[java-inspections] IDEA-264850 MagicConstant inspection does not work on varargs

GitOrigin-RevId: 4ac1cdc65c10fc40dec8ba5a3add52d12897526a

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

@@ -109,9 +109,20 @@ public final class MagicCompletionContributor extends CompletionContributor impl
         int i = ArrayUtil.indexOf(list.getExpressions(), argument);
         if (i == -1) continue;
         PsiParameter[] params = method.getParameterList().getParameters();
-        if (i >= params.length) continue;
-        PsiParameter parameter = params[i];
-        result.add(Pair.create(parameter, parameter.getType()));
+        PsiParameter parameter;
+        PsiType parameterType;
+        if (method.isVarArgs() && i >= params.length - 1) {
+          parameter = ArrayUtil.getLastElement(params);
+          parameterType = ((PsiEllipsisType)parameter.getType()).getComponentType();
+        }
+        else if (i < params.length) {
+          parameter = params[i];
+          parameterType = parameter.getType();
+        }
+        else {
+          continue;
+        }
+        result.add(Pair.create(parameter, parameterType));
       }
     }
     else if (IN_BINARY_COMPARISON.accepts(pos)) {

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

@@ -227,14 +227,22 @@ public final class MagicConstantInspection extends AbstractBaseJavaLocalInspecti
     PsiExpression[] arguments = argumentList.getExpressions();
     for (int i = 0; i < parameters.length; i++) {
       PsiParameter parameter = parameters[i];
-      AllowedValues values = MagicConstantUtils.getAllowedValues(parameter, parameter.getType());
+      PsiType type = parameter.getType();
+      int stopArg = i;
+      if (type instanceof PsiEllipsisType) {
+        type = ((PsiEllipsisType)type).getComponentType();
+        stopArg = arguments.length - 1;
+      }
+      AllowedValues values = MagicConstantUtils.getAllowedValues(parameter, type);
       if (values == null) continue;
       if (i >= arguments.length) break;
-      PsiExpression argument = arguments[i];
-      argument = PsiUtil.deparenthesizeExpression(argument);
-      if (argument == null) continue;
+      for (int j = i; j <= stopArg; j++) {
+        PsiExpression argument = arguments[j];
+        argument = PsiUtil.deparenthesizeExpression(argument);
+        if (argument == null) continue;
 
-      checkMagicParameterArgument(parameter, argument, values, holder);
+        checkMagicParameterArgument(parameter, argument, values, holder);
+      }
     }
   }
 

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

@@ -0,0 +1,31 @@
+/*
+ * 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;
+
+public class VarargMethodCall {
+  private static class Constants {
+    public static final int ONE = 1;
+    public static final int TWO = 2;
+  }
+  public static void testAnnotation1(@MagicConstant(valuesFromClass = Constants.class) int var0) {
+  }
+  public static void testAnnotation2(@MagicConstant(valuesFromClass = Constants.class) int... vars) {
+  }
+  public static void testMethod() {
+    testAnnotation1(<warning descr="Should be one of: Constants.ONE, Constants.TWO">1</warning>);
+    testAnnotation2(<warning descr="Should be one of: Constants.ONE, Constants.TWO">1</warning>, <warning descr="Should be one of: Constants.ONE, Constants.TWO">2</warning>);
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/MagicConstantCompletionTest.groovy

@@ -157,4 +157,54 @@ interface Foo {
     myFixture.complete(CompletionType.SMART)
     myFixture.assertPreferredCompletionItems 0, 'BAR', 'FOO'
   }
+
+  @NeedsIndex.ForStandardLibrary
+  void testVarargMethodCall() {
+    addMagicConstant()
+
+    @Language("JAVA")
+    def s = """
+import org.intellij.lang.annotations.MagicConstant;
+
+public class VarargMethodCall {
+  private static class Constants {
+    public static final int ONE = 1;
+    public static final int TWO = 2;
+  }
+  public static void testAnnotation2(@MagicConstant(valuesFromClass = Constants.class) int... vars) {
+  }
+  public static void testMethod() {
+    testAnnotation2(<caret>);
+  }
+}
+"""
+    myFixture.configureByText "a.java", s
+    myFixture.complete(CompletionType.SMART)
+    myFixture.assertPreferredCompletionItems 0, 'ONE', 'TWO'
+  }
+
+  @NeedsIndex.ForStandardLibrary
+  void testVarargMethodCall2() {
+    addMagicConstant()
+
+    @Language("JAVA")
+    def s = """
+import org.intellij.lang.annotations.MagicConstant;
+
+public class VarargMethodCall {
+  private static class Constants {
+    public static final int ONE = 1;
+    public static final int TWO = 2;
+  }
+  public static void testAnnotation2(@MagicConstant(valuesFromClass = Constants.class) int... vars) {
+  }
+  public static void testMethod() {
+    testAnnotation2(Constants.ONE, <caret>);
+  }
+}
+"""
+    myFixture.configureByText "a.java", s
+    myFixture.complete(CompletionType.SMART)
+    myFixture.assertPreferredCompletionItems 0, 'ONE', 'TWO'
+  }
 }

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

@@ -45,6 +45,7 @@ public class MagicConstantInspectionTest extends LightJavaCodeInsightFixtureTest
   // test that the optimisation for not loading AST works
   public void testWithLibrary() { doTest(); }
   public void testSpecialCases() { doTest(); }
+  public void testVarargMethodCall() { doTest(); }
 
   private void doTest() {
     myFixture.configureByFile(getTestName(false) + ".java");