New J2K: Add assert statement conversion

j2k/newSrc/org/jetbrains/kotlin/j2k/ConversionsRunner.kt

@@ -46,6 +46,7 @@ object ConversionsRunner {
             +JavaMethodToKotlinFunctionConversion()
             +MainFunctionConversion()
             +LiteralConversion()
+            +AssertStatementConversion(context)
             +InnerClassConversion()
             +ModifiersConversion(context)
             +StaticsToCompanionExtractConversion()

j2k/newSrc/org/jetbrains/kotlin/j2k/JavaToJKTreeBuilder.kt

@@ -368,8 +368,10 @@ class JavaToJKTreeBuilder(var symbolProvider: JKSymbolProvider) {
                 is PsiExpressionStatement -> JKExpressionStatementImpl(with(expressionTreeMapper) { expression.toJK() })
                 is PsiReturnStatement -> JKReturnStatementImpl(with(expressionTreeMapper) { returnValue.toJK() })
                 is PsiDeclarationStatement -> JKDeclarationStatementImpl(declaredElements.toJK())
-                is PsiAssertStatement -> JKJavaAssertStatementImpl(with(expressionTreeMapper) { assertCondition.toJK() },
-                                                                   with(expressionTreeMapper) { assertDescription.toJK() })
+                is PsiAssertStatement ->
+                    JKJavaAssertStatementImpl(
+                        with(expressionTreeMapper) { assertCondition.toJK() },
+                        with(expressionTreeMapper) { assertDescription?.toJK() } ?: JKStubExpressionImpl())
                 is PsiIfStatement ->
                     if (elseElement == null)
                         JKIfStatementImpl(with(expressionTreeMapper) { condition.toJK() }, thenBranch.toJK())

j2k/newSrc/org/jetbrains/kotlin/j2k/conversions/AssertStatementConversion.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.j2k.conversions
+
+import org.jetbrains.kotlin.j2k.*
+import org.jetbrains.kotlin.j2k.tree.*
+import org.jetbrains.kotlin.j2k.tree.impl.JKExpressionStatementImpl
+import org.jetbrains.kotlin.j2k.tree.impl.JKJavaOperatorImpl
+import org.jetbrains.kotlin.j2k.tree.impl.JKLambdaExpressionImpl
+import org.jetbrains.kotlin.j2k.tree.impl.toKtToken
+
+
+class AssertStatementConversion(private val context: ConversionContext) : RecursiveApplicableConversionBase() {
+    override fun applyToElement(element: JKTreeElement): JKTreeElement {
+        if (element !is JKJavaAssertStatement) return recurse(element)
+        val messageExpression =
+            if (element.description is JKStubExpression) null
+            else JKLambdaExpressionImpl(
+                emptyList(),
+                JKExpressionStatementImpl(element::description.detached())
+            )
+        return recurse(
+            JKExpressionStatementImpl(
+                kotlinAssert(
+                    element::condition.detached(),
+                    messageExpression,
+                    context.symbolProvider
+                )
+            )
+        )
+    }
+}

j2k/newSrc/org/jetbrains/kotlin/j2k/expressions.kt

@@ -169,4 +169,22 @@ fun useExpression(
             JKExpressionListImpl(listOf(lambda))
         )
     return JKQualifiedExpressionImpl(receiver, JKKtQualifierImpl.DOT, methodCall)
-}
+}
+
+inline fun <reified Symbol : JKSymbol> symbolByName(name: String, symbolProvider: JKSymbolProvider): Symbol =
+    symbolProvider
+        .provideDirectSymbol(
+            resolveFqName(
+                ClassId.fromString(name),
+                symbolProvider.symbolsByPsi.keys.first()
+            )!!
+        ) as Symbol
+
+fun kotlinAssert(assertion: JKExpression, message: JKExpression?, symbolProvider: JKSymbolProvider) =
+    JKKtCallExpressionImpl(
+        JKUnresolvedMethod(//TODO resolve assert
+            "assert",
+            kotlinTypeByName(KotlinBuiltIns.FQ_NAMES.unit.asString(), symbolProvider)
+        ),
+        JKExpressionListImpl(listOfNotNull(assertion, message))
+    )