IDEA-136413 ("Overly strong type cast" warning should take into account checked exceptions)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ExpectedTypeUtils.java

@@ -15,6 +15,7 @@
  */
 package com.siyeh.ig.psiutils;
 
+import com.intellij.codeInsight.ExceptionUtil;
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.*;
 import com.intellij.psi.tree.IElementType;
@@ -22,10 +23,12 @@ import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.TypeConversionUtil;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.IncorrectOperationException;
+import com.intellij.util.containers.ContainerUtil;
 import gnu.trove.THashSet;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.HashSet;
 import java.util.Set;
 
 public class ExpectedTypeUtils {
@@ -526,9 +529,12 @@ public class ExpectedTypeUtils {
       if (aClass == null) {
         return null;
       }
+      final PsiReferenceList throwsList = method.getThrowsList();
+      final HashSet<PsiClassType> thrownTypes = ContainerUtil.newHashSet(throwsList.getReferencedTypes());
       final PsiMethod[] superMethods = aClass.findMethodsBySignature(method, true);
       PsiMethod topSuper = null;
       PsiClass topSuperContainingClass = null;
+      methodLoop:
       for (PsiMethod superMethod : superMethods) {
         final PsiClass superClass = superMethod.getContainingClass();
         if (superClass == null) {
@@ -552,6 +558,13 @@ public class ExpectedTypeUtils {
         if (topSuper != null && superClass.isInheritor(topSuperContainingClass, true)) {
           continue;
         }
+        final PsiReferenceList superThrowsList = superMethod.getThrowsList();
+        final PsiClassType[] superThrownTypes = superThrowsList.getReferencedTypes();
+        for (PsiClassType superThrownType : superThrownTypes) {
+          if (!ExceptionUtil.isUncheckedException(superThrownType) && !thrownTypes.contains(superThrownType)) {
+            continue methodLoop;
+          }
+        }
         topSuper = superMethod;
         topSuperContainingClass = superClass;
       }

plugins/InspectionGadgets/test/com/siyeh/igtest/abstraction/overly_strong_type_cast/OverlyStrongTypeCast.java

@@ -70,4 +70,22 @@ class SAM {
   {
     Object runnable = (Runnable) () -> {};
   }
+}
+class CloseableWarningTest {
+  private Object x = new Object();
+
+  public void example() {
+    //if (x instanceof SafeCloseable) {
+      ((SafeCloseable) x).close();
+    //}
+  }
+}
+
+interface SafeCloseable extends Closeable {
+  @Override
+  void close();
+}
+interface Closeable extends AutoCloseable {
+
+  public void close() throws java.io.IOException;
 }