[java] IDEA-216276 Provide fix for "method is already defined in"

For each "method is already defined in" error, a quick fix is added with "Navigate to duplicate method" text. In case of many duplicates, quick fix navigates to the topmost one.

Merge-request: IJ-MR-170181
Merged-by: Marcin Mikosik <marcin.mikosik@jetbrains.com>

GitOrigin-RevId: d609be3a3e4526bed37471f814d2e675cbd0d2a6

java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/MethodChecker.java

@@ -527,7 +527,7 @@ final class MethodChecker {
     MethodSignature methodSignature = method.getSignature(PsiSubstitutor.EMPTY);
     List<PsiMethod> methods = (List<PsiMethod>)duplicateMethods.get(methodSignature);
     if (methods.size() > 1) {
-      myVisitor.report(JavaErrorKinds.METHOD_DUPLICATE.create(method));
+      myVisitor.report(JavaErrorKinds.METHOD_DUPLICATE.create(method, new JavaErrorKinds.DuplicateMethodsContext(methods)));
     }
   }
 

java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/errors/JavaErrorKinds.java

@@ -640,11 +640,11 @@ public final class JavaErrorKinds {
                                                 owner.getTypeParameters().length));
   public static final Simple<PsiTypeElement> TYPE_PARAMETER_ACTUAL_INFERRED_MISMATCH = error("type.parameter.actual.inferred.mismatch");
 
-  public static final Simple<PsiMethod> METHOD_DUPLICATE =
-    error(PsiMethod.class, "method.duplicate")
-      .withRange(JavaErrorFormatUtil::getMethodDeclarationTextRange)
+  public static final Parameterized<PsiMethod, DuplicateMethodsContext> METHOD_DUPLICATE =
+    parameterized(PsiMethod.class, DuplicateMethodsContext.class, "method.duplicate")
+      .withRange((method, duplicates) -> getMethodDeclarationTextRange(method))
       .withDescription(
-        method -> message("method.duplicate", formatMethod(method), formatClass(requireNonNull(method.getContainingClass()))));
+        (method, duplicates) -> message("method.duplicate", formatMethod(method), formatClass(requireNonNull(method.getContainingClass()))));
   public static final Simple<PsiMethod> METHOD_NO_PARAMETER_LIST =
     error(PsiMethod.class, "method.no.parameter.list").withAnchor(PsiMethod::getNameIdentifier);
   public static final Simple<PsiJavaCodeReferenceElement> METHOD_THROWS_CLASS_NAME_EXPECTED =
@@ -1775,4 +1775,6 @@ public final class JavaErrorKinds {
   public record DeconstructionCountMismatchContext(@NotNull PsiPattern @NotNull [] patternComponents,
                                                    @NotNull PsiRecordComponent @NotNull [] recordComponents,
                                                    boolean hasMismatch) {}
+
+  public record DuplicateMethodsContext(@NotNull List<@NotNull PsiMethod> methods) {}
 }

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/DefaultJavaErrorFixProvider.java

@@ -14,6 +14,7 @@ import com.intellij.codeInspection.dataFlow.fix.RedundantInstanceofFix;
 import com.intellij.core.JavaPsiBundle;
 import com.intellij.ide.highlighter.JavaFileType;
 import com.intellij.java.analysis.JavaAnalysisBundle;
+import com.intellij.java.codeserver.core.JavaPsiMethodUtil;
 import com.intellij.java.codeserver.core.JavaPsiModifierUtil;
 import com.intellij.java.codeserver.core.JavaPsiSwitchUtil;
 import com.intellij.java.codeserver.core.JpmsModuleAccessInfo;
@@ -334,6 +335,13 @@ public final class DefaultJavaErrorFixProvider extends AbstractJavaErrorFixProvi
     fix(METHOD_GENERIC_CLASH, error ->
       error.context().method() instanceof SyntheticElement ?
       null : myFactory.createSameErasureButDifferentMethodsFix(error.context().method(), error.context().superMethod()));
+    fixes(METHOD_DUPLICATE, (error, sink) -> {
+      error.context().methods().stream()
+        .filter(m -> !m.equals(error.psi()))
+        .filter(m -> !(m instanceof SyntheticElement)) // filters out synthetic methods, such as Enum#values()
+        .findFirst()
+        .ifPresent(m -> sink.accept(myFactory.createNavigateToDuplicateElementFix(m)));
+    });
   }
 
   private void createExceptionFixes() {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/afterNavigatesFromFirstToSecond.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public void foo() {}
+  public void <selection><caret>foo</selection>() {}
+  public void foo() {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/afterNavigatesFromFirstToSecondGenericMethod.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public <T> void foo(T bar) {}
+  public <T> void <selection><caret>foo</selection>(T bar) {}
+  public <T> void foo(T bar) {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/afterNavigatesFromThirdToFirst.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public void <selection><caret>foo</selection>() {}
+  public void foo() {}
+  public void foo() {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/afterNavigatesToEnumValueOfWhenDeclaredTwice.java

@@ -0,0 +1,11 @@
+// "Navigate to duplicate method" "true"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum valueOf(String s) {
+    return null;
+  }
+  public MyEnum <selection><caret>valueOf</selection>(String s) {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/afterNavigatesToEnumValuesWhenDeclaredTwice.java

@@ -0,0 +1,11 @@
+// "Navigate to duplicate method" "true"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum[] values() {
+    return null;
+  }
+  public MyEnum[] <selection><caret>values</selection>() {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeDoesntNavigateToEnumValueOf.java

@@ -0,0 +1,8 @@
+// "Navigate to duplicate method" "false"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum valueOf<caret>(String s) {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeDoesntNavigateToEnumValues.java

@@ -0,0 +1,8 @@
+// "Navigate to duplicate method" "false"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum[] values<caret>() {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeNavigatesFromFirstToSecond.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public void foo<caret>() {}
+  public void foo() {}
+  public void foo() {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeNavigatesFromFirstToSecondGenericMethod.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public <T> void foo<caret>(T bar) {}
+  public <T> void foo(T bar) {}
+  public <T> void foo(T bar) {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeNavigatesFromThirdToFirst.java

@@ -0,0 +1,7 @@
+// "Navigate to duplicate method" "true"
+
+public class MyClass {
+  public void foo() {}
+  public void foo() {}
+  public void foo<caret>() {}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeNavigatesToEnumValueOfWhenDeclaredTwice.java

@@ -0,0 +1,11 @@
+// "Navigate to duplicate method" "true"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum valueOf<caret>(String s) {
+    return null;
+  }
+  public MyEnum valueOf(String s) {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix/beforeNavigatesToEnumValuesWhenDeclaredTwice.java

@@ -0,0 +1,11 @@
+// "Navigate to duplicate method" "true"
+
+enum MyEnum {
+  FIRST;
+  public MyEnum[] values<caret>() {
+    return null;
+  }
+  public MyEnum[] values() {
+    return null;
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/impl/quickfix/NavigateToDuplicateMethodFixTest.java

@@ -0,0 +1,11 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.codeInsight.daemon.impl.quickfix;
+
+import com.intellij.codeInsight.daemon.quickFix.LightQuickFixParameterizedTestCase;
+
+public class NavigateToDuplicateMethodFixTest extends LightQuickFixParameterizedTestCase {
+  @Override
+  protected String getBasePath() {
+    return "/codeInsight/daemonCodeAnalyzer/quickFix/navigateToDuplicateMethodFix";
+  }
+}