diff --git a/platform/script-debugger/backend/src/org/jetbrains/concurrency/AsyncPromise.java b/platform/script-debugger/backend/src/org/jetbrains/concurrency/AsyncPromise.java
index edfb854d96d5..a9df79ecf0d1 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/concurrency/AsyncPromise.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/concurrency/AsyncPromise.java
@@ -1,14 +1,18 @@
 package org.jetbrains.concurrency;
 
+import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.Getter;
 import com.intellij.util.Consumer;
 import com.intellij.util.Function;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
 
 public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
+  private static final Logger LOG = Logger.getInstance(AsyncPromise.class);
+
   private volatile Consumer<T> done;
   private volatile Consumer<Throwable> rejected;
 
@@ -25,6 +29,10 @@ public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
   @NotNull
   @Override
   public Promise<T> done(@NotNull Consumer<T> done) {
+    if (isObsolete(done)) {
+      return this;
+    }
+
     switch (state) {
       case PENDING:
         break;
@@ -84,7 +92,9 @@ public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
 
       if (list != null) {
         for (Consumer<T> consumer : list) {
-          consumer.consume(t);
+          if (!isObsolete(consumer)) {
+            consumer.consume(t);
+          }
         }
       }
     }
@@ -213,6 +223,7 @@ public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
     return promise;
   }
 
+  @Override
   @NotNull
   public Promise<T> processed(@NotNull final AsyncPromise<T> fulfilled) {
     switch (state) {
@@ -275,11 +286,15 @@ public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
 
     Consumer<T> done = this.done;
     clearHandlers();
-    if (done != null) {
+    if (done != null && !isObsolete(done)) {
       done.consume(result);
     }
   }
 
+  static boolean isObsolete(@Nullable Consumer<?> done) {
+    return done instanceof ObsolescentConsumer && ((ObsolescentConsumer)done).isObsolete();
+  }
+
   public void setError(@NotNull Throwable error) {
     if (state != State.PENDING) {
       return;
@@ -293,6 +308,9 @@ public class AsyncPromise<T> extends Promise<T> implements Getter<T> {
     if (rejected != null) {
       rejected.consume(error);
     }
+    else if (!(error instanceof MessageError)) {
+      LOG.error(error);
+    }
   }
 
   private void clearHandlers() {
diff --git a/platform/script-debugger/backend/src/org/jetbrains/concurrency/DonePromise.java b/platform/script-debugger/backend/src/org/jetbrains/concurrency/DonePromise.java
index 5a689594c947..3653bd6f634f 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/concurrency/DonePromise.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/concurrency/DonePromise.java
@@ -15,7 +15,9 @@ class DonePromise<T> extends Promise<T> implements Getter<T> {
   @NotNull
   @Override
   public Promise<T> done(@NotNull Consumer<T> done) {
-    done.consume(result);
+    if (!AsyncPromise.isObsolete(done)) {
+      done.consume(result);
+    }
     return this;
   }
 
@@ -26,21 +28,26 @@ class DonePromise<T> extends Promise<T> implements Getter<T> {
     return this;
   }
 
+  @Override
+  public void processed(@NotNull Consumer<T> processed) {
+    done(processed);
+  }
+
   @NotNull
   @Override
   public Promise<T> rejected(@NotNull Consumer<Throwable> rejected) {
     return this;
   }
 
-  @Override
-  public void processed(@NotNull Consumer<T> processed) {
-    processed.consume(result);
-  }
-
   @NotNull
   @Override
   public <SUB_RESULT> Promise<SUB_RESULT> then(@NotNull Function<T, SUB_RESULT> done) {
-    return Promise.resolve(done.fun(result));
+    if (done instanceof ObsolescentFunction && ((ObsolescentFunction)done).isObsolete()) {
+      return Promise.reject("obsolete");
+    }
+    else {
+      return Promise.resolve(done.fun(result));
+    }
   }
 
   @NotNull
diff --git a/platform/script-debugger/backend/src/org/jetbrains/concurrency/ObsolescentConsumer.java b/platform/script-debugger/backend/src/org/jetbrains/concurrency/ObsolescentConsumer.java
new file mode 100644
index 000000000000..51442709a714
--- /dev/null
+++ b/platform/script-debugger/backend/src/org/jetbrains/concurrency/ObsolescentConsumer.java
@@ -0,0 +1,7 @@
+package org.jetbrains.concurrency;
+
+import com.intellij.util.Consumer;
+
+public interface ObsolescentConsumer<T> extends Consumer<T> {
+  boolean isObsolete();
+}
diff --git a/platform/script-debugger/backend/src/org/jetbrains/concurrency/PromiseManager.java b/platform/script-debugger/backend/src/org/jetbrains/concurrency/PromiseManager.java
index 5fc5a36df047..f6821f9e074e 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/concurrency/PromiseManager.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/concurrency/PromiseManager.java
@@ -22,7 +22,7 @@ public abstract class PromiseManager<HOST, VALUE> {
     return true;
   }
 
-  public abstract Promise<VALUE> load(@NotNull HOST host, Promise<VALUE> promise);
+  public abstract Promise<VALUE> load(@NotNull HOST host);
 
   public final void reset(HOST host) {
     fieldUpdater.set(host, null);
@@ -52,6 +52,7 @@ public abstract class PromiseManager<HOST, VALUE> {
     return getOrCreateAsyncResult(host, checkFreshness, true);
   }
 
+  @NotNull
   private Promise<VALUE> getOrCreateAsyncResult(HOST host, boolean checkFreshness, boolean load) {
     Promise<VALUE> promise = fieldUpdater.get(host);
     if (promise == null) {
@@ -89,14 +90,14 @@ public abstract class PromiseManager<HOST, VALUE> {
     return getPromise(host, load, promise);
   }
 
+  @NotNull
   private Promise<VALUE> getPromise(HOST host, boolean load, Promise<VALUE> promise) {
-    if (load) {
-      Promise<VALUE> effectivePromise = load(host, promise);
-      if (effectivePromise != promise) {
-        ((AsyncPromise<VALUE>)effectivePromise).notify((AsyncPromise<VALUE>)promise);
-      }
-      return effectivePromise;
+    if (!load) {
+      return promise;
     }
-    return promise;
+
+    Promise<VALUE> effectivePromise = load(host);
+    ((AsyncPromise<VALUE>)effectivePromise).notify((AsyncPromise<VALUE>)promise);
+    return effectivePromise;
   }
 }
\ No newline at end of file
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/DeclarativeScope.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/DeclarativeScope.java
index 2aae26df93fb..fa7f76383f86 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/DeclarativeScope.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/DeclarativeScope.java
@@ -20,7 +20,7 @@ public abstract class DeclarativeScope<VALUE_LOADER extends ValueManager> extend
 
       @NotNull
       @Override
-      public Promise<List<Variable>> load(@NotNull DeclarativeScope host, @NotNull Promise<List<Variable>> promise) {
+      public Promise<List<Variable>> load(@NotNull DeclarativeScope host) {
         //noinspection unchecked
         return host.loadVariables();
       }
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContext.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContext.java
index 2126775e07a4..0fba1f42eb89 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContext.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContext.java
@@ -11,18 +11,20 @@ import java.util.Map;
  * of suspended process, but may also be detached from any stack frame
  */
 public interface EvaluateContext {
-
   /**
    * Evaluates an arbitrary {@code expression} in the particular context.
    * Previously loaded {@link org.jetbrains.debugger.values.ObjectValue}s can be addressed from the expression if listed in
    * additionalContext parameter.
    */
   @NotNull
-  Promise<EvaluateResult> evaluate(@NotNull String expression, @Nullable Map<String, EvaluateContextAdditionalParameter> additionalContext);
+  Promise<EvaluateResult> evaluate(@NotNull String expression, @Nullable Map<String, EvaluateContextAdditionalParameter> additionalContext, boolean enableBreak);
 
   @NotNull
   Promise<EvaluateResult> evaluate(@NotNull String expression);
 
+  @NotNull
+  Promise<EvaluateResult> evaluate(@NotNull String expression, boolean enableBreak);
+
   /**
    * optional to implement, some protocols, WIP for example, require you to release remote objects
    */
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContextBase.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContextBase.java
index d30b3ce35f10..812f24d5d0f5 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContextBase.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/EvaluateContextBase.java
@@ -17,7 +17,13 @@ public abstract class EvaluateContextBase<VALUE_MANAGER extends ValueManager> im
   @NotNull
   @Override
   public Promise<EvaluateResult> evaluate(@NotNull String expression) {
-    return evaluate(expression, null);
+    return evaluate(expression, null, false);
+  }
+
+  @NotNull
+  @Override
+  public Promise<EvaluateResult> evaluate(@NotNull String expression, boolean enableBreak) {
+    return evaluate(expression, null, true);
   }
 
   @NotNull
@@ -32,7 +38,7 @@ public abstract class EvaluateContextBase<VALUE_MANAGER extends ValueManager> im
 
   @NotNull
   @Override
-  public abstract Promise<EvaluateResult> evaluate(@NotNull String expression, @Nullable Map<String, EvaluateContextAdditionalParameter> additionalContext);
+  public abstract Promise<EvaluateResult> evaluate(@NotNull String expression, @Nullable Map<String, EvaluateContextAdditionalParameter> additionalContext, boolean enableBreak);
 
   @NotNull
   public final VALUE_MANAGER getValueManager() {
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/ScriptManagerBase.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/ScriptManagerBase.java
index 5b1de9c9ea2f..9b3a225e4272 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/ScriptManagerBase.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/ScriptManagerBase.java
@@ -13,7 +13,7 @@ public abstract class ScriptManagerBase<SCRIPT extends ScriptBase> implements Sc
   @SuppressWarnings("unchecked")
   private final PromiseManager<ScriptBase, String> scriptSourceLoader = new PromiseManager<ScriptBase, String>(ScriptBase.class) {
     @Override
-    public Promise<String> load(@NotNull ScriptBase script, @NotNull Promise<String> result) {
+    public Promise<String> load(@NotNull ScriptBase script) {
       //noinspection unchecked
       return loadScriptSource((SCRIPT)script);
     }
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/ValueModifierUtil.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/ValueModifierUtil.java
index 9a3988e8f072..87a3fea900e2 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/ValueModifierUtil.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/ValueModifierUtil.java
@@ -31,13 +31,14 @@ public final class ValueModifierUtil {
                                            @NotNull String selfName) {
     StringBuilder builder = new StringBuilder(selfName);
     appendName(builder, variable.getName(), false);
-    return evaluateContext.evaluate(builder.toString(), Collections.singletonMap(selfName, host)).then(new Function<EvaluateResult, Value>() {
-      @Override
-      public Value fun(EvaluateResult result) {
-        variable.setValue(result.value);
-        return result.value;
-      }
-    });
+    return evaluateContext.evaluate(builder.toString(), Collections.singletonMap(selfName, host), false)
+      .then(new Function<EvaluateResult, Value>() {
+        @Override
+        public Value fun(EvaluateResult result) {
+          variable.setValue(result.value);
+          return result.value;
+        }
+      });
   }
 
   public static String propertyNamesToString(List<String> list, boolean quotedAware) {
diff --git a/platform/script-debugger/backend/src/org/jetbrains/debugger/values/ObjectValueBase.java b/platform/script-debugger/backend/src/org/jetbrains/debugger/values/ObjectValueBase.java
index 9b349af82f70..635266cf9bb8 100644
--- a/platform/script-debugger/backend/src/org/jetbrains/debugger/values/ObjectValueBase.java
+++ b/platform/script-debugger/backend/src/org/jetbrains/debugger/values/ObjectValueBase.java
@@ -20,7 +20,7 @@ public abstract class ObjectValueBase<VALUE_LOADER extends ValueManager> extends
       }
 
       @Override
-      public Promise<List<Variable>> load(@NotNull ObjectValueBase host, @NotNull Promise<List<Variable>> promise) {
+      public Promise<List<Variable>> load(@NotNull ObjectValueBase host) {
         if (host.valueManager.isObsolete()) {
           return ValueManager.reject();
         }
diff --git a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/FunctionScopesValueGroup.java b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/FunctionScopesValueGroup.java
index 5890209f75e0..dc4d12b51705 100644
--- a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/FunctionScopesValueGroup.java
+++ b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/FunctionScopesValueGroup.java
@@ -1,11 +1,13 @@
 package org.jetbrains.debugger;
 
-import com.intellij.util.PairConsumer;
+import com.intellij.util.Consumer;
 import com.intellij.xdebugger.frame.XCompositeNode;
 import com.intellij.xdebugger.frame.XValueChildrenList;
 import com.intellij.xdebugger.frame.XValueGroup;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.concurrency.Promise;
 import org.jetbrains.debugger.values.FunctionValue;
+import org.jetbrains.rpc.CommandProcessor;
 
 import java.util.Arrays;
 
@@ -21,12 +23,13 @@ class FunctionScopesValueGroup extends XValueGroup {
   }
 
   @Override
-  public void computeChildren(@NotNull XCompositeNode node) {
+  public void computeChildren(@NotNull final XCompositeNode node) {
     node.setAlreadySorted(true);
 
-    ObsolescentAsyncResults.consume(value.resolve(), node, new PairConsumer<FunctionValue, XCompositeNode>() {
+    value.resolve()
+      .done(new ValueNodeConsumer<FunctionValue>(node) {
       @Override
-      public void consume(FunctionValue value, XCompositeNode node) {
+      public void consume(FunctionValue value) {
         Scope[] scopes = value.getScopes();
         if (scopes == null || scopes.length == 0) {
           node.addChildren(XValueChildrenList.EMPTY, true);
@@ -35,6 +38,15 @@ class FunctionScopesValueGroup extends XValueGroup {
           ScopeVariablesGroup.createAndAddScopeList(node, Arrays.asList(scopes), variableContext, null);
         }
       }
+    })
+    .rejected(new Consumer<Throwable>() {
+      @Override
+      public void consume(Throwable error) {
+        if (!(error instanceof Promise.MessageError)) {
+          CommandProcessor.LOG.error(error);
+        }
+        node.setErrorMessage(error.getMessage());
+      }
     });
   }
 }
\ No newline at end of file
diff --git a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ObsolescentAsyncResults.java b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ObsolescentAsyncResults.java
deleted file mode 100644
index e9f9b64a5662..000000000000
--- a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ObsolescentAsyncResults.java
+++ /dev/null
@@ -1,55 +0,0 @@
-package org.jetbrains.debugger;
-
-import com.intellij.openapi.util.AsyncResult;
-import com.intellij.util.Consumer;
-import com.intellij.util.PairConsumer;
-import com.intellij.xdebugger.Obsolescent;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.concurrency.Promise;
-
-public final class ObsolescentAsyncResults {
-  @NotNull
-  public static <T> AsyncResult<T> consume(@NotNull final AsyncResult<T> result,
-                                           @NotNull final Obsolescent obsolescent,
-                                           @NotNull final Consumer<T> consumer) {
-    result.doWhenDone(new Runnable() {
-      @Override
-      public void run() {
-        if (!obsolescent.isObsolete()) {
-          consumer.consume(result.getResult());
-        }
-      }
-    });
-    return result;
-  }
-
-  @NotNull
-  public static <O extends Obsolescent, T> AsyncResult<T> consume(@NotNull final AsyncResult<T> result,
-                                                                  @NotNull final O obsolescent,
-                                                                  @NotNull final PairConsumer<T, O> consumer) {
-    result.doWhenDone(new Runnable() {
-      @Override
-      public void run() {
-        if (!obsolescent.isObsolete()) {
-          consumer.consume(result.getResult(), obsolescent);
-        }
-      }
-    });
-    return result;
-  }
-
-  @NotNull
-  public static <O extends Obsolescent, T> Promise<T> consume(@NotNull final Promise<T> promise,
-                                                        @NotNull final O obsolescent,
-                                                        @NotNull final PairConsumer<T, O> consumer) {
-    promise.done(new Consumer<T>() {
-      @Override
-      public void consume(T result) {
-        if (!obsolescent.isObsolete()) {
-          consumer.consume(result, obsolescent);
-        }
-      }
-    });
-    return promise;
-  }
-}
\ No newline at end of file
diff --git a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ValueNodeConsumer.java b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ValueNodeConsumer.java
new file mode 100644
index 000000000000..481ed13c02a3
--- /dev/null
+++ b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/ValueNodeConsumer.java
@@ -0,0 +1,18 @@
+package org.jetbrains.debugger;
+
+import com.intellij.xdebugger.Obsolescent;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.concurrency.ObsolescentConsumer;
+
+public abstract class ValueNodeConsumer<T> implements ObsolescentConsumer<T> {
+  private final Obsolescent node;
+
+  protected ValueNodeConsumer(@NotNull Obsolescent node) {
+    this.node = node;
+  }
+
+  @Override
+  public final boolean isObsolete() {
+    return node.isObsolete();
+  }
+}
diff --git a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/VariableView.java b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/VariableView.java
index 1b0a75679e28..9a7bc2fcb864 100644
--- a/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/VariableView.java
+++ b/platform/script-debugger/debugger-ui/src/org/jetbrains/debugger/VariableView.java
@@ -8,7 +8,6 @@ import com.intellij.pom.Navigatable;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiReference;
 import com.intellij.util.Consumer;
-import com.intellij.util.PairConsumer;
 import com.intellij.util.SmartList;
 import com.intellij.util.ThreeState;
 import com.intellij.xdebugger.XSourcePositionWrapper;
@@ -99,7 +98,7 @@ public final class VariableView extends XNamedValue implements VariableContext {
       node.setPresentation(icon, null, valueString, true);
     }
     else {
-      context.getEvaluateContext().evaluate("a.length", Collections.<String, EvaluateContextAdditionalParameter>singletonMap("a", value))
+      context.getEvaluateContext().evaluate("a.length", Collections.<String, EvaluateContextAdditionalParameter>singletonMap("a", value), false)
         .done(new Consumer<EvaluateResult>() {
           @Override
           public void consume(EvaluateResult result) {
@@ -383,31 +382,32 @@ public final class VariableView extends XNamedValue implements VariableContext {
   }
 
   @NotNull
-  private Promise<List<Variable>> computeNamedProperties(@NotNull final ObjectValue value, @NotNull XCompositeNode node, final boolean isLastChildren) {
-    return ObsolescentAsyncResults.consume(value.getProperties(), node, new PairConsumer<List<Variable>, XCompositeNode>() {
-      @Override
-      public void consume(List<Variable> variables, XCompositeNode node) {
-        if (value.getType() == ValueType.ARRAY && !(value instanceof ArrayValue)) {
-          computeArrayRanges(variables, node);
-          return;
-        }
+  private Promise<List<Variable>> computeNamedProperties(@NotNull final ObjectValue value, @NotNull final XCompositeNode node, final boolean isLastChildren) {
+    return value.getProperties()
+      .done(new ValueNodeConsumer<List<Variable>>(node) {
+        @Override
+        public void consume(List<Variable> variables) {
+          if (value.getType() == ValueType.ARRAY && !(value instanceof ArrayValue)) {
+            computeArrayRanges(variables, node);
+            return;
+          }
 
-        FunctionValue functionValue = value instanceof FunctionValue ? (FunctionValue)value : null;
-        if (functionValue != null && functionValue.hasScopes() == ThreeState.NO) {
-          functionValue = null;
-        }
+          FunctionValue functionValue = value instanceof FunctionValue ? (FunctionValue)value : null;
+          if (functionValue != null && functionValue.hasScopes() == ThreeState.NO) {
+            functionValue = null;
+          }
 
-        remainingChildren = Variables.sortFilterAndAddValueList(variables, node, VariableView.this, XCompositeNode.MAX_CHILDREN_TO_SHOW, isLastChildren && functionValue == null);
-        if (remainingChildren != null) {
-          remainingChildrenOffset = XCompositeNode.MAX_CHILDREN_TO_SHOW;
-        }
+          remainingChildren = Variables.sortFilterAndAddValueList(variables, node, VariableView.this, XCompositeNode.MAX_CHILDREN_TO_SHOW, isLastChildren && functionValue == null);
+          if (remainingChildren != null) {
+            remainingChildrenOffset = XCompositeNode.MAX_CHILDREN_TO_SHOW;
+          }
 
-        if (functionValue != null) {
-          // we pass context as variable context instead of this variable value - we cannot watch function scopes variables, so, this variable name doesn't matter
-          node.addChildren(XValueChildrenList.bottomGroup(new FunctionScopesValueGroup(functionValue, context)), isLastChildren);
+          if (functionValue != null) {
+            // we pass context as variable context instead of this variable value - we cannot watch function scopes variables, so, this variable name doesn't matter
+            node.addChildren(XValueChildrenList.bottomGroup(new FunctionScopesValueGroup(functionValue, context)), isLastChildren);
+          }
         }
-      }
-    });
+      });
   }
 
   private void computeArrayRanges(@NotNull List<Variable> properties, @NotNull XCompositeNode node) {
diff --git a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/io/JsonReaderEx.java b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/io/JsonReaderEx.java
index 806bfdde7deb..a8dd68264ab6 100644
--- a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/io/JsonReaderEx.java
+++ b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/io/JsonReaderEx.java
@@ -228,7 +228,7 @@ public final class JsonReaderEx implements Closeable {
    * Consumes the next token from the JSON stream and asserts that it is the
    * beginning of a new object.
    */
-  public void beginObject() {
+  public JsonReaderEx beginObject() {
     int p = peeked;
     if (p == PEEKED_NONE) {
       p = doPeek();
@@ -240,6 +240,7 @@ public final class JsonReaderEx implements Closeable {
     else {
       throw createParseError("Expected BEGIN_OBJECT but was " + peek());
     }
+    return this;
   }
 
   /**
diff --git a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonNullable.java b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonNullable.java
deleted file mode 100644
index 8e88ab4eb2b4..000000000000
--- a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonNullable.java
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.jetbrains.jsonProtocol;
-
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * For field-reading method specifies its type as {@code nullable}; it means
- * that JSON structure may have null value for a corresponding property.
- */
-@Target({ElementType.METHOD})
-@Retention(RetentionPolicy.RUNTIME)
-public @interface JsonNullable {
-}
diff --git a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonReaders.java b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonReaders.java
index 056e4dc6b78f..757536c9d018 100644
--- a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonReaders.java
+++ b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/JsonReaders.java
@@ -24,76 +24,19 @@ public final class JsonReaders {
     }
   }
 
-  public static String readString(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
-    return reader.nextString();
-  }
-
   public static String readRawString(JsonReaderEx reader) {
     return reader.nextString(true);
   }
 
   public static Object readRawStringOrMap(JsonReaderEx reader) {
     if (reader.peek() == JsonToken.BEGIN_OBJECT) {
-      return readMap(reader, null);
+      return readMap(reader);
     }
     else {
       return reader.nextString(true);
     }
   }
 
-  public static String readNullableString(JsonReaderEx reader) {
-    if (reader.peek() == JsonToken.NULL) {
-      reader.skipValue();
-      return null;
-    }
-    return reader.nextString();
-  }
-
-  public static boolean readBoolean(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
-    return reader.nextBoolean();
-  }
-
-  public static boolean readNullableBoolean(JsonReaderEx reader) {
-    if (reader.peek() == JsonToken.NULL) {
-      reader.skipValue();
-      return false;
-    }
-    return reader.nextBoolean();
-  }
-
-  public static int readInt(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
-    return reader.nextInt();
-  }
-
-  public static int readNullableInt(JsonReaderEx reader) {
-    if (reader.peek() == JsonToken.NULL) {
-      reader.skipValue();
-      return -1;
-    }
-    return reader.nextInt();
-  }
-
-  public static long readLong(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
-    return reader.nextLong();
-  }
-
-  public static double readDouble(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
-    return reader.nextDouble();
-  }
-
-  public static long readNullableLong(JsonReaderEx reader) {
-    if (reader.peek() == JsonToken.NULL) {
-      reader.skipValue();
-      return -1;
-    }
-    return reader.nextLong();
-  }
-
   public static <T extends Enum<T>> T readEnum(JsonReaderEx reader, String fieldName, Class<T> enumClass) {
     checkIsNull(reader, fieldName);
     try {
@@ -133,7 +76,7 @@ public final class JsonReaders {
     return convertRawEnumName(reader.nextString());
   }
 
-  public static <T extends Enum<T>> T readNullableEnum(JsonReaderEx reader, Class<T> enumClass) {
+  public static <T extends Enum<T>> T readEnum(JsonReaderEx reader, Class<T> enumClass) {
     if (reader.peek() == JsonToken.NULL) {
       reader.skipValue();
       return null;
@@ -141,26 +84,16 @@ public final class JsonReaders {
     return Enum.valueOf(enumClass, readEnumName(reader));
   }
 
-  public static <T> List<T> readObjectArray(JsonReaderEx reader, String fieldName, ObjectFactory<T> factory, boolean nullable) {
+  public static <T> List<T> readObjectArray(JsonReaderEx reader, ObjectFactory<T> factory) {
     if (reader.peek() == JsonToken.NULL) {
-      if (nullable) {
-        reader.skipValue();
-        return null;
-      }
-      else {
-        checkIsNull(reader, fieldName);
-      }
+      reader.skipValue();
+      return null;
     }
 
     reader.beginArray();
     if (!reader.hasNext()) {
       reader.endArray();
-      if (nullable) {
-        return null;
-      }
-      else {
-        return Collections.emptyList();
-      }
+      return Collections.emptyList();
     }
 
     List<T> result = new ArrayList<T>();
@@ -172,8 +105,7 @@ public final class JsonReaders {
     return result;
   }
 
-  public static Map<?, ?> readMap(JsonReaderEx reader, String fieldName) {
-    checkIsNull(reader, fieldName);
+  public static Map<?, ?> readMap(JsonReaderEx reader) {
     reader.beginObject();
     if (!reader.hasNext()) {
       reader.endObject();
@@ -321,10 +253,6 @@ public final class JsonReaders {
     return result;
   }
 
-  public static JsonReaderEx createReader(CharSequence string) {
-    return new JsonReaderEx(string);
-  }
-
   public static boolean findBooleanField(String name, JsonReaderEx reader) {
     reader.beginObject();
     while (reader.hasNext()) {
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ArrayReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ArrayReader.java
index 687652b92e8b..ea679c00aefa 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ArrayReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ArrayReader.java
@@ -4,8 +4,8 @@ class ArrayReader extends ValueReader {
   private final ValueReader componentParser;
   private final boolean isList;
 
-  ArrayReader(ValueReader componentParser, boolean isList, boolean nullable) {
-    super(nullable);
+  ArrayReader(ValueReader componentParser, boolean isList) {
+    super();
 
     this.componentParser = componentParser;
     this.isList = isList;
@@ -31,13 +31,10 @@ class ArrayReader extends ValueReader {
 
   @Override
   void writeReadCode(ClassScope scope, boolean subtyping, String fieldName, TextOutput out) {
-    componentParser.writeArrayReadCode(scope, subtyping, isNullable(), fieldName, out);
+    componentParser.writeArrayReadCode(scope, subtyping, out);
   }
 
   @Override
-  void writeArrayReadCode(ClassScope scope,
-                          boolean subtyping,
-                          boolean nullable,
-                          String fieldName, TextOutput out) {
+  void writeArrayReadCode(ClassScope scope, boolean subtyping, TextOutput out) {
   }
 }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/EnumReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/EnumReader.java
index c17574dd3eac..271831ae5c68 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/EnumReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/EnumReader.java
@@ -5,14 +5,14 @@
 package org.jetbrains.protocolReader;
 
 class EnumReader<T extends Enum<T>> extends ValueReader {
-  public static <T extends Enum<T>> EnumReader<T> create(Class<T> enumTypeClass, boolean isNullable) {
-    return new EnumReader<>(enumTypeClass, isNullable);
+  public static <T extends Enum<T>> EnumReader<T> create(Class<T> enumTypeClass) {
+    return new EnumReader<>(enumTypeClass);
   }
 
   private final Class<T> enumClass;
 
-  private EnumReader(Class<T> enumClass, boolean nullable) {
-    super(nullable);
+  private EnumReader(Class<T> enumClass) {
+    super();
     this.enumClass = enumClass;
   }
 
@@ -23,15 +23,14 @@ class EnumReader<T extends Enum<T>> extends ValueReader {
 
   @Override
   void writeReadCode(ClassScope scope, boolean subtyping, String fieldName, TextOutput out) {
-    beginReadCall("Enum", subtyping, out, fieldName);
+    beginReadCall("Enum", subtyping, out);
     out.comma().append(enumClass.getCanonicalName()).append(".class").append(')');
   }
 
   @Override
   void writeArrayReadCode(ClassScope scope,
                           boolean subtyping,
-                          boolean nullable,
-                          String fieldName, TextOutput out) {
+                          TextOutput out) {
     throw new UnsupportedOperationException();
   }
 }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/FieldProcessor.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/FieldProcessor.java
index 1acdee3f8f8f..bd4f2b62852b 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/FieldProcessor.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/FieldProcessor.java
@@ -2,11 +2,11 @@ package org.jetbrains.protocolReader;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jsonProtocol.JsonField;
-import org.jetbrains.jsonProtocol.JsonNullable;
 import org.jetbrains.jsonProtocol.JsonOptionalField;
 import org.jetbrains.jsonProtocol.JsonSubtypeCasting;
 
 import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.*;
 
@@ -63,24 +63,23 @@ final class FieldProcessor<T> {
 
   private MethodHandler processFieldGetterMethod(@NotNull Method method, @NotNull String fieldName) {
     Type genericReturnType = method.getGenericReturnType();
-    boolean nullable;
-    if (method.getAnnotation(JsonNullable.class) != null) {
-      nullable = true;
-    }
-    else if (genericReturnType == String.class || genericReturnType == Enum.class || (genericReturnType instanceof Class && !((Class)genericReturnType).isPrimitive())) {
-      JsonField jsonField = method.getAnnotation(JsonField.class);
-      if (jsonField != null) {
-        nullable = jsonField.optional() && !jsonField.allowAnyPrimitiveValue() && !jsonField.allowAnyPrimitiveValueAndMap();
-      }
-      else {
-        nullable = method.getAnnotation(JsonOptionalField.class) != null;
-      }
+    boolean addNotNullAnnotation;
+
+    boolean isPrimitive = genericReturnType instanceof Class ? ((Class)genericReturnType).isPrimitive() : !(genericReturnType instanceof ParameterizedType);
+    if (isPrimitive) {
+      addNotNullAnnotation = false;
     }
     else {
-      nullable = false;
+      JsonField jsonField = method.getAnnotation(JsonField.class);
+      if (jsonField != null) {
+        addNotNullAnnotation = !jsonField.optional() && !jsonField.allowAnyPrimitiveValue() && !jsonField.allowAnyPrimitiveValueAndMap();
+      }
+      else {
+        addNotNullAnnotation = method.getAnnotation(JsonOptionalField.class) == null;
+      }
     }
 
-    ValueReader fieldTypeParser = reader.getFieldTypeParser(genericReturnType, nullable, false, method);
+    ValueReader fieldTypeParser = reader.getFieldTypeParser(genericReturnType, false, method);
     if (fieldTypeParser != InterfaceReader.VOID_PARSER) {
       fieldLoaders.add(new FieldLoader(fieldName, fieldTypeParser));
     }
@@ -89,7 +88,7 @@ final class FieldProcessor<T> {
     return new MethodHandler() {
       @Override
       void writeMethodImplementationJava(@NotNull ClassScope scope, @NotNull Method method, @NotNull TextOutput out) {
-        if (!nullable) {
+        if (addNotNullAnnotation) {
           out.append("@NotNull").newLine();
         }
         writeMethodDeclarationJava(out, method);
@@ -103,7 +102,7 @@ final class FieldProcessor<T> {
   }
 
   private MethodHandler processManualSubtypeMethod(final Method m, JsonSubtypeCasting jsonSubtypeCaseAnn) {
-    ValueReader fieldTypeParser = reader.getFieldTypeParser(m.getGenericReturnType(), false, !jsonSubtypeCaseAnn.reinterpret(), null);
+    ValueReader fieldTypeParser = reader.getFieldTypeParser(m.getGenericReturnType(), !jsonSubtypeCaseAnn.reinterpret(), null);
     VolatileFieldBinding fieldInfo = allocateVolatileField(fieldTypeParser, true);
     LazyCachedMethodHandler handler = new LazyCachedMethodHandler(fieldTypeParser, fieldInfo);
     ObjectValueReader<?> parserAsObjectValueParser = fieldTypeParser.asJsonTypeParser();
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/InterfaceReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/InterfaceReader.java
index 2cb6b9a28d07..446a0a9150e1 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/InterfaceReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/InterfaceReader.java
@@ -18,19 +18,16 @@ class InterfaceReader {
   private static final PrimitiveValueReader LONG_PARSER = new PrimitiveValueReader("long", "-1");
 
   private static final PrimitiveValueReader INTEGER_PARSER = new PrimitiveValueReader("int", "-1");
-  private static final PrimitiveValueReader NULLABLE_INTEGER_PARSER = new PrimitiveValueReader("int", "-1", true, false);
 
   private static final PrimitiveValueReader BOOLEAN_PARSER = new PrimitiveValueReader("boolean");
   private static final PrimitiveValueReader FLOAT_PARSER = new PrimitiveValueReader("float");
 
   private static final PrimitiveValueReader NUMBER_PARSER = new PrimitiveValueReader("double");
-  private static final PrimitiveValueReader NULLABLE_NUMBER_PARSER = new PrimitiveValueReader("double", true);
 
   private static final PrimitiveValueReader STRING_PARSER = new PrimitiveValueReader("String");
-  private static final PrimitiveValueReader NULLABLE_STRING_PARSER = new PrimitiveValueReader("String", true);
 
-  private static final PrimitiveValueReader RAW_STRING_PARSER = new PrimitiveValueReader("String", null, false, true);
-  private static final PrimitiveValueReader RAW_STRING_OR_MAP_PARSER = new PrimitiveValueReader("Object", null, false, true) {
+  private static final PrimitiveValueReader RAW_STRING_PARSER = new PrimitiveValueReader("String", null, true);
+  private static final PrimitiveValueReader RAW_STRING_OR_MAP_PARSER = new PrimitiveValueReader("Object", null, true) {
     @Override
     void writeReadCode(ClassScope methodScope, boolean subtyping, String fieldName, TextOutput out) {
       out.append("readRawStringOrMap(");
@@ -40,14 +37,12 @@ class InterfaceReader {
   };
 
   private static final RawValueReader JSON_PARSER = new RawValueReader(false);
-  private static final RawValueReader NULLABLE_JSON_PARSER = new RawValueReader(true);
 
   private static final MapReader MAP_PARSER = new MapReader(false);
-  private static final MapReader NULLABLE_MAP_PARSER = new MapReader(true);
 
   private static final StringIntPairValueReader STRING_INT_PAIR_PARSER = new StringIntPairValueReader();
 
-  final static ValueReader VOID_PARSER = new ValueReader(true) {
+  final static ValueReader VOID_PARSER = new ValueReader() {
     @Override
     public void appendFinishedValueTypeName(TextOutput out) {
       out.append("void");
@@ -59,7 +54,7 @@ class InterfaceReader {
     }
 
     @Override
-    void writeArrayReadCode(ClassScope scope, boolean subtyping, boolean nullable, String fieldName, TextOutput out) {
+    void writeArrayReadCode(ClassScope scope, boolean subtyping, TextOutput out) {
       throw new UnsupportedOperationException();
     }
   };
@@ -175,68 +170,59 @@ class InterfaceReader {
                               fields.lazyRead);
   }
 
-  ValueReader getFieldTypeParser(Type type, boolean declaredNullable, boolean isSubtyping, @Nullable Method method) {
+  ValueReader getFieldTypeParser(Type type, boolean isSubtyping, @Nullable Method method) {
     if (type instanceof Class) {
       Class<?> typeClass = (Class<?>)type;
       if (type == Long.TYPE) {
-        nullableIsNotSupported(declaredNullable);
         return LONG_PARSER;
       }
       else if (type == Integer.TYPE) {
-        return declaredNullable ? NULLABLE_INTEGER_PARSER : INTEGER_PARSER;
+        return INTEGER_PARSER;
       }
       else if (type == Boolean.TYPE) {
-        nullableIsNotSupported(declaredNullable);
         return BOOLEAN_PARSER;
       }
       else if (type == Float.TYPE) {
-        nullableIsNotSupported(declaredNullable);
         return FLOAT_PARSER;
       }
       else if (type == Number.class || type == Double.TYPE) {
-        return declaredNullable ? NULLABLE_NUMBER_PARSER : NUMBER_PARSER;
+        return NUMBER_PARSER;
       }
       else if (type == Void.TYPE) {
-        nullableIsNotSupported(declaredNullable);
         return VOID_PARSER;
       }
       else if (type == String.class) {
-        if (declaredNullable) {
-          return NULLABLE_STRING_PARSER;
-        }
-        else {
-          if (method != null) {
-            JsonField jsonField = method.getAnnotation(JsonField.class);
-            if (jsonField != null && jsonField.allowAnyPrimitiveValue()) {
-              return RAW_STRING_PARSER;
-            }
+        if (method != null) {
+          JsonField jsonField = method.getAnnotation(JsonField.class);
+          if (jsonField != null && jsonField.allowAnyPrimitiveValue()) {
+            return RAW_STRING_PARSER;
           }
-          return STRING_PARSER;
         }
+        return STRING_PARSER;
       }
       else if (type == Object.class) {
         return RAW_STRING_OR_MAP_PARSER;
       }
       else if (type == JsonReaderEx.class) {
-        return declaredNullable ? NULLABLE_JSON_PARSER : JSON_PARSER;
+        return JSON_PARSER;
       }
       else if (type == Map.class) {
-        return declaredNullable ? NULLABLE_MAP_PARSER : MAP_PARSER;
+        return MAP_PARSER;
       }
       else if (type == StringIntPair.class) {
         return STRING_INT_PAIR_PARSER;
       }
       else if (typeClass.isArray()) {
-        return new ArrayReader(getFieldTypeParser(typeClass.getComponentType(), false, false, null), false,
-                               declaredNullable);
+        return new ArrayReader(getFieldTypeParser(typeClass.getComponentType(), false, null), false
+        );
       }
       else if (typeClass.isEnum()) {
         //noinspection unchecked
-        return EnumReader.create((Class<RetentionPolicy>)typeClass, declaredNullable);
+        return EnumReader.create((Class<RetentionPolicy>)typeClass);
       }
       TypeRef<?> ref = getTypeRef(typeClass);
       if (ref != null) {
-        return createJsonParser(ref, declaredNullable, isSubtyping);
+        return createJsonParser(ref, isSubtyping);
       }
       throw new JsonProtocolModelParseException("Method return type " + type + " (simple class) not supported");
     }
@@ -250,10 +236,10 @@ class InterfaceReader {
             argumentType = wildcard.getUpperBounds()[0];
           }
         }
-        return new ArrayReader(getFieldTypeParser(argumentType, false, false, method), true, declaredNullable);
+        return new ArrayReader(getFieldTypeParser(argumentType, false, method), true);
       }
       else if (parameterizedType.getRawType() == Map.class) {
-        return declaredNullable ? NULLABLE_MAP_PARSER : MAP_PARSER;
+        return MAP_PARSER;
       }
       else {
         throw new JsonProtocolModelParseException("Method return type " + type + " (generic) not supported");
@@ -264,14 +250,8 @@ class InterfaceReader {
     }
   }
 
-  private static void nullableIsNotSupported(boolean declaredNullable) {
-    if (declaredNullable) {
-      throw new JsonProtocolModelParseException("The type cannot be declared nullable");
-    }
-  }
-
-  private static <T> ObjectValueReader<T> createJsonParser(TypeRef<T> type, boolean isNullable, boolean isSubtyping) {
-    return new ObjectValueReader<>(type, isNullable, isSubtyping);
+  private static <T> ObjectValueReader<T> createJsonParser(TypeRef<T> type, boolean isSubtyping) {
+    return new ObjectValueReader<>(type, isSubtyping);
   }
 
   <T> TypeRef<T> getTypeRef(Class<T> typeClass) {
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/MapReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/MapReader.java
index a9376f27e22a..c7b9c6578a92 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/MapReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/MapReader.java
@@ -2,7 +2,7 @@ package org.jetbrains.protocolReader;
 
 public class MapReader extends ValueReader {
   MapReader(boolean nullable) {
-    super(nullable);
+    super();
   }
 
   @Override
@@ -12,15 +12,14 @@ public class MapReader extends ValueReader {
 
   @Override
   void writeReadCode(ClassScope scope, boolean subtyping, String fieldName, TextOutput out) {
-    beginReadCall("Map", subtyping, out, fieldName);
+    beginReadCall("Map", subtyping, out);
     out.append(')');
   }
 
   @Override
   void writeArrayReadCode(ClassScope scope,
                           boolean subtyping,
-                          boolean nullable,
-                          String fieldName, TextOutput out) {
+                          TextOutput out) {
     throw new UnsupportedOperationException();
   }
 }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ObjectValueReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ObjectValueReader.java
index 9f8e3c9b63c7..686fc5aa43db 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ObjectValueReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ObjectValueReader.java
@@ -1,15 +1,11 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
 package org.jetbrains.protocolReader;
 
 class ObjectValueReader<T> extends ValueReader {
   private final TypeRef<T> refToType;
   private final boolean isSubtyping;
 
-  ObjectValueReader(TypeRef<T> refToType, boolean nullable, boolean isSubtyping) {
-    super(nullable);
+  ObjectValueReader(TypeRef<T> refToType, boolean isSubtyping) {
+    super();
 
     this.refToType = refToType;
     this.isSubtyping = isSubtyping;
@@ -51,9 +47,9 @@ class ObjectValueReader<T> extends ValueReader {
   }
 
   @Override
-  public void writeArrayReadCode(ClassScope scope, boolean subtyping, boolean nullable, String fieldName, TextOutput out) {
-    beginReadCall("ObjectArray", subtyping, out, fieldName);
+  public void writeArrayReadCode(ClassScope scope, boolean subtyping, TextOutput out) {
+    beginReadCall("ObjectArray", subtyping, out);
     out.comma().append("new ").append(scope.requireFactoryGenerationAndGetName(refToType.get())).append(Util.TYPE_FACTORY_NAME_POSTFIX).append("()");
-    out.comma().append(nullable).append(')');
+    out.append(')');
   }
 }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/PrimitiveValueReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/PrimitiveValueReader.java
index 4f950fc4bb44..e5c3db3edeae 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/PrimitiveValueReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/PrimitiveValueReader.java
@@ -8,19 +8,15 @@ class PrimitiveValueReader extends ValueReader {
   private final boolean asRawString;
 
   PrimitiveValueReader(String name) {
-    this(name, false);
-  }
-
-  PrimitiveValueReader(String name, boolean nullable) {
-    this(name, null, nullable, false);
+    this(name, null, false);
   }
 
   PrimitiveValueReader(String name, String defaultValue) {
-    this(name, defaultValue, false, false);
+    this(name, defaultValue, false);
   }
 
-  public PrimitiveValueReader(String name, String defaultValue, boolean nullable, boolean asRawString) {
-    super(nullable);
+  public PrimitiveValueReader(String name, String defaultValue, boolean asRawString) {
+    super();
 
     this.defaultValue = defaultValue;
     this.asRawString = asRawString;
@@ -55,8 +51,7 @@ class PrimitiveValueReader extends ValueReader {
   @Override
   public void writeArrayReadCode(ClassScope scope,
                                  boolean subtyping,
-                                 boolean nullable,
-                                 String fieldName, TextOutput out) {
+                                 TextOutput out) {
     if (readPostfix.equals("String")) {
       out.append("nextList");
     }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/RawValueReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/RawValueReader.java
index 51eb0451d2c0..a8b46b87815a 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/RawValueReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/RawValueReader.java
@@ -4,7 +4,7 @@ import org.jetbrains.io.JsonReaderEx;
 
 class RawValueReader extends ValueReader {
   RawValueReader(boolean nullable) {
-    super(nullable);
+    super();
   }
 
   @Override
@@ -23,8 +23,7 @@ class RawValueReader extends ValueReader {
   @Override
   void writeArrayReadCode(ClassScope scope,
                           boolean subtyping,
-                          boolean nullable,
-                          String fieldName, TextOutput out) {
+                          TextOutput out) {
     throw new UnsupportedOperationException();
   }
 }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ReadDelegate.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ReadDelegate.java
index ca3253b1595b..102cb4944b2f 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ReadDelegate.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ReadDelegate.java
@@ -28,7 +28,7 @@ class ReadDelegate {
     out.openBlock();
     out.append("return ");
     if (isList) {
-      out.append("readObjectArray(").append(Util.READER_NAME).append(", null, new ").append(scope.requireFactoryGenerationAndGetName(typeHandler)).append(Util.TYPE_FACTORY_NAME_POSTFIX).append("()").append(", false)");
+      out.append("readObjectArray(").append(Util.READER_NAME).append(", new ").append(scope.requireFactoryGenerationAndGetName(typeHandler)).append(Util.TYPE_FACTORY_NAME_POSTFIX).append("()").append(")");
     }
     else {
       typeHandler.writeInstantiateCode(scope, out);
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/StringIntPairValueReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/StringIntPairValueReader.java
index f1019cbd146a..569f6cf0623a 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/StringIntPairValueReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/StringIntPairValueReader.java
@@ -2,7 +2,7 @@ package org.jetbrains.protocolReader;
 
 public class StringIntPairValueReader extends ValueReader {
   StringIntPairValueReader() {
-    super(false);
+    super();
   }
 
   @Override
@@ -17,8 +17,7 @@ public class StringIntPairValueReader extends ValueReader {
   @Override
   void writeArrayReadCode(ClassScope scope,
                           boolean subtyping,
-                          boolean nullable,
-                          String fieldName, TextOutput out) {
+                          TextOutput out) {
     out.append("read").append("IntStringPairs").append('(');
     addReaderParameter(subtyping, out);
     out.append(')');
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/TypeHandler.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/TypeHandler.java
index 983ce0c69d01..a5577ce563c8 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/TypeHandler.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/TypeHandler.java
@@ -152,8 +152,7 @@ class TypeHandler<T> {
     else {
       out.append("if (name == null)").openBlock();
       {
-        out.append("reader.beginObject()").semi();
-        out.newLine().append("if (reader.hasNext())").openBlock();
+        out.append("if (reader.beginObject().hasNext())").openBlock();
         {
           out.append("name = reader.nextName()").semi();
         }
diff --git a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ValueReader.java b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ValueReader.java
index 442167687b40..8b81b42470ed 100644
--- a/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ValueReader.java
+++ b/platform/script-debugger/protocol/protocol-reader/src/org/jetbrains/protocolReader/ValueReader.java
@@ -1,18 +1,10 @@
 package org.jetbrains.protocolReader;
 
-import org.jetbrains.annotations.Nullable;
-
 /**
  * A parser that accepts value of JSON field and outputs value in another form (e.g. string
  * is converted to enum constant) to serve field getters in JsonType interfaces.
  */
 abstract class ValueReader {
-  private final boolean nullable;
-
-  protected ValueReader(boolean nullable) {
-    this.nullable = nullable;
-  }
-
   public ObjectValueReader asJsonTypeParser() {
     return null;
   }
@@ -25,31 +17,12 @@ abstract class ValueReader {
 
   abstract void writeReadCode(ClassScope methodScope, boolean subtyping, String fieldName, TextOutput out);
 
-  public boolean isNullable() {
-    return nullable;
-  }
+  abstract void writeArrayReadCode(ClassScope scope, boolean subtyping, TextOutput out);
 
-  abstract void writeArrayReadCode(ClassScope scope, boolean subtyping, boolean nullable, String fieldName, TextOutput out);
-
-  protected void beginReadCall(String readPostfix, boolean subtyping, TextOutput out, @Nullable String fieldName) {
+  protected void beginReadCall(String readPostfix, boolean subtyping, TextOutput out) {
     out.append("read");
-    if (isNullable()) {
-      out.append("Nullable");
-    }
     out.append(readPostfix).append('(');
     addReaderParameter(subtyping, out);
-    if (!isNullable()) {
-      out.comma();
-      if (subtyping) {
-        out.append("null");
-      }
-      else if (fieldName == null) {
-        out.append("name");
-      }
-      else {
-        out.quote(fieldName);
-      }
-    }
   }
 
   protected static void addReaderParameter(boolean subtyping, TextOutput out) {