IG: don't warn about unqualified static usage inside enum switch case (IDEA-209226)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/UnqualifiedStaticUsageInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2018 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2019 Dave Griffith, Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -179,26 +179,19 @@ public class UnqualifiedStaticUsageInspection extends BaseInspection implements
       registerError(expression, expression);
     }
 
-    private boolean isUnqualifiedStaticAccess(
-      PsiReferenceExpression expression) {
+    private boolean isUnqualifiedStaticAccess(PsiReferenceExpression expression) {
       if (m_ignoreStaticAccessFromStaticContext) {
-        final PsiMember member =
-          PsiTreeUtil.getParentOfType(expression,
-                                      PsiMember.class);
-        if (member != null &&
-            member.hasModifierProperty(PsiModifier.STATIC)) {
+        final PsiMember member = PsiTreeUtil.getParentOfType(expression, PsiMember.class);
+        if (member != null && member.hasModifierProperty(PsiModifier.STATIC)) {
           return false;
         }
       }
-      final PsiExpression qualifierExpression =
-        expression.getQualifierExpression();
+      final PsiExpression qualifierExpression = expression.getQualifierExpression();
       if (qualifierExpression != null) {
         return false;
       }
-      final JavaResolveResult resolveResult =
-        expression.advancedResolve(false);
-      final PsiElement currentFileResolveScope =
-        resolveResult.getCurrentFileResolveScope();
+      final JavaResolveResult resolveResult = expression.advancedResolve(false);
+      final PsiElement currentFileResolveScope = resolveResult.getCurrentFileResolveScope();
       if (currentFileResolveScope instanceof PsiImportStaticStatement) {
         return false;
       }
@@ -208,9 +201,11 @@ public class UnqualifiedStaticUsageInspection extends BaseInspection implements
         return false;
       }
       final PsiMember member = (PsiMember)element;
-      if (member instanceof PsiEnumConstant &&
-          expression.getParent() instanceof PsiSwitchLabelStatement) {
-        return false;
+      if (member instanceof PsiEnumConstant) {
+        PsiElement parent = expression.getParent();
+        if (parent instanceof PsiExpressionList && parent.getParent() instanceof PsiSwitchLabelStatementBase) {
+          return false;
+        }
       }
       return member.hasModifierProperty(PsiModifier.STATIC);
     }

plugins/InspectionGadgets/test/com/siyeh/igtest/style/unqualified_static_usage/UnqualifiedStaticUsage.java

@@ -0,0 +1,17 @@
+enum UnqualifiedStaticUsage {
+  RED, BLUE;
+
+  int switches(UnqualifiedStaticUsage c) {
+    System.out.println(<warning descr="Unqualified static field access 'RED'">RED</warning>);
+    System.out.println(UnqualifiedStaticUsage.BLUE);
+    switch (c) {
+      case RED: break;
+      case BLUE: break;
+    }
+    return switch (c) {
+      case RED -> 1;
+      case BLUE -> 2;
+    };
+  }
+}
+

plugins/InspectionGadgets/testsrc/com/siyeh/ig/style/UnqualifiedStaticUsageInspectionTest.java

@@ -0,0 +1,32 @@
+// Copyright 2000-2019 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.
+package com.siyeh.ig.style;
+
+import com.intellij.codeInspection.InspectionProfileEntry;
+import com.intellij.testFramework.LightPlatformCodeInsightTestCase;
+import com.intellij.testFramework.LightProjectDescriptor;
+import com.siyeh.ig.LightInspectionTestCase;
+import junit.framework.TestCase;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class UnqualifiedStaticUsageInspectionTest extends LightInspectionTestCase {
+
+  public void testUnqualifiedStaticUsage() {
+    doTest();
+  }
+
+  @Nullable
+  @Override
+  protected InspectionProfileEntry getInspection() {
+    return new UnqualifiedStaticUsageInspection();
+  }
+
+  @NotNull
+  @Override
+  protected LightProjectDescriptor getProjectDescriptor() {
+    return JAVA_12;
+  }
+}