Added support for nullable types in is check.

js/src/com/google/dart/compiler/util/AstUtil.java

@@ -281,4 +281,12 @@ public class AstUtil {
         assert statement instanceof JsExprStmt : "Cannot extract exprssion form statement: " + statement;
         return (((JsExprStmt) statement).getExpression());
     }
+
+    public static JsBinaryOperation and(JsExpression op1, JsExpression op2) {
+        return new JsBinaryOperation(JsBinaryOperator.AND, op1, op2);
+    }
+
+    public static JsBinaryOperation or(JsExpression op1, JsExpression op2) {
+        return new JsBinaryOperation(JsBinaryOperator.OR, op1, op2);
+    }
 }

translator/src/org/jetbrains/k2js/translate/ExpressionVisitor.java

@@ -342,10 +342,9 @@ public final class ExpressionVisitor extends TranslatorVisitor<JsNode> {
                                                @NotNull TranslationContext context) {
         JsExpression receiver = translateReceiver(expression, context);
         JsNullLiteral nullLiteral = context.program().getNullLiteral();
-        JsBinaryOperation nullCheck = new JsBinaryOperation
-                (JsBinaryOperator.NEQ, receiver, nullLiteral);
         JsExpression thenExpression = translateQualifiedExpression(expression, context);
-        return new JsConditional(nullCheck, thenExpression, nullLiteral);
+        return new JsConditional(TranslationUtils.notNullCheck(receiver, context),
+                thenExpression, nullLiteral);
     }
 
     @Override

translator/src/org/jetbrains/k2js/translate/PatternTranslator.java

@@ -52,14 +52,36 @@ public final class PatternTranslator extends AbstractTranslator {
     @NotNull
     private JsExpression translateTypePattern(@NotNull JsExpression expressionToMatch,
                                               @NotNull JetTypePattern pattern) {
-        return AstUtil.newInvocation(Namer.isOperationReference(), expressionToMatch, getClassReference(pattern));
+
+        JsInvocation isCheck = AstUtil.newInvocation(Namer.isOperationReference(),
+                expressionToMatch, getClassReference(pattern));
+        if (isNullable(pattern)) {
+            return addNullCheck(expressionToMatch, isCheck);
+        }
+        return isCheck;
+    }
+
+    @NotNull
+    private JsExpression addNullCheck(@NotNull JsExpression expressionToMatch, @NotNull JsInvocation isCheck) {
+        return AstUtil.or(TranslationUtils.isNullCheck(expressionToMatch, translationContext()), isCheck);
+    }
+
+    private boolean isNullable(JetTypePattern pattern) {
+        return BindingUtils.getTypeByReference(translationContext().bindingContext(),
+                getTypeReference(pattern)).isNullable();
     }
 
     @NotNull
     private JsExpression getClassReference(@NotNull JetTypePattern pattern) {
+        JetTypeReference typeReference = getTypeReference(pattern);
+        return getClassNameReferenceForTypeReference(typeReference);
+    }
+
+    @NotNull
+    private JetTypeReference getTypeReference(@NotNull JetTypePattern pattern) {
         JetTypeReference typeReference = pattern.getTypeReference();
         assert typeReference != null : "Type pattern should contain a type reference";
-        return getClassNameReferenceForTypeReference(typeReference);
+        return typeReference;
     }
 
     @NotNull

translator/src/org/jetbrains/k2js/translate/TranslationUtils.java

@@ -0,0 +1,30 @@
+package org.jetbrains.k2js.translate;
+
+import com.google.dart.compiler.backend.js.ast.JsBinaryOperation;
+import com.google.dart.compiler.backend.js.ast.JsBinaryOperator;
+import com.google.dart.compiler.backend.js.ast.JsExpression;
+import com.google.dart.compiler.backend.js.ast.JsNullLiteral;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Talanov Pavel
+ */
+public final class TranslationUtils {
+
+    @NotNull
+    static public JsBinaryOperation notNullCheck(@NotNull JsExpression expressionToCheck,
+                                                 @NotNull TranslationContext context) {
+        JsNullLiteral nullLiteral = context.program().getNullLiteral();
+        return new JsBinaryOperation
+                (JsBinaryOperator.NEQ, expressionToCheck, nullLiteral);
+    }
+
+    @NotNull
+    static public JsBinaryOperation isNullCheck(@NotNull JsExpression expressionToCheck,
+                                                @NotNull TranslationContext context) {
+        JsNullLiteral nullLiteral = context.program().getNullLiteral();
+        return new JsBinaryOperation
+                (JsBinaryOperator.REF_EQ, expressionToCheck, nullLiteral);
+    }
+
+}

translator/src/org/jetbrains/k2js/translate/WhenTranslator.java

@@ -103,7 +103,6 @@ public class WhenTranslator extends AbstractTranslator {
         return Translation.translateAsStatement(expressionToExecute, translationContext());
     }
 
-    //TODO: ask what these conditions mean
     @NotNull
     private JsExpression translateConditions(@NotNull JetWhenEntry entry) {
         List<JsExpression> conditions = new ArrayList<JsExpression>();
@@ -127,11 +126,10 @@ public class WhenTranslator extends AbstractTranslator {
     @NotNull
     private JsExpression addCaseCondition(@Nullable JsExpression current, @NotNull JsExpression condition) {
         if (current == null) {
-            current = condition;
+            return condition;
         } else {
-            current = new JsBinaryOperation(JsBinaryOperator.OR, current, condition);
+            return AstUtil.or(current, condition);
         }
-        return current;
     }
 
 

translator/test/org/jetbrains/k2js/test/PatternMatchingTest.java

@@ -49,4 +49,9 @@ public final class PatternMatchingTest extends IncludeLibraryTest {
         testFunctionOutput("multipleCases.kt", "foo", "box", 2.0);
     }
 
+    @Test
+    public void matchNullableType() throws Exception {
+        testFooBoxIsTrue("matchNullableType.kt");
+    }
+
 }

translator/testFiles/patternMatching/cases/matchNullableType.kt

@@ -0,0 +1,13 @@
+namespace foo
+
+class A() {
+
+}
+
+fun box() : Boolean {
+  var a = null : A?
+  when(a) {
+    is A? => return true
+    else =>  return false
+  }
+}