Java: don't report non-private field as assigned not accessed when it is implicitly read and written (IDEA-357404)

GitOrigin-RevId: 943ef6961c19510e5d4291367293424a87499487

java/java-analysis-impl/src/com/intellij/codeInspection/unusedSymbol/UnusedSymbolLocalInspection.java

@@ -196,7 +196,7 @@ public final class UnusedSymbolLocalInspection extends AbstractBaseJavaLocalInsp
           }
         }
         else if (!UnusedSymbolUtil.isFieldUsed(project, file, field, helper)) {
-          if (UnusedSymbolUtil.isImplicitWrite(project, field)) {
+          if (UnusedSymbolUtil.isImplicitWrite(project, field) && !UnusedSymbolUtil.isImplicitRead(project, field)) {
             registerProblem(field, getNotUsedForReadingMessage(field), List.of(fixFactory.createSafeDeleteFix(field)));
           }
           else if (!UnusedSymbolUtil.isImplicitUsage(project, field)) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/unusedDecls/ImplicitReadsWrites.java

@@ -0,0 +1,15 @@
+class <warning descr="Class 'Test' is never used">Test</warning>{
+  
+  private int <warning descr="Private field 'fieldWritten' is assigned but never accessed">fieldWritten</warning>;
+
+  private int fieldWritten2;
+  
+  int fieldReadWritten;
+  
+  int <warning descr="Package-private field 'fieldWritten3' is assigned but never accessed">fieldWritten3</warning><EOLError descr="';' expected"></EOLError>
+
+  @Override
+  public int hashCode() {
+    return fieldWritten2;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/unusedDecls/InjectedAnno.java

@@ -1,29 +0,0 @@
-package javax.annotation;
-
-/*
-* Copyright 2000-2011 JetBrains s.r.o.
-*
-* Licensed under the Apache License, Version 2.0 (the "License");
-* you may not use this file except in compliance with the License.
-* You may obtain a copy of the License at
-*
-* http://www.apache.org/licenses/LICENSE-2.0
-*
-* Unless required by applicable law or agreed to in writing, software
-* distributed under the License is distributed on an "AS IS" BASIS,
-* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-* See the License for the specific language governing permissions and
-* limitations under the License.
-*/
-@interface Resource {}
-class Test{
-  @Resource
-  private int <warning descr="Private field 'field' is assigned but never accessed">field</warning>;
-
-  @Resource
-  private int field2;
-
-  int f() {
-    return field2;
-  }
-}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/UnusedSymbolLocalTest.java

@@ -2,6 +2,7 @@
 package com.intellij.java.codeInsight.daemon;
 
 import com.intellij.codeInsight.daemon.DaemonAnalyzerTestCase;
+import com.intellij.codeInsight.daemon.ImplicitUsageProvider;
 import com.intellij.codeInsight.daemon.impl.HighlightInfo;
 import com.intellij.codeInspection.deadCode.UnusedDeclarationInspection;
 import com.intellij.lang.annotation.HighlightSeverity;
@@ -10,7 +11,10 @@ import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.PsiDocumentManager;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiField;
 import com.intellij.testFramework.IdeaTestUtil;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
 
@@ -41,7 +45,26 @@ public class UnusedSymbolLocalTest extends DaemonAnalyzerTestCase {
     });
   }
 
-  //public void testInjectedAnno() throws Exception { doTest(); }
+  public void testImplicitReadsWrites() throws Exception {
+    ImplicitUsageProvider.EP_NAME.getPoint().registerExtension(new ImplicitUsageProvider() {
+      @Override
+      public boolean isImplicitUsage(@NotNull PsiElement element) {
+        return isImplicitWrite(element) || isImplicitRead(element);
+      }
+
+      @Override
+      public boolean isImplicitRead(@NotNull PsiElement element) {
+        return element instanceof PsiField field && field.getName().contains("Read");
+      }
+
+      @Override
+      public boolean isImplicitWrite(@NotNull PsiElement element) {
+        return element instanceof PsiField field && field.getName().contains("Written");
+      }
+    }, getTestRootDisposable());
+
+    doTest(); 
+  }
 
   public void testChangeInsideCodeBlock() throws Exception {
     doTest();

plugins/lombok/testData/highlighting/LombokBasics.java

@@ -55,7 +55,7 @@ class <warning descr="Class 'IntellijInspectionNPEDemo' is never used">IntellijI
       }
     }
 
-    public final String <warning descr="Public field 'jsonObject' is assigned but never accessed">jsonObject</warning>;
+    public final String jsonObject;
   }
 
 }