AutoCloseableResourceInspection: warning on Files.lines,...: IDEA-182784

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/InspectionGadgetsBundle.properties

@@ -1757,6 +1757,7 @@ logger.class.name=Logger class name
 ignore.exceptions.declared.on.library.override.option=Ignore exceptions declared on methods overriding a &library method
 allow.resource.to.be.opened.inside.a.try.block=Allow resource to be opened inside a 'try' block
 any.method.may.close.resource.argument=Any method may close resource argument
+show.warning.for.stream.holding.resource=Show warning for java.util.Stream holding resource
 log.method.name=Logging method name
 log.condition.text=Log condition text
 ignore.if.annotated.by=Ignore if annotated by

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/resources/AutoCloseableResourceInspectionBase.java

@@ -42,6 +42,8 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import static com.intellij.util.ObjectUtils.tryCast;
+
 /**
  * @author Bas Leijdekkers
  */
@@ -54,6 +56,8 @@ public class AutoCloseableResourceInspectionBase extends ResourceInspection {
   @SuppressWarnings("PublicField")
   public boolean ignoreFromMethodCall = false;
 
+  public boolean showWarningForStreamHoldingResource = true;
+
   final List<String> ignoredTypes = new ArrayList<>(DEFAULT_IGNORED_TYPES);
   protected final MethodMatcher myMethodMatcher;
 
@@ -67,6 +71,8 @@ public class AutoCloseableResourceInspectionBase extends ResourceInspection {
       .finishDefault();
   }
 
+  CallMatcher STREAM_HOLDING_RESOURCE = CallMatcher.staticCall("java.nio.file.Files",  "lines", "walk", "list", "find");
+
   @Nls
   @NotNull
   @Override
@@ -148,7 +154,12 @@ public class AutoCloseableResourceInspectionBase extends ResourceInspection {
   @Override
   protected boolean isResourceCreation(PsiExpression expression) {
     return TypeUtils.expressionHasTypeOrSubtype(expression, CommonClassNames.JAVA_LANG_AUTO_CLOSEABLE) &&
-           !TypeUtils.expressionHasTypeOrSubtype(expression, ignoredTypes);
+           (isStreamHoldingResource(expression)
+            || !TypeUtils.expressionHasTypeOrSubtype(expression, ignoredTypes));
+  }
+
+  private boolean isStreamHoldingResource(PsiExpression expression) {
+    return showWarningForStreamHoldingResource && STREAM_HOLDING_RESOURCE.matches(tryCast(expression, PsiMethodCallExpression.class));
   }
 
   @Override
@@ -178,7 +189,7 @@ public class AutoCloseableResourceInspectionBase extends ResourceInspection {
       if (ignoreFromMethodCall || myMethodMatcher.matches(expression) || isSafelyClosedResource(expression)) {
         return;
       }
-      registerMethodCallError(expression, expression.getType(), Boolean.TRUE);
+      registerMethodCallError(expression, expression.getType(), !isStreamHoldingResource(expression));
     }
 
     @Override

plugins/InspectionGadgets/src/com/siyeh/ig/resources/AutoCloseableResourceInspection.java

@@ -64,6 +64,7 @@ public class AutoCloseableResourceInspection extends AutoCloseableResourceInspec
     checkBox.addChangeListener(e -> table2.setEnabled(!ignoreFromMethodCall));
     panel.add(checkBox);
     panel.add(new CheckBox(InspectionGadgetsBundle.message("any.method.may.close.resource.argument"), this, "anyMethodMayClose"));
+    panel.add(new CheckBox(InspectionGadgetsBundle.message("show.warning.for.stream.holding.resource"), this, "showWarningForStreamHoldingResource"));
     return panel;
   }
 }

plugins/InspectionGadgets/testsrc/com/siyeh/ig/resources/AutoCloseableResourceInspectionTest.java

@@ -16,7 +16,9 @@
 package com.siyeh.ig.resources;
 
 import com.intellij.codeInspection.LocalInspectionTool;
+import com.intellij.testFramework.LightProjectDescriptor;
 import com.siyeh.ig.LightInspectionTestCase;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author Bas Leijdekkers
@@ -74,6 +76,7 @@ public class AutoCloseableResourceInspectionTest extends LightInspectionTestCase
   }
 
   public void testARM() {
+    mockSql();
     doTest("import java.sql.*;\n" +
            "class X {\n" +
            "  void m(Driver driver) throws SQLException {\n" +
@@ -81,12 +84,29 @@ public class AutoCloseableResourceInspectionTest extends LightInspectionTestCase
            "      PreparedStatement statement = connection.prepareStatement(\"SELECT *\");\n" +
            "      ResultSet resultSet = statement.executeQuery()) {\n" +
            "      while (resultSet.next()) { resultSet.getMetaData(); }\n" +
-           "    }\n" +
+           "    } catch(Exception e) {}\n" +
            "  }\n" +
            "}");
   }
 
+  private void mockSql() {
+    addEnvironmentClass("package java.sql;\n" +
+                        "public interface Driver { Connection connect(String s, Object o) throws SQLException;}");
+    addEnvironmentClass("package java.sql;\n" +
+                        "public interface Connection extends AutoCloseable { PreparedStatement prepareStatement(String s);}");
+    addEnvironmentClass("package java.sql;\n" +
+                        "public interface PreparedStatement extends AutoCloseable { ResultSet executeQuery();}");
+    addEnvironmentClass("package java.sql;\n" +
+                        "public class SQLException extends Exception {}");
+    addEnvironmentClass("package java.sql;\n" +
+                        "public interface ResultSet extends AutoCloseable {\n" +
+                        "  boolean next();\n" +
+                        "  void getMetaData();\n" +
+                        "}");
+  }
+
   public void testSimple() {
+    mockSql();
     doTest("import java.sql.*;" +
            "class X {" +
            "  void m(Driver driver) throws SQLException {" +
@@ -163,6 +183,28 @@ public class AutoCloseableResourceInspectionTest extends LightInspectionTestCase
            "}");
   }
 
+  @NotNull
+  @Override
+  protected LightProjectDescriptor getProjectDescriptor() {
+    return JAVA_8;
+  }
+
+  public void testFilesMethod() {
+    addEnvironmentClass("package java.nio.file;\n" +
+                        "import java.util.stream.Stream;\n" +
+                        "public final class Files {\n" +
+                        "  public static Stream<String> lines(Path path) {return Stream.empty();}\n" +
+                        "}");
+    doTest("import java.io.*;\n" +
+           "import java.nio.file.Files;\n" +
+           "import java.util.stream.Stream;\n" +
+           "class X {\n" +
+           "  private static void example(int a)  {\n" +
+           "    Stream<String> s = Files.<warning descr=\"'Stream<String>' used without 'try'-with-resources statement\">lines</warning>(null);\n" +
+           "  }\n" +
+           "}");
+  }
+
   public void testClosedResource() {
     doTest("import java.io.*;\n" +
            "\n" +