KT-5673: always write val property to backing field

js/js.translator/src/org/jetbrains/k2js/translate/operation/AssignmentTranslator.java

@@ -19,17 +19,23 @@ package org.jetbrains.k2js.translate.operation;
 import com.google.dart.compiler.backend.js.ast.JsBlock;
 import com.google.dart.compiler.backend.js.ast.JsExpression;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.descriptors.PropertyDescriptor;
 import org.jetbrains.jet.lang.psi.JetBinaryExpression;
 import org.jetbrains.jet.lang.psi.JetExpression;
+import org.jetbrains.jet.lang.psi.JetSimpleNameExpression;
 import org.jetbrains.jet.lang.types.expressions.OperatorConventions;
 import org.jetbrains.jet.lexer.JetToken;
 import org.jetbrains.k2js.translate.context.TranslationContext;
 import org.jetbrains.k2js.translate.general.AbstractTranslator;
 import org.jetbrains.k2js.translate.reference.AccessTranslationUtils;
 import org.jetbrains.k2js.translate.reference.AccessTranslator;
+import org.jetbrains.k2js.translate.reference.BackingFieldAccessTranslator;
 
+import static org.jetbrains.k2js.translate.utils.BindingUtils.getDescriptorForReferenceExpression;
 import static org.jetbrains.k2js.translate.utils.BindingUtils.isVariableReassignment;
 import static org.jetbrains.k2js.translate.utils.PsiUtils.getOperationToken;
+import static org.jetbrains.k2js.translate.utils.PsiUtils.getSimpleName;
 import static org.jetbrains.k2js.translate.utils.PsiUtils.isAssignment;
 import static org.jetbrains.k2js.translate.utils.TranslationUtils.hasCorrespondingFunctionIntrinsic;
 import static org.jetbrains.k2js.translate.utils.TranslationUtils.translateRightExpression;
@@ -69,7 +75,28 @@ public abstract class AssignmentTranslator extends AbstractTranslator {
         JsBlock rightBlock = new JsBlock();
         this.right = translateRightExpression(context, expression, rightBlock);
 
-        this.accessTranslator = AccessTranslationUtils.getAccessTranslator(left, context(), !rightBlock.isEmpty());
+        if (isValProperty(left, context)) {
+            JetSimpleNameExpression simpleName = getSimpleName(left);
+            assert simpleName != null;
+            this.accessTranslator = BackingFieldAccessTranslator.newInstance(simpleName, context);
+        } else {
+            this.accessTranslator = AccessTranslationUtils.getAccessTranslator(left, context(), !rightBlock.isEmpty());
+        }
+
         context.addStatementsToCurrentBlockFrom(rightBlock);
     }
+
+    private static boolean isValProperty(
+            @NotNull JetExpression expression,
+            @NotNull TranslationContext context
+    ) {
+        JetSimpleNameExpression simpleNameExpression = getSimpleName(expression);
+
+        if (simpleNameExpression != null) {
+            DeclarationDescriptor descriptor = getDescriptorForReferenceExpression(context.bindingContext(), simpleNameExpression);
+            return descriptor instanceof PropertyDescriptor && !((PropertyDescriptor) descriptor).isVar();
+        }
+
+        return false;
+    }
 }

js/js.translator/src/org/jetbrains/k2js/translate/reference/BackingFieldAccessTranslator.java

@@ -20,7 +20,6 @@ import com.google.dart.compiler.backend.js.ast.JsExpression;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.PropertyDescriptor;
-import org.jetbrains.jet.lang.psi.JetPsiUtil;
 import org.jetbrains.jet.lang.psi.JetSimpleNameExpression;
 import org.jetbrains.k2js.translate.context.TemporaryVariable;
 import org.jetbrains.k2js.translate.context.TranslationContext;
@@ -39,9 +38,8 @@ public final class BackingFieldAccessTranslator extends AbstractTranslator imple
     private final PropertyDescriptor descriptor;
 
     /*package*/
-    static BackingFieldAccessTranslator newInstance(@NotNull JetSimpleNameExpression expression,
+    public static BackingFieldAccessTranslator newInstance(@NotNull JetSimpleNameExpression expression,
                                                     @NotNull TranslationContext context) {
-        assert JetPsiUtil.isBackingFieldReference(expression);
         DeclarationDescriptor referencedProperty = getDescriptorForReferenceExpression(context.bindingContext(), expression);
         assert referencedProperty instanceof PropertyDescriptor;
         return new BackingFieldAccessTranslator((PropertyDescriptor) referencedProperty, context);

js/js.translator/src/org/jetbrains/k2js/translate/utils/PsiUtils.java

@@ -31,6 +31,19 @@ public final class PsiUtils {
     private PsiUtils() {
     }
 
+    @Nullable
+    public static JetSimpleNameExpression getSimpleName(@NotNull JetExpression expression) {
+        if (expression instanceof JetSimpleNameExpression) {
+            return (JetSimpleNameExpression) expression;
+        }
+
+        if (expression instanceof JetQualifiedExpression) {
+            return getSelectorAsSimpleName((JetQualifiedExpression) expression);
+        }
+
+        return null;
+    }
+
     @Nullable
     public static JetSimpleNameExpression getSelectorAsSimpleName(@NotNull JetQualifiedExpression expression) {
         JetExpression selectorExpression = getSelector(expression);