disable for->foreach inspection if iterator is used in method reference qualifier (IDEA-136642)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/migration/ForCanBeForeachInspectionBase.java

@@ -178,14 +178,12 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     return visitor.isIndexVariableUsedOnlyAsIndex();
   }
 
-  static boolean isCollectionLoopStatement(
-    PsiForStatement forStatement, boolean ignoreUntypedCollections) {
+  static boolean isCollectionLoopStatement(PsiForStatement forStatement, boolean ignoreUntypedCollections) {
     final PsiStatement initialization = forStatement.getInitialization();
     if (!(initialization instanceof PsiDeclarationStatement)) {
       return false;
     }
-    final PsiDeclarationStatement declaration =
-      (PsiDeclarationStatement)initialization;
+    final PsiDeclarationStatement declaration = (PsiDeclarationStatement)initialization;
     final PsiElement[] declaredElements = declaration.getDeclaredElements();
     if (declaredElements.length != 1) {
       return false;
@@ -195,9 +193,7 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
       return false;
     }
     final PsiVariable variable = (PsiVariable)declaredElement;
-    if (!TypeUtils.variableHasTypeOrSubtype(variable,
-                                            CommonClassNames.JAVA_UTIL_ITERATOR,
-                                            "java.util.ListIterator")) {
+    if (!TypeUtils.variableHasTypeOrSubtype(variable, CommonClassNames.JAVA_UTIL_ITERATOR, "java.util.ListIterator")) {
       return false;
     }
     final PsiExpression initialValue = variable.getInitializer();
@@ -207,14 +203,10 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     if (!(initialValue instanceof PsiMethodCallExpression)) {
       return false;
     }
-    final PsiMethodCallExpression initialCall =
-      (PsiMethodCallExpression)initialValue;
-    final PsiReferenceExpression initialMethodExpression =
-      initialCall.getMethodExpression();
-    @NonNls final String initialCallName =
-      initialMethodExpression.getReferenceName();
-    if (!HardcodedMethodConstants.ITERATOR.equals(initialCallName) &&
-        !"listIterator".equals(initialCallName)) {
+    final PsiMethodCallExpression initialCall = (PsiMethodCallExpression)initialValue;
+    final PsiReferenceExpression initialMethodExpression = initialCall.getMethodExpression();
+    @NonNls final String initialCallName = initialMethodExpression.getReferenceName();
+    if (!HardcodedMethodConstants.ITERATOR.equals(initialCallName) && !"listIterator".equals(initialCallName)) {
       return false;
     }
     final PsiExpressionList argumentList = initialCall.getArgumentList();
@@ -222,12 +214,10 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     if (arguments.length != 0) {
       return false;
     }
-    final PsiExpression qualifier =
-      initialMethodExpression.getQualifierExpression();
+    final PsiExpression qualifier = initialMethodExpression.getQualifierExpression();
     final PsiClass qualifierClass;
     if (qualifier == null) {
-      qualifierClass =
-        ClassUtils.getContainingClass(initialMethodExpression);
+      qualifierClass = ClassUtils.getContainingClass(initialMethodExpression);
       if (ignoreUntypedCollections) {
         final PsiClassType type = (PsiClassType)variable.getType();
         final PsiType[] parameters = type.getParameters();
@@ -255,10 +245,8 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     if (qualifierClass == null) {
       return false;
     }
-    if (!InheritanceUtil.isInheritor(qualifierClass,
-                                     CommonClassNames.JAVA_LANG_ITERABLE) &&
-        !InheritanceUtil.isInheritor(qualifierClass,
-                                     CommonClassNames.JAVA_UTIL_COLLECTION)) {
+    if (!InheritanceUtil.isInheritor(qualifierClass, CommonClassNames.JAVA_LANG_ITERABLE) &&
+        !InheritanceUtil.isInheritor(qualifierClass, CommonClassNames.JAVA_UTIL_COLLECTION)) {
       return false;
     }
     final PsiExpression condition = forStatement.getCondition();
@@ -289,16 +277,13 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     if (body == null) {
       return 0;
     }
-    final NumCallsToIteratorNextVisitor visitor =
-      new NumCallsToIteratorNextVisitor(iterator);
+    final NumCallsToIteratorNextVisitor visitor = new NumCallsToIteratorNextVisitor(iterator);
     body.accept(visitor);
     return visitor.getNumCallsToIteratorNext();
   }
 
-  private static boolean isIteratorMethodCalled(PsiVariable iterator,
-                                                PsiStatement body) {
-    final IteratorMethodCallVisitor visitor =
-      new IteratorMethodCallVisitor(iterator);
+  private static boolean isIteratorMethodCalled(PsiVariable iterator, PsiStatement body) {
+    final IteratorMethodCallVisitor visitor = new IteratorMethodCallVisitor(iterator);
     body.accept(visitor);
     return visitor.isMethodCalled();
   }
@@ -308,29 +293,25 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     if (!(condition instanceof PsiMethodCallExpression)) {
       return false;
     }
-    final PsiMethodCallExpression call =
-      (PsiMethodCallExpression)condition;
+    final PsiMethodCallExpression call = (PsiMethodCallExpression)condition;
     final PsiExpressionList argumentList = call.getArgumentList();
     final PsiExpression[] arguments = argumentList.getExpressions();
     if (arguments.length != 0) {
       return false;
     }
-    final PsiReferenceExpression methodExpression =
-      call.getMethodExpression();
+    final PsiReferenceExpression methodExpression = call.getMethodExpression();
     final String methodName = methodExpression.getReferenceName();
     if (!HardcodedMethodConstants.HAS_NEXT.equals(methodName)) {
       return false;
     }
-    final PsiExpression qualifier =
-      methodExpression.getQualifierExpression();
+    final PsiExpression qualifier = methodExpression.getQualifierExpression();
     if (qualifier == null) {
       return true;
     }
     if (!(qualifier instanceof PsiReferenceExpression)) {
       return false;
     }
-    final PsiReferenceExpression referenceExpression =
-      (PsiReferenceExpression)qualifier;
+    final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier;
     final PsiElement target = referenceExpression.resolve();
     return iterator.equals(target);
   }
@@ -636,31 +617,39 @@ public class ForCanBeForeachInspectionBase extends BaseInspection {
     }
 
     @Override
-    public void visitMethodCallExpression(
-      @NotNull PsiMethodCallExpression expression) {
+    public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression) {
       if (methodCalled) {
         return;
       }
       super.visitMethodCallExpression(expression);
-      final PsiReferenceExpression methodExpression =
-        expression.getMethodExpression();
+      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
       final String name = methodExpression.getReferenceName();
       if (HardcodedMethodConstants.NEXT.equals(name)) {
         return;
       }
-      final PsiExpression qualifier =
-        methodExpression.getQualifierExpression();
+      final PsiExpression qualifier = methodExpression.getQualifierExpression();
       if (!(qualifier instanceof PsiReferenceExpression)) {
         return;
       }
-      final PsiReferenceExpression referenceExpression =
-        (PsiReferenceExpression)qualifier;
+      final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier;
       final PsiElement target = referenceExpression.resolve();
       if (iterator.equals(target)) {
         methodCalled = true;
       }
     }
 
+    @Override
+    public void visitMethodReferenceExpression(PsiMethodReferenceExpression expression) {
+      if (methodCalled) {
+        return;
+      }
+      super.visitMethodReferenceExpression(expression);
+      final PsiExpression qualifierExpression = expression.getQualifierExpression();
+      if (qualifierExpression instanceof PsiReferenceExpression && iterator.equals(((PsiReferenceExpression)qualifierExpression).resolve())) {
+        methodCalled = true;
+      }
+    }
+
     public boolean isMethodCalled() {
       return methodCalled;
     }

plugins/InspectionGadgets/test/com/siyeh/igtest/migration/foreach/ForCanBeForEach.java

@@ -273,6 +273,20 @@ public class ForCanBeForEach {
       }
     }
   }
+
+  static class WithMethodRefs {
+      private static final List<String> STRINGS = new ArrayList<>(Arrays.asList("Hello", "World"));
+
+      public void test3() {
+          for (ListIterator<String> stringListIterator = STRINGS.listIterator(); stringListIterator.hasNext(); ) {
+              System.out.println(stringListIterator.next());
+
+              List<String> strings2 = new ArrayList<>(Collections.singletonList("!"));
+
+              strings2.forEach(stringListIterator::add);
+          }
+      }
+  }
 }
 class OuterClass
 {

plugins/InspectionGadgets/testsrc/com/siyeh/ig/migration/ForCanBeForeachInspectionTest.java

@@ -1,7 +1,9 @@
 package com.siyeh.ig.migration;
 
 import com.intellij.codeInspection.InspectionProfileEntry;
+import com.intellij.testFramework.LightProjectDescriptor;
 import com.siyeh.ig.LightInspectionTestCase;
+import org.jetbrains.annotations.NotNull;
 
 public class ForCanBeForeachInspectionTest extends LightInspectionTestCase {
 
@@ -18,4 +20,10 @@ public class ForCanBeForeachInspectionTest extends LightInspectionTestCase {
   protected String getBasePath() {
     return "/plugins/InspectionGadgets/test/com/siyeh/igtest/migration/foreach";
   }
+
+  @NotNull
+  @Override
+  protected LightProjectDescriptor getProjectDescriptor() {
+    return JAVA_8;
+  }
 }