[java-inspections] Support magic constants in case labels of switch statements and expressions

(IDEA-275706)

GitOrigin-RevId: e24c4410de35d120beeb2a8d5974dc3912b4ff9d

java/java-impl/src/com/intellij/codeInspection/magicConstant/MagicConstantInspection.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.codeInspection.magicConstant;
 
 import com.intellij.analysis.AnalysisScope;
@@ -135,6 +135,25 @@ public final class MagicConstantInspection extends AbstractBaseJavaLocalInspecti
         checkBinary(r, l);
       }
 
+      @Override
+      public void visitCaseLabelElementList(PsiCaseLabelElementList list) {
+        PsiSwitchBlock switchBlock = PsiTreeUtil.getParentOfType(list, PsiSwitchBlock.class);
+        if (switchBlock == null) return;
+        PsiExpression selector = switchBlock.getExpression();
+        PsiElement resolved = null;
+        if (selector instanceof PsiReference) {
+          resolved = ((PsiReference)selector).resolve();
+        }
+        else if (selector instanceof PsiMethodCallExpression) {
+          resolved = ((PsiCallExpression)selector).resolveMethod();
+        }
+        if (!(resolved instanceof PsiModifierListOwner)) return;
+        for (PsiCaseLabelElement element : list.getElements()) {
+          if (!(element instanceof PsiExpression)) continue;
+          checkExpression((PsiExpression)element, (PsiModifierListOwner)resolved, getType((PsiModifierListOwner)resolved), holder);
+        }
+      }
+
       private void checkBinary(@NotNull PsiExpression l, @NotNull PsiExpression r) {
         if (l instanceof PsiReference) {
           PsiElement resolved = ((PsiReference)l).resolve();

java/java-tests/testData/inspection/magic/SwitchBlock.java

@@ -0,0 +1,61 @@
+/*
+ * 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.
+ */
+
+import org.intellij.lang.annotations.MagicConstant;
+
+class Const1 {
+  public static final int X = 1;
+}
+
+class Const2 {
+  public static final int I = 4;
+}
+
+class X {
+  @MagicConstant(valuesFromClass = Const1.class, intValues = {Const2.I})
+  int foo() {
+    return Math.random() > 0.5 ? Const1.X : Const2.I;
+  }
+
+  void f(@MagicConstant(intValues = {Const1.X, Const2.I}) int x) {
+    /////////// BAD
+    switch (x) {
+      case <warning descr="Should be one of: Const1.X, Const2.I">0</warning>:
+        break;
+      case <warning descr="Should be one of: Const1.X, Const2.I">1</warning>:
+        break;
+      case <warning descr="Should be one of: Const1.X, Const2.I">Const1.X | Const2.I</warning>:
+        break;
+    }
+
+    switch (foo()) {
+      case <warning descr="Should be one of: Const2.I, Const1.X">0</warning>:
+        break;
+      case <warning descr="Should be one of: Const2.I, Const1.X">1</warning>:
+        break;
+      case <warning descr="Should be one of: Const2.I, Const1.X">Const1.X | Const2.I</warning>:
+        break;
+    }
+
+    /////////// GOOD
+    switch (x) {
+      case Const1.X:
+        break;
+      case Const2.I:
+        break;
+    }
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/MagicConstantInspectionTest.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 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.
- */
+// 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.codeInspection;
 
@@ -47,6 +33,7 @@ public class MagicConstantInspectionTest extends LightJavaCodeInsightFixtureTest
   public void testSpecialCases() { doTest(); }
   public void testVarargMethodCall() { doTest(); }
   public void testEnumConstructor() { doTest(); }
+  public void testSwitchBlock() { doTest(); }
 
   private void doTest() {
     myFixture.configureByFile(getTestName(false) + ".java");