From fa69bd0ec116704e38b8ea7c85bb552d78cdc1fc Mon Sep 17 00:00:00 2001
From: Andreas Dangel <andreas.dangel@pmd-code.org>
Date: Fri, 26 Nov 2021 09:12:14 +0100
Subject: [PATCH] [java] CloseResource - fix class cast exception with pattern
 matching

---
 .../lang/java/rule/errorprone/CloseResourceRule.java | 12 ++++++++++--
 .../lang/java/rule/errorprone/xml/CloseResource.xml  | 12 ++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/CloseResourceRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/CloseResourceRule.java
index 4d0ed46550..07fe312828 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/CloseResourceRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/CloseResourceRule.java
@@ -35,6 +35,7 @@ import net.sourceforge.pmd.lang.java.ast.ASTMethodCall;
 import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTMethodOrConstructorDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTNullLiteral;
+import net.sourceforge.pmd.lang.java.ast.ASTPatternExpression;
 import net.sourceforge.pmd.lang.java.ast.ASTReturnStatement;
 import net.sourceforge.pmd.lang.java.ast.ASTStatement;
 import net.sourceforge.pmd.lang.java.ast.ASTTryStatement;
@@ -214,8 +215,15 @@ public class CloseResourceRule extends AbstractJavaRule {
     }
 
     private TypeNode getDeclaredTypeOfVariable(ASTVariableDeclaratorId var) {
-        ASTLocalVariableDeclaration localVar = (ASTLocalVariableDeclaration) var.getParent().getParent();
-        return localVar.getTypeNode(); // note: can be null, if type is inferred (var)
+        JavaNode exprOrDecl = var.getParent().getParent();
+        if (exprOrDecl instanceof ASTLocalVariableDeclaration) {
+            ASTLocalVariableDeclaration localVar = (ASTLocalVariableDeclaration) exprOrDecl;
+            return localVar.getTypeNode(); // note: can be null, if type is inferred (var)
+        } else if (exprOrDecl instanceof ASTPatternExpression) {
+            ASTPatternExpression pattern = (ASTPatternExpression) exprOrDecl;
+            return pattern.descendants(TypeNode.class).first();
+        }
+        return null;
     }
 
     private TypeNode getRuntimeTypeOfVariable(ASTVariableDeclaratorId var) {
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/CloseResource.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/CloseResource.xml
index 1834d61109..c53e9b02b9 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/CloseResource.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/CloseResource.xml
@@ -1984,6 +1984,18 @@ public class CloseResourceForEachLoop {
     }
 
     private InputStream[] getStreams() { return null; }
+}
+        ]]></code>
+    </test-code>
+
+    <test-code>
+        <description>ClassCastException with pattern matching</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class TypePattern {
+    static boolean doStuff(Object obj) {
+        return obj instanceof Integer myIntVar && myIntVar > 0;
+    }
 }
         ]]></code>
     </test-code>