Validate getters marked as nullable on parse error only return null if there's a parse error.

idea/src/org/jetbrains/jet/JetNodeTypes.java

@@ -108,6 +108,7 @@ public interface JetNodeTypes {
     JetNodeType DOT_QIALIFIED_EXPRESSION  = new JetNodeType("DOT_QIALIFIED_EXPRESSION", JetDotQualifiedExpression.class);
     JetNodeType HASH_QIALIFIED_EXPRESSION = new JetNodeType("HASH_QIALIFIED_EXPRESSION", JetHashQualifiedExpression.class);
     JetNodeType SAFE_ACCESS_EXPRESSION    = new JetNodeType("SAFE_ACCESS_EXPRESSION", JetSafeQualifiedExpression.class);
+    JetNodeType EMPTY_EXPRESSION          = new JetNodeType("EMPTY_EXPRESSION", JetEmptyExpression.class);
     JetNodeType MATCH_BLOCK               = new JetNodeType("MATCH_BLOCK", JetMatchBlock.class);
     JetNodeType MATCH_ENTRY               = new JetNodeType("MATCH_ENTRY");
     JetNodeType PATTERN                   = new JetNodeType("PATTERN");

idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java

@@ -856,8 +856,14 @@ public class JetExpressionParsing extends AbstractJetParsing {
      */
     private void parseControlStructureBody() {
         PsiBuilder.Marker body = mark();
-        if (!at(SEMICOLON))
+        if (at(SEMICOLON)) {
+            PsiBuilder.Marker mark = mark();
+            advance();
+            mark.done(EMPTY_EXPRESSION);
+        }
+        else {
             parseExpression();
+        }
         body.done(BODY);
     }
 

idea/src/org/jetbrains/jet/lang/psi/JetArgument.java

@@ -17,7 +17,7 @@ public class JetArgument extends JetElement {
         visitor.visitArgument(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getArgumentExpression() {
         return findChildByClass(JetExpression.class);
     }

idea/src/org/jetbrains/jet/lang/psi/JetAttribute.java

@@ -21,9 +21,9 @@ public class JetAttribute extends JetElement {
         visitor.visitAttribute(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
-    public JetTypeReference getTypeReference() {
+    public JetUserType getTypeReference() {
-        return (JetTypeReference) findChildByType(JetNodeTypes.TYPE_REFERENCE);
+        return (JetUserType) findChildByType(JetNodeTypes.USER_TYPE);
     }
 
     @Nullable

idea/src/org/jetbrains/jet/lang/psi/JetBinaryExpression.java

@@ -27,7 +27,7 @@ public class JetBinaryExpression extends JetExpression {
         return left;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getRight() {
         ASTNode node = getOperationTokenNode();
         while (node != null) {

idea/src/org/jetbrains/jet/lang/psi/JetBinaryExpressionWithTypeRHS.java

@@ -27,7 +27,7 @@ public class JetBinaryExpressionWithTypeRHS extends JetExpression {
         return left;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getRight() {
         ASTNode node = getOperationTokenNode();
         while (node != null) {

idea/src/org/jetbrains/jet/lang/psi/JetCatchSection.java

@@ -20,12 +20,12 @@ public class JetCatchSection extends JetElement {
         visitor.visitCatchSection(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetParameterList getParameterList() {
         return (JetParameterList) findChildByType(JetNodeTypes.VALUE_PARAMETER_LIST);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetParameter getCatchParameter() {
         JetParameterList list = getParameterList();
         if (list == null) return null;
@@ -34,7 +34,7 @@ public class JetCatchSection extends JetElement {
     }
 
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getCatchBody() {
         return findChildByClass(JetExpression.class);
     }

idea/src/org/jetbrains/jet/lang/psi/JetConstructor.java

@@ -21,7 +21,7 @@ public class JetConstructor extends JetDeclaration {
         visitor.visitConstructor(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetParameterList getParameterList() {
         return (JetParameterList) findChildByType(JetNodeTypes.VALUE_PARAMETER_LIST);
     }

idea/src/org/jetbrains/jet/lang/psi/JetDecomposer.java

@@ -21,7 +21,7 @@ public class JetDecomposer extends JetNamedDeclaration {
         visitor.visitDecomposer(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetDecomposerPropertyList getPropertyList() {
         return (JetDecomposerPropertyList) findChildByType(JetNodeTypes.DECOMPOSER_PROPERTY_LIST);
     }

idea/src/org/jetbrains/jet/lang/psi/JetDoWhileExpression.java

@@ -18,12 +18,12 @@ public class JetDoWhileExpression extends JetExpression {
         visitor.visitDoWhileExpression(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getCondition() {
         return findExpressionUnder(JetNodeTypes.CONDITION);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable
     public JetExpression getBody() {
         return findExpressionUnder(JetNodeTypes.BODY);
     }

idea/src/org/jetbrains/jet/lang/psi/JetElement.java

@@ -7,6 +7,11 @@ import com.intellij.psi.PsiElementVisitor;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.JetLanguage;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
 /**
  * @author max
  */
@@ -15,7 +20,12 @@ public class JetElement extends ASTWrapperPsiElement {
         super(node);
     }
 
-    protected static final String IF_NOT_PARSED = "Returns null if has parsing error";
+    /**
+     * Comes along with @Nullable to indicate null is only possible if parsing error present
+     */
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.METHOD})
+    public static @interface IfNotParsed {}
 
     @NotNull
     @Override

idea/src/org/jetbrains/jet/lang/psi/JetEmptyExpression.java

@@ -0,0 +1,18 @@
+package org.jetbrains.jet.lang.psi;
+
+import com.intellij.lang.ASTNode;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author max
+ */
+public class JetEmptyExpression extends JetExpression {
+    public JetEmptyExpression(@NotNull ASTNode node) {
+        super(node);
+    }
+
+    @Override
+    public void accept(JetVisitor visitor) {
+        visitor.visitEmptyExpression(this);
+    }
+}

idea/src/org/jetbrains/jet/lang/psi/JetExtension.java

@@ -29,7 +29,7 @@ public class JetExtension extends JetTypeParameterListOwner {
         return body.getDeclarations();
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getTargetTypeRef() {
         return (JetTypeReference) findChildByType(JetNodeTypes.TYPE_REFERENCE);
     }

idea/src/org/jetbrains/jet/lang/psi/JetFunction.java

@@ -24,7 +24,7 @@ public class JetFunction extends JetTypeParameterListOwner {
         visitor.visitFunction(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetParameterList getParameterList() {
         return (JetParameterList) findChildByType(JetNodeTypes.VALUE_PARAMETER_LIST);
     }

idea/src/org/jetbrains/jet/lang/psi/JetIfExpression.java

@@ -18,12 +18,12 @@ public class JetIfExpression extends JetExpression {
         visitor.visitIfExpression(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getCondition() {
         return findExpressionUnder(JetNodeTypes.CONDITION);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable
     public JetExpression getThen() {
         return findExpressionUnder(JetNodeTypes.THEN);
     }

idea/src/org/jetbrains/jet/lang/psi/JetMatchExpression.java

@@ -25,7 +25,7 @@ public class JetMatchExpression extends JetExpression {
         return left;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetMatchBlock getMatchBlock() {
         return (JetMatchBlock) findChildByType(JetNodeTypes.MATCH_BLOCK);
     }

idea/src/org/jetbrains/jet/lang/psi/JetNewExpression.java

@@ -21,7 +21,7 @@ public class JetNewExpression extends JetExpression {
         visitor.visitNewExpression(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getTypeReference() {
         return (JetTypeReference) findChildByType(JetNodeTypes.TYPE_REFERENCE);
     }

idea/src/org/jetbrains/jet/lang/psi/JetQualifiedExpression.java

@@ -22,7 +22,7 @@ public abstract class JetQualifiedExpression extends JetExpression {
         return left;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getSelectorExpression() {
         ASTNode node = getOperationTokenNode();
         while (node != null) {

idea/src/org/jetbrains/jet/lang/psi/JetThrowExpression.java

@@ -17,7 +17,7 @@ public class JetThrowExpression extends JetExpression {
         visitor.visitThrowExpression(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getThrownExpression() {
         return findChildByClass(JetExpression.class);
     }

idea/src/org/jetbrains/jet/lang/psi/JetTypeConstraint.java

@@ -25,7 +25,7 @@ public class JetTypeConstraint extends JetElement {
                 findChildByType(JetTokens.OBJECT_KEYWORD) != null;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getSubjectTypeReference() {
         ASTNode node = getNode().getFirstChildNode();
         while (node != null) {
@@ -38,7 +38,7 @@ public class JetTypeConstraint extends JetElement {
         return null;
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getExtendsTypeReference() {
         boolean passedColon = false;
         ASTNode node = getNode().getFirstChildNode();

idea/src/org/jetbrains/jet/lang/psi/JetTypedef.java

@@ -18,7 +18,7 @@ public class JetTypedef extends JetTypeParameterListOwner {
         visitor.visitTypedef(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetTypeReference getTypeReference() {
         return (JetTypeReference) findChildByType(JetNodeTypes.TYPE_REFERENCE);
     }

idea/src/org/jetbrains/jet/lang/psi/JetVisitor.java

@@ -325,4 +325,8 @@ public class JetVisitor extends PsiElementVisitor {
     public void visitMatchBlock(JetMatchBlock block) {
         visitJetElement(block);
     }
+
+    public void visitEmptyExpression(JetEmptyExpression expression) {
+        visitExpression(expression);
+    }
 }

idea/src/org/jetbrains/jet/lang/psi/JetWhileExpression.java

@@ -18,12 +18,12 @@ public class JetWhileExpression extends JetExpression {
         visitor.visitWhileExpression(this);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getCondition() {
         return findExpressionUnder(JetNodeTypes.CONDITION);
     }
 
-    @Nullable(IF_NOT_PARSED)
+    @Nullable @IfNotParsed
     public JetExpression getBody() {
         return findExpressionUnder(JetNodeTypes.BODY);
     }

idea/testData/psi/ControlStructures.txt

@@ -642,7 +642,7 @@ JetFile: ControlStructures.jet
                   PsiElement(IDENTIFIER)('b')
               PsiElement(RPAR)(')')
               BODY
-                <empty list>
+                EMPTY_EXPRESSION
                   PsiElement(SEMICOLON)(';')
             PsiWhiteSpace('\n      ')
             REFERENCE_EXPRESSION
@@ -707,7 +707,7 @@ JetFile: ControlStructures.jet
                     PsiElement(IDENTIFIER)('b')
               PsiElement(RPAR)(')')
               BODY
-                <empty list>
+                EMPTY_EXPRESSION
                   PsiElement(SEMICOLON)(';')
             PsiWhiteSpace('\n      ')
             REFERENCE_EXPRESSION

idea/tests/org/jetbrains/jet/parsing/JetParsingTest.java

@@ -10,15 +10,14 @@ import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.testFramework.ParsingTestCase;
 import junit.framework.TestSuite;
 import org.jetbrains.annotations.NonNls;
-import org.jetbrains.jet.lang.psi.JetBinaryExpression;
 import org.jetbrains.jet.lang.psi.JetElement;
-import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetVisitor;
 
 import java.io.File;
 import java.io.FileFilter;
 import java.io.FilenameFilter;
 import java.io.IOException;
+import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collections;
@@ -61,17 +60,6 @@ public class JetParsingTest extends ParsingTestCase {
                     throw new RuntimeException(throwable);
                 }
             }
-
-            @Override
-            public void visitBinaryExpression(JetBinaryExpression expression) {
-                super.visitBinaryExpression(expression);
-                JetExpression right = expression.getRight();
-                JetExpression left = expression.getLeft();
-                assertNotSame(left, right);
-                if (right == null) {
-                    assertNotNull("Imcomplete binary operation in parsed OK test", PsiTreeUtil.findChildOfType(expression, PsiErrorElement.class) != null);
-                }
-            }
         });
 
         super.checkResult(targetDataName, file);
@@ -85,7 +73,17 @@ public class JetParsingTest extends ParsingTestCase {
             Class<?> declaringClass = method.getDeclaringClass();
             if (!declaringClass.getName().startsWith("org.jetbrains.jet")) continue;
 
-            method.invoke(elem);
+            Object result = method.invoke(elem);
+            if (result == null) {
+                for (Annotation annotation : method.getDeclaredAnnotations()) {
+                    if (annotation instanceof JetElement.IfNotParsed) {
+                        assertNotNull(
+                                "Imcomplete operation in parsed OK test, method " + method.getName() +
+                                " in " + declaringClass.getSimpleName() + " returns null. Element text: \n" + elem.getText(),
+                                PsiTreeUtil.findChildOfType(elem, PsiErrorElement.class));
+                    }
+                }
+            }
         }
     }