(listOf(docsForRequestedInitialKey)), actualDocsForRequestedInitialKey)
         }
@@ -71,7 +71,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
             val node = rootPage.dfs { it.name == "LoadInitialParams" } as ClasslikePageNode
 
             val actualDocs =
-                (node.documentable as DClass).constructors.first().documentation.entries.first().value
+                (node.documentables.firstOrNull() as DClass).constructors.first().documentation.entries.first().value
             assertEquals(DocumentationNode(listOf(constructorDocs, docsForParam)), actualDocs)
         }
     }
@@ -94,7 +94,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
             val node = rootPage.dfs { it.name == "LoadInitialParams" } as ClasslikePageNode
 
             val actualDocs =
-                (node.documentable as DClass).documentation.entries.first().value
+                (node.documentables.firstOrNull() as DClass).documentation.entries.first().value
             assertEquals(
                 DocumentationNode(
                     listOf(
@@ -129,7 +129,7 @@ class ContentForClassWithParamsAndPropertiesTest : BaseAbstractTest() {
             val node = rootPage.dfs { it.name == "ItemKeyedDataSource" } as ClasslikePageNode
 
             val actualDocs =
-                (node.documentable as DClass).properties.first().documentation.entries.first().value
+                (node.documentables.firstOrNull() as DClass).properties.first().documentation.entries.first().value
             assertEquals(
                 DocumentationNode(listOf(ownDescription)),
                 actualDocs
diff --git a/plugins/base/src/test/kotlin/content/receiver/ContentForReceiverTest.kt b/plugins/base/src/test/kotlin/content/receiver/ContentForReceiverTest.kt
index e566320c..d7399914 100644
--- a/plugins/base/src/test/kotlin/content/receiver/ContentForReceiverTest.kt
+++ b/plugins/base/src/test/kotlin/content/receiver/ContentForReceiverTest.kt
@@ -1,7 +1,5 @@
 package content.receiver
 
-import junit.framework.Assert.assertEquals
-import junit.framework.Assert.assertNotNull
 import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
 import org.jetbrains.dokka.model.dfs
 import org.jetbrains.dokka.model.doc.Receiver
@@ -11,6 +9,8 @@ import org.jetbrains.dokka.pages.ContentText
 import org.jetbrains.dokka.pages.MemberPageNode
 import org.junit.jupiter.api.Test
 import utils.docs
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
 
 class ContentForReceiverTest: BaseAbstractTest() {
     private val testConfiguration = dokkaConfiguration {
@@ -40,7 +40,7 @@ class ContentForReceiverTest: BaseAbstractTest() {
                 with(module.packages.flatMap { it.functions }.first()){
                     val receiver = docs().firstOrNull { it is Receiver }
                     assertNotNull(receiver)
-                    val content = receiver?.dfs { it is Text } as Text
+                    val content = receiver.dfs { it is Text } as Text
                     assertEquals("docs for string", content.body)
                 }
             }
diff --git a/plugins/base/src/test/kotlin/expect/AbstractExpectTest.kt b/plugins/base/src/test/kotlin/expect/AbstractExpectTest.kt
index d1b8153d..1d86f219 100644
--- a/plugins/base/src/test/kotlin/expect/AbstractExpectTest.kt
+++ b/plugins/base/src/test/kotlin/expect/AbstractExpectTest.kt
@@ -52,7 +52,7 @@ abstract class AbstractExpectTest(
         excludes: List<String>,
         timeout: Long = 500
     ) {
-        obtained?.let { path ->
+        obtained?.let { _ ->
             val (res, out, err) = runDiff(expected, obtained, excludes, timeout)
             assertTrue(res == 0, "Outputs differ:\nstdout - $out\n\nstderr - ${err ?: ""}")
         } ?: throw AssertionError("obtained path is null")
diff --git a/plugins/base/src/test/kotlin/expectActuals/ExpectActualsTest.kt b/plugins/base/src/test/kotlin/expectActuals/ExpectActualsTest.kt
index e7c45abd..13d4b456 100644
--- a/plugins/base/src/test/kotlin/expectActuals/ExpectActualsTest.kt
+++ b/plugins/base/src/test/kotlin/expectActuals/ExpectActualsTest.kt
@@ -43,42 +43,42 @@ class ExpectActualsTest : BaseAbstractTest() {
                     sourceRoots = listOf("src/commonN2Main/kotlin/pageMerger/Test.kt")
                     dependentSourceSets = setOf(common.value.sourceSetID)
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
                     dependentSourceSets = setOf(commonJ.value.sourceSetID)
                     sourceRoots = listOf("src/jsMain/kotlin/pageMerger/Test.kt")
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
                     dependentSourceSets = setOf(commonJ.value.sourceSetID)
                     sourceRoots = listOf("src/jvmMain/kotlin/pageMerger/Test.kt")
                 }
-                val linuxX64 = sourceSet {
+                sourceSet {
                     name = "linuxX64"
                     displayName = "linuxX64"
                     analysisPlatform = "native"
                     dependentSourceSets = setOf(commonN1.value.sourceSetID)
                     sourceRoots = listOf("src/linuxX64Main/kotlin/pageMerger/Test.kt")
                 }
-                val mingwX64 = sourceSet {
+                sourceSet {
                     name = "mingwX64"
                     displayName = "mingwX64"
                     analysisPlatform = "native"
                     dependentSourceSets = setOf(commonN1.value.sourceSetID)
                     sourceRoots = listOf("src/mingwX64Main/kotlin/pageMerger/Test.kt")
                 }
-                val iosArm64 = sourceSet {
+                sourceSet {
                     name = "iosArm64"
                     displayName = "iosArm64"
                     analysisPlatform = "native"
                     dependentSourceSets = setOf(commonN2.value.sourceSetID)
                     sourceRoots = listOf("src/iosArm64Main/kotlin/pageMerger/Test.kt")
                 }
-                val iosX64 = sourceSet {
+                sourceSet {
                     name = "iosX64"
                     displayName = "iosX64"
                     analysisPlatform = "native"
@@ -149,19 +149,19 @@ class ExpectActualsTest : BaseAbstractTest() {
                 val noClass = allChildren.filter { it.name == "A" }
                 assertTrue(commonJ.size == 1) { "There can be only one [jvm, js]A page" }
                 assertTrue(
-                    commonJ.first().documentable?.sourceSets?.map { it.displayName }
+                    commonJ.first().documentables.firstOrNull()?.sourceSets?.map { it.displayName }
                         ?.containsAll(listOf("commonJ", "js", "jvm")) ?: false
                 ) { "A(jvm, js)should have commonJ, js, jvm sources" }
 
                 assertTrue(commonN1.size == 1) { "There can be only one [mingwX64, linuxX64]A page" }
                 assertTrue(
-                    commonN1.first().documentable?.sourceSets?.map { it.displayName }
+                    commonN1.first().documentables.firstOrNull()?.sourceSets?.map { it.displayName }
                         ?.containsAll(listOf("commonN1", "linuxX64", "mingwX64")) ?: false
                 ) { "[mingwX64, linuxX64]A should have commonN1, linuxX64, mingwX64 sources" }
 
                 assertTrue(commonN2.size == 1) { "There can be only one [iosX64, iosArm64]A page" }
                 assertTrue(
-                    commonN2.first().documentable?.sourceSets?.map { it.displayName }
+                    commonN2.first().documentables.firstOrNull()?.sourceSets?.map { it.displayName }
                         ?.containsAll(listOf("commonN2", "iosArm64", "iosX64")) ?: false
                 ) { "[iosX64, iosArm64]A should have commonN2, iosArm64, iosX64 sources" }
 
diff --git a/plugins/base/src/test/kotlin/filter/JavaVisibilityFilterTest.kt b/plugins/base/src/test/kotlin/filter/JavaVisibilityFilterTest.kt
index e6acec92..efab9aba 100644
--- a/plugins/base/src/test/kotlin/filter/JavaVisibilityFilterTest.kt
+++ b/plugins/base/src/test/kotlin/filter/JavaVisibilityFilterTest.kt
@@ -225,6 +225,7 @@ class JavaVisibilityFilterTest : BaseAbstractTest() {
     )
 
     companion object TestDataSources {
+        @Suppress("DEPRECATION") // for includeNonPublic
         val globalExcludes = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -234,6 +235,7 @@ class JavaVisibilityFilterTest : BaseAbstractTest() {
             }
         }
 
+        @Suppress("DEPRECATION") // for includeNonPublic
         val globalIncludes = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -243,6 +245,7 @@ class JavaVisibilityFilterTest : BaseAbstractTest() {
             }
         }
 
+        @Suppress("DEPRECATION") // for includeNonPublic
         val globalIncludesPackageExcludes = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -251,17 +254,18 @@ class JavaVisibilityFilterTest : BaseAbstractTest() {
                     perPackageOptions = mutableListOf(
                         PackageOptionsImpl(
                             "basic",
-                            false,
-                            false,
-                            false,
-                            false,
-                            DokkaDefaults.documentedVisibilities
+                            includeNonPublic = false,
+                            reportUndocumented = false,
+                            skipDeprecated = false,
+                            suppress = false,
+                            documentedVisibilities = DokkaDefaults.documentedVisibilities
                         )
                     )
                 }
             }
         }
 
+        @Suppress("DEPRECATION") // for includeNonPublic
         val globalExcludesPackageIncludes = dokkaConfiguration {
             sourceSets {
                 sourceSet {
diff --git a/plugins/base/src/test/kotlin/filter/VisibilityFilterTest.kt b/plugins/base/src/test/kotlin/filter/VisibilityFilterTest.kt
index 3b333445..c89234f8 100644
--- a/plugins/base/src/test/kotlin/filter/VisibilityFilterTest.kt
+++ b/plugins/base/src/test/kotlin/filter/VisibilityFilterTest.kt
@@ -372,6 +372,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `should choose new documentedVisibilities over deprecated includeNonPublic`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -404,6 +405,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - public function with false global`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -435,6 +437,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - private function with false global`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -466,6 +469,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - private function with true global`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -497,6 +501,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `private setter with false global includeNonPublic`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -528,6 +533,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - private function with false global true package`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -569,6 +575,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - private function with true global false package`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -610,6 +617,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - private typealias should be skipped`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -636,6 +644,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - internal property from enum should be skipped`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -675,6 +684,7 @@ class VisibilityFilterTest : BaseAbstractTest() {
 
     @Test
     fun `includeNonPublic - internal property from enum`() {
+        @Suppress("DEPRECATION")
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
diff --git a/plugins/base/src/test/kotlin/linkableContent/LinkableContentTest.kt b/plugins/base/src/test/kotlin/linkableContent/LinkableContentTest.kt
index 3b0f6eef..1a4bb330 100644
--- a/plugins/base/src/test/kotlin/linkableContent/LinkableContentTest.kt
+++ b/plugins/base/src/test/kotlin/linkableContent/LinkableContentTest.kt
@@ -39,7 +39,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     dependentSourceSets = setOf(common.value.sourceSetID)
                     sourceRoots = listOf(Paths.get("$testDataDir/jvmAndJsSecondCommonMain/kotlin").toString())
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
@@ -47,7 +47,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     sourceRoots = listOf(Paths.get("$testDataDir/jsMain/kotlin").toString())
                     includes = listOf(Paths.get("$includesDir/include2.md").toString())
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
@@ -91,7 +91,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     dependentSourceSets = setOf(common.value.sourceSetID)
                     sourceRoots = listOf(Paths.get("$testDataDir/jvmAndJsSecondCommonMain/kotlin").toString())
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
@@ -105,7 +105,7 @@ class LinkableContentTest : BaseAbstractTest() {
                         )
                     )
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
@@ -165,7 +165,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     dependentSourceSets = setOf(common.value.sourceSetID)
                     sourceRoots = listOf(Paths.get("$testDataDir/jvmAndJsSecondCommonMain/kotlin").toString())
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
@@ -173,7 +173,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     sourceRoots = listOf(Paths.get("$testDataDir/jsMain/kotlin").toString())
                     samples = listOf("$testDataDir/jsMain/resources/Samples.kt")
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
@@ -192,9 +192,9 @@ class LinkableContentTest : BaseAbstractTest() {
                 Assertions.assertEquals(1, moduleChildren.size)
                 val packageChildren = moduleChildren.first().children
                 Assertions.assertEquals(2, packageChildren.size)
-                packageChildren.forEach {
-                    val name = it.name.substringBefore("Class")
-                    val classChildren = it.children
+                packageChildren.forEach { pageNode ->
+                    val name = pageNode.name.substringBefore("Class")
+                    val classChildren = pageNode.children
                     Assertions.assertEquals(2, classChildren.size)
                     val function = classChildren.find { it.name == "printWithExclamation" }
                     val text = function.cast<MemberPageNode>().content.cast<ContentGroup>().children.last()
@@ -256,7 +256,7 @@ class LinkableContentTest : BaseAbstractTest() {
                 }?.safeAs<ContentDRILink>()
 
                 Assertions.assertEquals(
-                    (sample.documentable as WithGenerics).generics.first().dri,
+                    (sample.documentables.firstOrNull() as WithGenerics).generics.first().dri,
                     returnTypeNode?.address
                 )
             }
@@ -323,7 +323,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     dependentSourceSets = setOf(common.value.sourceSetID)
                     sourceRoots = listOf(Paths.get("$testDataDir/jvmAndJsSecondCommonMain/kotlin").toString())
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
@@ -331,7 +331,7 @@ class LinkableContentTest : BaseAbstractTest() {
                     sourceRoots = listOf(Paths.get("$testDataDir/jsMain/kotlin").toString())
                     includes = listOf(Paths.get("$includesDir/include2.md").toString())
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
@@ -346,8 +346,8 @@ class LinkableContentTest : BaseAbstractTest() {
         }
 
         testFromData(configuration) {
-            documentablesMergingStage = {
-                it.documentation.entries.single {
+            documentablesMergingStage = { module ->
+                module.documentation.entries.single {
                     it.key.displayName == "jvm"
                 }.value.run {
                     Assertions.assertNotNull(dfs {
diff --git a/plugins/base/src/test/kotlin/markdown/KDocTest.kt b/plugins/base/src/test/kotlin/markdown/KDocTest.kt
index ac8efe6a..fddd41e7 100644
--- a/plugins/base/src/test/kotlin/markdown/KDocTest.kt
+++ b/plugins/base/src/test/kotlin/markdown/KDocTest.kt
@@ -26,7 +26,7 @@ abstract class KDocTest : BaseAbstractTest() {
         """.trimMargin()
 
     private fun actualDocumentationNode(modulePageNode: ModulePageNode) =
-        (modulePageNode.documentable?.children?.first() as DPackage)
+        (modulePageNode.documentables.firstOrNull()?.children?.first() as DPackage)
             .classlikes.single()
             .documentation.values.single()
 
diff --git a/plugins/base/src/test/kotlin/markdown/LinkTest.kt b/plugins/base/src/test/kotlin/markdown/LinkTest.kt
index 186fe9ee..f141bb06 100644
--- a/plugins/base/src/test/kotlin/markdown/LinkTest.kt
+++ b/plugins/base/src/test/kotlin/markdown/LinkTest.kt
@@ -74,7 +74,7 @@ class LinkTest : BaseAbstractTest() {
                 val root = rootPageNode.children.single().children.single() as ClasslikePageNode
                 val innerClass = root.children.first { it is ClasslikePageNode }
                 val foo = innerClass.children.first { it.name == "foo" } as MemberPageNode
-                val destinationDri = (root.documentable as WithGenerics).generics.first().dri.toString()
+                val destinationDri = (root.documentables.firstOrNull() as WithGenerics).generics.first().dri.toString()
 
                 assertEquals(destinationDri, "/Outer///PointingToGenericParameters(0)/")
                 assertNotNull(foo.content.dfs { it is ContentDRILink && it.address.toString() == destinationDri })
diff --git a/plugins/base/src/test/kotlin/model/CommentTest.kt b/plugins/base/src/test/kotlin/model/CommentTest.kt
index 59b1817a..6a7b2d89 100644
--- a/plugins/base/src/test/kotlin/model/CommentTest.kt
+++ b/plugins/base/src/test/kotlin/model/CommentTest.kt
@@ -72,7 +72,6 @@ class CommentTest : AbstractModelTest("/src/main/kotlin/comment/Test.kt", "comme
             |fun tst() = property
         """
         ) {
-            val p = this
             with((this / "comment" / "property").cast<DProperty>()) {
                 comments() equals ""
             }
@@ -252,85 +251,4 @@ class CommentTest : AbstractModelTest("/src/main/kotlin/comment/Test.kt", "comme
             }
         }
     }
-
-//    @Test todo
-    fun directive() {
-        inlineModelTest(
-            """
-            |/**
-            | * Summary
-            | *
-            | * @sample example1
-            | * @sample example2
-            | * @sample X.example3
-            | * @sample X.Y.example4
-            | */
-            |val property = "test"
-            |
-            |fun example1(node: String) = if (true) {
-            |    println(property)
-            |}
-            |
-            |fun example2(node: String) {
-            |    if (true) {
-            |        println(property)
-            |    }
-            |}
-            |
-            |class X {
-            |    fun example3(node: String) {
-            |        if (true) {
-            |            println(property)
-            |        }
-            |    }
-            |
-            |    class Y {
-            |        fun example4(node: String) {
-            |            if (true) {
-            |                println(property)
-            |            }
-            |        }
-            |    }
-            |}
-        """
-        ) {
-            with((this / "comment" / "property").cast<DProperty>()) {
-                this
-            }
-        }
-    }
-
-
-//    @Test fun directive() {
-//        checkSourceExistsAndVerifyModel("testdata/comments/directive.kt", defaultModelConfig) { model ->
-//            with(model.members.single().members.first()) {
-//                assertEquals("Summary", content.summary.toTestString())
-//                with (content.description) {
-//                    assertEqualsIgnoringSeparators("""
-//                        |[code lang=kotlin]
-//                        |if (true) {
-//                        |    println(property)
-//                        |}
-//                        |[/code]
-//                        |[code lang=kotlin]
-//                        |if (true) {
-//                        |    println(property)
-//                        |}
-//                        |[/code]
-//                        |[code lang=kotlin]
-//                        |if (true) {
-//                        |    println(property)
-//                        |}
-//                        |[/code]
-//                        |[code lang=kotlin]
-//                        |if (true) {
-//                        |    println(property)
-//                        |}
-//                        |[/code]
-//                        |""".trimMargin(), toTestString())
-//                }
-//            }
-//        }
-//    }
-
 }
diff --git a/plugins/base/src/test/kotlin/pageMerger/PageNodeMergerTest.kt b/plugins/base/src/test/kotlin/pageMerger/PageNodeMergerTest.kt
index 4b410f33..46b13763 100644
--- a/plugins/base/src/test/kotlin/pageMerger/PageNodeMergerTest.kt
+++ b/plugins/base/src/test/kotlin/pageMerger/PageNodeMergerTest.kt
@@ -137,14 +137,14 @@ class PageNodeMergerTest : BaseAbstractTest() {
                     analysisPlatform = "common"
                     sourceRoots = listOf("src/commonMain/kotlin/pageMerger/Test.kt")
                 }
-                val js = sourceSet {
+                sourceSet {
                     name = "js"
                     displayName = "js"
                     analysisPlatform = "js"
                     dependentSourceSets = setOf(common.value.sourceSetID)
                     sourceRoots = listOf("src/jsMain/kotlin/pageMerger/Test.kt")
                 }
-                val jvm = sourceSet {
+                sourceSet {
                     name = "jvm"
                     displayName = "jvm"
                     analysisPlatform = "jvm"
@@ -178,10 +178,10 @@ class PageNodeMergerTest : BaseAbstractTest() {
                 val jsClass = allChildren.filter { it.name == "[js]DoNotMerge" }
                 val noClass = allChildren.filter { it.name == "DoNotMerge" }
                 assertTrue(jvmClass.size == 1) { "There can be only one DoNotMerge(jvm) page" }
-                assertTrue(jvmClass.first().documentable?.sourceSets?.single()?.analysisPlatform?.key == "jvm") { "[jvm]DoNotMerge should have only jvm sources" }
+                assertTrue(jvmClass.first().documentables.firstOrNull()?.sourceSets?.single()?.analysisPlatform?.key == "jvm") { "[jvm]DoNotMerge should have only jvm sources" }
 
                 assertTrue(jsClass.size == 1) { "There can be only one DoNotMerge(js) page" }
-                assertTrue(jsClass.first().documentable?.sourceSets?.single()?.analysisPlatform?.key == "js") { "[js]DoNotMerge should have only js sources" }
+                assertTrue(jsClass.first().documentables.firstOrNull()?.sourceSets?.single()?.analysisPlatform?.key == "js") { "[js]DoNotMerge should have only js sources" }
 
                 assertTrue(noClass.isEmpty()) { "There can't be any DoNotMerge page" }
             }
diff --git a/plugins/base/src/test/kotlin/renderers/html/FormattingUtilsTest.kt b/plugins/base/src/test/kotlin/renderers/html/FormattingUtilsTest.kt
index c77a78fb..3e5ceb75 100644
--- a/plugins/base/src/test/kotlin/renderers/html/FormattingUtilsTest.kt
+++ b/plugins/base/src/test/kotlin/renderers/html/FormattingUtilsTest.kt
@@ -1,11 +1,11 @@
 package renderers.html
 
-import junit.framework.Assert.assertEquals
 import kotlinx.html.body
 import kotlinx.html.html
 import kotlinx.html.stream.createHTML
 import org.jetbrains.dokka.base.renderers.html.buildBreakableText
 import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
 
 class FormattingUtilsTest {
     @Test
diff --git a/plugins/base/src/test/kotlin/resourceLinks/ResourceLinksTest.kt b/plugins/base/src/test/kotlin/resourceLinks/ResourceLinksTest.kt
index 8a8586ee..989b82ef 100644
--- a/plugins/base/src/test/kotlin/resourceLinks/ResourceLinksTest.kt
+++ b/plugins/base/src/test/kotlin/resourceLinks/ResourceLinksTest.kt
@@ -63,7 +63,7 @@ class ResourceLinksTest : BaseAbstractTest() {
             configuration,
             pluginOverrides = listOf(TestResourcesAppenderPlugin(absoluteResources + relativeResources), writerPlugin)
         ) {
-            renderingStage = { root, context ->
+            renderingStage = { _, _ ->
                 Jsoup
                     .parse(writerPlugin.writer.contents.getValue("root/example.html"))
                     .head()
@@ -114,7 +114,7 @@ class ResourceLinksTest : BaseAbstractTest() {
             configuration,
             pluginOverrides = listOf(writerPlugin)
         ) {
-            renderingStage = { root, context ->
+            renderingStage = { _, _ ->
                 run {
                     if (isMultiModule) {
                         assertNull(writerPlugin.writer.contents["images/customImage.svg"])
@@ -179,7 +179,7 @@ class ResourceLinksTest : BaseAbstractTest() {
             configuration,
             pluginOverrides = listOf(TestResourcesAppenderPlugin(absoluteResources + relativeResources), writerPlugin)
         ) {
-            renderingStage = { root, context ->
+            renderingStage = { _, _ ->
                 run {
                     assertNull(writerPlugin.writer.contents["scripts/relativePath.js"])
                     assertNull(writerPlugin.writer.contents["styles/relativePath.js"])
diff --git a/plugins/base/src/test/kotlin/signatures/AbstractRenderingTest.kt b/plugins/base/src/test/kotlin/signatures/AbstractRenderingTest.kt
index 65ac1224..e7f408f2 100644
--- a/plugins/base/src/test/kotlin/signatures/AbstractRenderingTest.kt
+++ b/plugins/base/src/test/kotlin/signatures/AbstractRenderingTest.kt
@@ -27,14 +27,14 @@ abstract class AbstractRenderingTest : BaseAbstractTest() {
                 dependentSourceSets = setOf(common.value.sourceSetID)
                 sourceRoots = listOf(Paths.get("$testDataDir/jvmAndJsSecondCommonMain/kotlin").toString())
             }
-            val js = sourceSet {
+            sourceSet {
                 name = "js"
                 displayName = "js"
                 analysisPlatform = "js"
                 dependentSourceSets = setOf(common.value.sourceSetID, jvmAndJsSecondCommonMain.value.sourceSetID)
                 sourceRoots = listOf(Paths.get("$testDataDir/jsMain/kotlin").toString())
             }
-            val jvm = sourceSet {
+            sourceSet {
                 name = "jvm"
                 displayName = "jvm"
                 analysisPlatform = "jvm"
diff --git a/plugins/base/src/test/kotlin/transformers/MergeImplicitExpectActualDeclarationsTest.kt b/plugins/base/src/test/kotlin/transformers/MergeImplicitExpectActualDeclarationsTest.kt
index ad3b5d38..33ec2372 100644
--- a/plugins/base/src/test/kotlin/transformers/MergeImplicitExpectActualDeclarationsTest.kt
+++ b/plugins/base/src/test/kotlin/transformers/MergeImplicitExpectActualDeclarationsTest.kt
@@ -134,10 +134,10 @@ class MergeImplicitExpectActualDeclarationsTest : BaseAbstractTest() {
                 assertNotNull(classPage, "Tested class not found!")
 
                 val props = classPage.findSectionWithName("Properties").assertNotNull("Properties")
-                val prop1 = props.children.singleOrNull().assertNotNull("prop1")
+                props.children.singleOrNull().assertNotNull("prop1")
 
                 val functions = classPage.findSectionWithName("Functions").assertNotNull("Functions")
-                val method1 = functions.children.singleOrNull().assertNotNull("method1")
+                functions.children.singleOrNull().assertNotNull("method1")
             }
         }
     }
@@ -218,7 +218,7 @@ class MergeImplicitExpectActualDeclarationsTest : BaseAbstractTest() {
                 assertNotNull(classPage, "Tested class not found!")
 
                 val entries = classPage.findSectionWithName("Entries").assertNotNull("Entries")
-                val entry = entries.children.singleOrNull().assertNotNull("ENTRY")
+                entries.children.singleOrNull().assertNotNull("ENTRY")
 
                 val props = classPage.findSectionWithName("Properties").assertNotNull("Properties")
                 assertEquals(
diff --git a/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt b/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
index fd9fcc5d..79e9f548 100644
--- a/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
+++ b/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
@@ -185,48 +185,50 @@ class DefaultDescriptorToDocumentableTranslatorTest : BaseAbstractTest() {
         classlikes.zip(testSuites).forEach { (classlike, testSuites) ->
             testSuites.forEach { testSuite ->
                 when (testSuite) {
-                    is TestSuite.PropertyDoesntExist -> Assert.assertEquals(
-                        "Test for class ${classlike.name} failed",
+                    is TestSuite.PropertyDoesntExist -> assertEquals(
                         null,
-                        classlike.properties.firstOrNull { it.name == testSuite.propertyName })
+                        classlike.properties.firstOrNull { it.name == testSuite.propertyName },
+                        "Test for class ${classlike.name} failed"
+                    )
                     is TestSuite.PropertyExists -> classlike.properties.single { it.name == testSuite.propertyName }
                         .run {
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with property $name failed",
+                            assertEquals(
                                 testSuite.modifier,
-                                modifier.values.single()
+                                modifier.values.single(),
+                                "Test for class ${classlike.name} with property $name failed"
                             )
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with property $name failed",
+                            assertEquals(
                                 testSuite.visibility,
-                                visibility.values.single()
+                                visibility.values.single(),
+                                "Test for class ${classlike.name} with property $name failed"
                             )
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with property $name failed",
+                            assertEquals(
                                 testSuite.additionalModifiers,
-                                extra[AdditionalModifiers]?.content?.values?.single()
+                                extra[AdditionalModifiers]?.content?.values?.single(),
+                                "Test for class ${classlike.name} with property $name failed"
                             )
                         }
-                    is TestSuite.FunctionDoesntExist -> Assert.assertEquals(
-                        "Test for class ${classlike.name} failed",
+                    is TestSuite.FunctionDoesntExist -> assertEquals(
                         null,
-                        classlike.functions.firstOrNull { it.name == testSuite.propertyName })
+                        classlike.functions.firstOrNull { it.name == testSuite.propertyName },
+                        "Test for class ${classlike.name} failed"
+                    )
                     is TestSuite.FunctionExists -> classlike.functions.single { it.name == testSuite.propertyName }
                         .run {
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with function $name failed",
+                            assertEquals(
                                 testSuite.modifier,
-                                modifier.values.single()
+                                modifier.values.single(),
+                                "Test for class ${classlike.name} with function $name failed"
                             )
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with function $name failed",
+                            assertEquals(
                                 testSuite.visibility,
-                                visibility.values.single()
+                                visibility.values.single(),
+                                "Test for class ${classlike.name} with function $name failed"
                             )
-                            Assert.assertEquals(
-                                "Test for class ${classlike.name} with function $name failed",
+                            assertEquals(
                                 testSuite.additionalModifiers,
-                                extra[AdditionalModifiers]?.content?.values?.single()
+                                extra[AdditionalModifiers]?.content?.values?.single(),
+                                "Test for class ${classlike.name} with function $name failed"
                             )
                         }
                 }
@@ -481,6 +483,7 @@ class DefaultDescriptorToDocumentableTranslatorTest : BaseAbstractTest() {
     @Test
     fun `derived properties with only public code`() {
 
+        @Suppress("DEPRECATION") // for includeNonPublic
         val configuration = dokkaConfiguration {
             sourceSets {
                 sourceSet {
@@ -666,6 +669,7 @@ class DefaultDescriptorToDocumentableTranslatorTest : BaseAbstractTest() {
         }
     }
 
+    @Suppress("DEPRECATION") // for includeNonPublic
     val javaConfiguration = dokkaConfiguration {
         sourceSets {
             sourceSet {
diff --git a/plugins/base/src/test/kotlin/translators/DefaultPsiToDocumentableTranslatorTest.kt b/plugins/base/src/test/kotlin/translators/DefaultPsiToDocumentableTranslatorTest.kt
index 9f74e219..1213727d 100644
--- a/plugins/base/src/test/kotlin/translators/DefaultPsiToDocumentableTranslatorTest.kt
+++ b/plugins/base/src/test/kotlin/translators/DefaultPsiToDocumentableTranslatorTest.kt
@@ -14,6 +14,7 @@ import org.junit.jupiter.api.Test
 import utils.assertNotNull
 
 class DefaultPsiToDocumentableTranslatorTest : BaseAbstractTest() {
+    @Suppress("DEPRECATION") // for includeNonPublic
     val configuration = dokkaConfiguration {
         sourceSets {
             sourceSet {
diff --git a/plugins/base/src/test/kotlin/translators/JavadocInheritedDocTagsTest.kt b/plugins/base/src/test/kotlin/translators/JavadocInheritedDocTagsTest.kt
index ecde2c77..7510e541 100644
--- a/plugins/base/src/test/kotlin/translators/JavadocInheritedDocTagsTest.kt
+++ b/plugins/base/src/test/kotlin/translators/JavadocInheritedDocTagsTest.kt
@@ -12,6 +12,7 @@ import org.jetbrains.dokka.model.doc.Deprecated as DokkaDeprecatedTag
 import org.jetbrains.dokka.model.doc.Throws as DokkaThrowsTag
 
 class JavadocInheritedDocTagsTest : BaseAbstractTest() {
+    @Suppress("DEPRECATION") // for includeNonPublic
     private val configuration = dokkaConfiguration {
         sourceSets {
             sourceSet {