content: /*
   * Copyright 2016 HuntBugs contributors
   * 
   * 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 one.util.huntbugs.detect;
  
  import java.util.stream.BaseStream;
  
  import com.strobel.assembler.metadata.MethodReference;
  import com.strobel.decompiler.ast.AstCode;
  import com.strobel.decompiler.ast.Expression;
  
  import one.util.huntbugs.flow.Inf;
  import one.util.huntbugs.registry.MethodContext;
  import one.util.huntbugs.registry.anno.AstNodes;
  import one.util.huntbugs.registry.anno.AstVisitor;
  import one.util.huntbugs.registry.anno.WarningDefinition;
  import one.util.huntbugs.util.Types;
  
  /**
   * @author lan
   *
   */
  @WarningDefinition(category="Correctness", name="AbandonedStream", maxScore=80)
  @WarningDefinition(category="BadPractice", name="StreamMethodMayNotReturnItself", maxScore=30)
  public class AbandonedStream {
      @AstVisitor(nodes=AstNodes.EXPRESSIONS, minVersion=8)
      public void visit(Expression expr, MethodContext mc) {
          if(expr.getCode() == AstCode.InvokeInterface) {
              MethodReference mr = (MethodReference) expr.getOperand();
              if(mr.getReturnType().getPackageName().equals("java.util.stream")
                      && Types.isBaseStream(mr.getReturnType())) {
                  // intermediate stream operation
                  if(mc.isAnnotated() && !Inf.BACKLINK.findTransitiveUsages(expr, true).findAny().isPresent()) {
                      // .parallel()/.sequential()/.onClose()/.unordered() excluded as may return itself
                      if(Types.is(mr.getReturnType(), BaseStream.class)) {
                          mc.report("StreamMethodMayNotReturnItself", 0, expr);
                      } else {
                          mc.report("AbandonedStream", 0, expr);
                      }
                  }
              }
          }
      }
  }
  