[java-highlighting] Provide quick-fix to replace 'var' with explicit type in language level smaller than Java 11

IDEA-256074 GitOrigin-RevId: 478ca1de890ec7c4346e4b2436c2b500c1489602
2026-09-27 10:03:11 +07:00 · 2022-02-16 06:11:34 +00:00
parent 5053b65a3f
commit 22e275ba54
13 changed files with 159 additions and 1 deletions
@@ -1,11 +1,17 @@
-// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2022 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.analysis;

 import com.intellij.codeInsight.daemon.QuickFixActionRegistrar;
+import com.intellij.codeInsight.intention.QuickFixFactory;
+import com.intellij.codeInsight.intention.impl.PriorityIntentionActionWrapper;
 import com.intellij.codeInsight.quickfix.UnresolvedReferenceQuickFixProvider;
 import com.intellij.psi.*;
+import com.intellij.psi.PsiClassType.ClassResolveResult;
+import com.intellij.psi.util.PsiTypesUtil;
+import com.intellij.psi.util.PsiUtil;
 import com.intellij.util.ObjectUtils;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;

 public class JavaFutureKeywordUseFixProvider extends UnresolvedReferenceQuickFixProvider<PsiJavaCodeReferenceElement> {
  @Override
@@ -14,6 +20,7 @@ public class JavaFutureKeywordUseFixProvider extends UnresolvedReferenceQuickFix
    if (typeElement == null || typeElement.getFirstChild() != typeElement.getLastChild()) return;
    PsiElement parent = typeElement.getParent();
    if (PsiKeyword.VAR.equals(ref.getReferenceName())) {
+      registerSetVariableTypeFix(parent, registrar);
      registerVarLanguageLevelFix(ref, parent, registrar);
    }
    if (PsiKeyword.RECORD.equals(ref.getReferenceName())) {
@@ -54,4 +61,42 @@ public class JavaFutureKeywordUseFixProvider extends UnresolvedReferenceQuickFix
  public Class<PsiJavaCodeReferenceElement> getReferenceClass() {
    return PsiJavaCodeReferenceElement.class;
  }
+
+  private static void registerSetVariableTypeFix(PsiElement parent, @NotNull QuickFixActionRegistrar registrar) {
+    PsiVariable variable = ObjectUtils.tryCast(parent, PsiVariable.class);
+    if (variable == null) return;
+    PsiType type = inferType(variable);
+    if (type == null) return;
+    registrar.register(PriorityIntentionActionWrapper.highPriority(QuickFixFactory.getInstance().createSetVariableTypeFix(variable, type)));
+  }
+
+  private static @Nullable PsiType inferType(@NotNull PsiVariable variable) {
+    if (variable instanceof PsiParameter && variable.getParent() instanceof PsiForeachStatement) {
+      PsiForeachStatement foreach = (PsiForeachStatement)variable.getParent();
+      PsiExpression iteratedValue = foreach.getIteratedValue();
+      return iteratedValue != null ? JavaGenericsUtil.getCollectionItemType(iteratedValue) : null;
+    }
+    else if (variable instanceof PsiParameter) {
+      PsiParameterList parameterList = ObjectUtils.tryCast(variable.getParent(), PsiParameterList.class);
+      if (parameterList == null) return null;
+      PsiLambdaExpression lambda = ObjectUtils.tryCast(parameterList.getParent(), PsiLambdaExpression.class);
+      if (lambda == null) return null;
+      PsiType functionalInterfaceType = lambda.getFunctionalInterfaceType();
+      if (functionalInterfaceType == null) return null;
+      ClassResolveResult resolveResult = PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
+      PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(resolveResult);
+      if (interfaceMethod == null) return null;
+      PsiParameter[] parameters = interfaceMethod.getParameterList().getParameters();
+      int index = parameterList.getParameterIndex((PsiParameter)variable);
+      if (index >= parameters.length) return null;
+      return LambdaUtil.getSubstitutor(interfaceMethod, resolveResult).substitute(parameters[index].getType());
+    }
+    else if (variable instanceof PsiLocalVariable) {
+      PsiExpression initializer = variable.getInitializer();
+      if (initializer == null) return null;
+      PsiType type = initializer.getType();
+      return PsiTypesUtil.isDenotableType(type, variable) && !PsiType.VOID.equals(type) ? type : null;
+    }
+    return null;
+  }
 }
@@ -0,0 +1,9 @@
+// "Set variable type to 'String'" "true"
+import java.util.List;
+
+class Demo {
+  void test(List<String> list) {
+    for (String s : list) {
+    }
+  }
+}
@@ -0,0 +1,9 @@
+// "Set variable type to 'HashMap<String, List<String>>'" "true"
+import java.util.HashMap;
+import java.util.List;
+
+class Demo {
+  void test() {
+    HashMap<String, List<String>> m = new HashMap<String, List<String>>();
+  }
+}
@@ -0,0 +1,11 @@
+// "Set variable type to 'FileInputStream'" "true"
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+
+class Demo {
+  void test() {
+    try (FileInputStream input = new FileInputStream("validation.txt")) {
+    } catch (FileNotFoundException e) {
+    }
+  }
+}
@@ -0,0 +1,9 @@
+// "Set variable type to 'String'" "true"
+import java.util.List;
+
+class Demo {
+  void test(List<String> list) {
+    for (var<caret> s : list) {
+    }
+  }
+}
@@ -0,0 +1,6 @@
+// "Set variable type to '<lambda expression>'" "false"
+class Demo {
+  void test() {
+    var<caret> s = () -> {};
+  }
+}
@@ -0,0 +1,8 @@
+// "Set variable type to '<lambda parameter>'" "false"
+class Demo {
+  void test() {
+    Object x = a -> {
+      var<caret> y = a;
+    };
+  }
+}
@@ -0,0 +1,9 @@
+// "Set variable type to 'HashMap<String, List<String>>'" "true"
+import java.util.HashMap;
+import java.util.List;
+
+class Demo {
+  void test() {
+    var<caret> m = new HashMap<String, List<String>>();
+  }
+}
@@ -0,0 +1,6 @@
+// "Set variable type to '<method reference>'" "false"
+class Demo {
+  void test() {
+    var<caret> s = this::foo;
+  }
+}
@@ -0,0 +1,6 @@
+// "Set variable type to 'null'" "false"
+class Demo {
+  void test() {
+    var<caret> s = null;
+  }
+}
@@ -0,0 +1,11 @@
+// "Set variable type to 'FileInputStream'" "true"
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+
+class Demo {
+  void test() {
+    try (var<caret> input = new FileInputStream("validation.txt")) {
+    } catch (FileNotFoundException e) {
+    }
+  }
+}
@@ -0,0 +1,8 @@
+// "Set variable type to 'void'" "false"
+public class Demo {
+  void test() {
+    var<caret> s = foo();
+  }
+
+  void foo() {}
+}
@@ -0,0 +1,21 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.java.codeInsight.daemon.quickFix;
+
+import com.intellij.codeInsight.daemon.quickFix.LightQuickFixParameterizedTestCase;
+import com.intellij.testFramework.LightProjectDescriptor;
+import com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase;
+import org.jetbrains.annotations.NotNull;
+
+public class SetExplicitTypeTest extends LightQuickFixParameterizedTestCase {
+
+  @Override
+  protected String getBasePath() {
+    return "/codeInsight/daemonCodeAnalyzer/quickFix/setExplicitType";
+  }
+
+  @Override
+  protected @NotNull LightProjectDescriptor getProjectDescriptor() {
+    return LightJavaCodeInsightFixtureTestCase.JAVA_9;
+  }
+}
+