plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/redundancy/ElementOnlyUsedFromTestCodeInspection.java

/*
 * Copyright 2011 Bas Leijdekkers
 *
 * 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.
 */
package com.siyeh.ig.redundancy;

import com.intellij.analysis.AnalysisScope;
import com.intellij.codeInsight.TestFrameworks;
import com.intellij.codeInspection.*;
import com.intellij.codeInspection.reference.*;
import com.intellij.openapi.roots.ProjectRootManager;
import com.intellij.openapi.util.Key;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.psi.*;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseGlobalInspection;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

public class ElementOnlyUsedFromTestCodeInspection
  extends BaseGlobalInspection {

  private static final Key<Boolean> ONLY_USED_FROM_TEST_CODE =
    Key.create("ONLY_USED_FROM_TEST_CODE");

  @NotNull
  @Override
  public String getDisplayName() {
    return InspectionGadgetsBundle.message(
      "element.only.used.from.test.code.display.name");
  }

  @Override
  @Nullable
  public RefGraphAnnotator getAnnotator(@NotNull RefManager refManager) {
    return new ElementOnlyUsedFromTestCodeAnnotator();
  }

  @Nullable
  @Override
  public CommonProblemDescriptor[] checkElement(
    @NotNull RefEntity refEntity, @NotNull AnalysisScope scope, @NotNull InspectionManager manager,
    @NotNull GlobalInspectionContext globalContext,
    @NotNull ProblemDescriptionsProcessor processor) {
    if (!isOnlyUsedFromTestCode(refEntity)) {
      return null;
    }
    if (!(refEntity instanceof RefJavaElement)) {
      return null;
    }
    final RefJavaElement javaElement = (RefJavaElement)refEntity;
    if (!javaElement.isReferenced()) {
      return null;
    }
    final PsiElement element = javaElement.getElement();
    if (element instanceof PsiClass) {
      final PsiClass aClass = (PsiClass)element;
      final PsiIdentifier identifier = aClass.getNameIdentifier();
      if (identifier == null) {
        return null;
      }
      return new CommonProblemDescriptor[]{
        manager.createProblemDescriptor(identifier,
                                        InspectionGadgetsBundle.message(
                                          "class.only.used.from.test.code.problem.descriptor"),
                                        true, ProblemHighlightType.GENERIC_ERROR_OR_WARNING, false)
      };
    }
    else if (element instanceof PsiMethod) {
      final PsiMethod method = (PsiMethod)element;
      final PsiIdentifier identifier = method.getNameIdentifier();
      if (identifier == null) {
        return null;
      }
      return new CommonProblemDescriptor[]{
        manager.createProblemDescriptor(identifier,
                                        InspectionGadgetsBundle.message(
                                          "method.only.used.from.test.code.problem.descriptor"),
                                        true, ProblemHighlightType.GENERIC_ERROR_OR_WARNING, false)
      };
    }
    else if (element instanceof PsiField) {
      final PsiField field = (PsiField)element;
      final PsiIdentifier identifier = field.getNameIdentifier();
      return new CommonProblemDescriptor[]{
        manager.createProblemDescriptor(identifier,
                                        InspectionGadgetsBundle.message(
                                          "field.only.used.from.test.code.problem.descriptor"),
                                        true, ProblemHighlightType.GENERIC_ERROR_OR_WARNING, false)
      };
    }
    return null;
  }

  private static boolean isInsideTestClass(@NotNull PsiElement e) {
    final PsiClass aClass = getTopLevelParentClass(e);
    return aClass != null && TestFrameworks.getInstance().isTestClass(aClass);
  }

  private static boolean isUnderTestSources(PsiElement e) {
    final ProjectRootManager rootManager =
      ProjectRootManager.getInstance(e.getProject());
    final VirtualFile file = e.getContainingFile().getVirtualFile();
    return file != null &&
           rootManager.getFileIndex().isInTestSourceContent(file);
  }

  @Nullable
  public static PsiClass getTopLevelParentClass(PsiElement e) {
    PsiClass result = null;
    PsiElement parent = e.getParent();
    while (parent != null && !(parent instanceof PsiFile)) {
      if (parent instanceof PsiClass) {
        result = (PsiClass)parent;
      }
      parent = parent.getParent();
    }
    return result;
  }

  private static boolean isOnlyUsedFromTestCode(RefEntity refElement) {
    final Boolean usedFromTestCode =
      refElement.getUserData(ONLY_USED_FROM_TEST_CODE);
    return usedFromTestCode != null && usedFromTestCode.booleanValue();
  }

  private static class ElementOnlyUsedFromTestCodeAnnotator
    extends RefGraphAnnotator {

    @Override
    public void onMarkReferenced(RefElement refWhat, RefElement refFrom,
                                 boolean referencedFromClassInitializer) {
      if (!(refWhat instanceof RefMethod) &&
          !(refWhat instanceof RefField) &&
          !(refWhat instanceof RefClass)) {
        return;
      }
      if (referencedFromClassInitializer ||
          refFrom instanceof RefImplicitConstructor) {
        return;
      }
      final PsiElement whatElement = refWhat.getElement();
      if (isInsideTestClass(whatElement) ||
          isUnderTestSources(whatElement)) {
        // test code itself is allowed to only be used from test code
        return;
      }
      if (refFrom instanceof RefMethod && refWhat instanceof RefClass) {
        final RefMethod method = (RefMethod)refFrom;
        if (method.isConstructor() &&
            method.getOwnerClass() == refWhat) {
          // don't count references to class from its own constructor
          return;
        }
      }
      final Boolean onlyUsedFromTestCode =
        refWhat.getUserData(ONLY_USED_FROM_TEST_CODE);
      if (onlyUsedFromTestCode == null) {
        refWhat.putUserData(ONLY_USED_FROM_TEST_CODE, Boolean.TRUE);
      }
      else if (!onlyUsedFromTestCode.booleanValue()) {
        return;
      }
      final PsiElement fromElement = refFrom.getElement();
      if (isInsideTestClass(fromElement) ||
          isUnderTestSources(fromElement)) {
        return;
      }

      if (refWhat instanceof RefMethod) {
        final RefMethod what = (RefMethod)refWhat;
        if (what.isConstructor()) {
          final RefClass ownerClass = what.getOwnerClass();
          ownerClass.putUserData(ONLY_USED_FROM_TEST_CODE,
                                 Boolean.FALSE);
          // do count references to class from its own constructor
          // when that constructor is used outside of test code.
        }
      }
      refWhat.putUserData(ONLY_USED_FROM_TEST_CODE, Boolean.FALSE);
    }
  }
}