From 2fc31d277f32ee3238cb963342eee971a0294d3a Mon Sep 17 00:00:00 2001
From: Timur <timurtibeyev@gmail.com>
Date: Thu, 27 Jul 2017 23:44:08 +0600
Subject: [PATCH] Issue #4422: Implement XpathFilter

---
 config/import-control.xml                     |   2 +
 config/pmd-test.xml                           |   3 +-
 .../tools/checkstyle/TreeWalker.java          |  18 +-
 .../checkstyle/TreeWalkerAuditEvent.java      |  23 +-
 .../tools/checkstyle/filters/XpathFilter.java | 184 ++++++++++++
 .../SuppressWithNearbyCommentFilterTest.java  |   6 +-
 .../filters/SuppressionCommentFilterTest.java |   8 +-
 .../checkstyle/filters/XpathFilterTest.java   | 268 ++++++++++++++++++
 .../filters/InputSuppressByXpath.java         |  18 ++
 9 files changed, 515 insertions(+), 15 deletions(-)
 create mode 100644 src/main/java/com/puppycrawl/tools/checkstyle/filters/XpathFilter.java
 create mode 100644 src/test/java/com/puppycrawl/tools/checkstyle/filters/XpathFilterTest.java
 create mode 100644 src/test/resources/com/puppycrawl/tools/checkstyle/filters/InputSuppressByXpath.java

diff --git a/config/import-control.xml b/config/import-control.xml
index 9b7fdb8706cb..d3fbe8e9a718 100644
--- a/config/import-control.xml
+++ b/config/import-control.xml
@@ -143,11 +143,13 @@
   </subpackage>
 
   <subpackage name="filters">
+    <allow pkg="net.sf.saxon"/>
     <allow class="java.lang.ref.WeakReference" local-only="true"/>
     <allow class="com.puppycrawl.tools.checkstyle.TreeWalkerAuditEvent" local-only="true"/>
     <allow class="com.puppycrawl.tools.checkstyle.TreeWalkerFilter" local-only="true"/>
     <disallow pkg="com\.puppycrawl\.tools\.checkstyle\.checks\.[^.]+" regex="true"/>
     <allow pkg="com.puppycrawl.tools.checkstyle.utils"/>
+    <allow pkg="com.puppycrawl.tools.checkstyle.xpath"/>
   </subpackage>
 
   <subpackage name="gui" strategyOnMismatch="disallowed">
diff --git a/config/pmd-test.xml b/config/pmd-test.xml
index e8b2303e8dbb..4c9dc37537d2 100644
--- a/config/pmd-test.xml
+++ b/config/pmd-test.xml
@@ -69,7 +69,7 @@
         <!-- pmd cannot find assert if it is located in private method of this class called from the test
         method or method of another class -->
         <properties>
-            <!-- in SuppressionCommentFilterTest, SuppressWithNearbyCommentFilterTest, SuppressionFilterTest
+            <!-- in SuppressionCommentFilterTest, SuppressWithNearbyCommentFilterTest, SuppressionFilterTest, XpathFilterTest
             pmd does not accept nl.jqno.equalsverifier.EqualsVerifier#.verify() as correctness check method -->
             <!-- in AbstractJavadocCheckTest pmd does not find asserts in another class methods called from the test method -->
             <!-- in ImportControlCheckTest, DetailASTTest
@@ -88,6 +88,7 @@
             | //ClassOrInterfaceDeclaration[@Image='AstRegressionTest']//MethodDeclarator[@Image='testImpossibleValid']
             | //ClassOrInterfaceDeclaration[@Image='AllChecksTest']//MethodDeclarator[@Image='testAllModulesAreReferencedInConfigFile']
             | //ClassOrInterfaceDeclaration[@Image='DetailASTTest']//MethodDeclarator[@Image='testTreeStructure']
+            | //ClassOrInterfaceDeclaration[@Image='XpathFilterTest']//MethodDeclarator[@Image='testEqualsAndHashCode']
             "/>
         </properties>
     </rule>
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
index a805de22c682..b633c39e334e 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
@@ -209,9 +209,14 @@ protected void processFiltered(File file, FileText fileText) throws CheckstyleEx
 
                         walk(astWithComments, contents, AstState.WITH_COMMENTS);
                     }
-                    final SortedSet<LocalizedMessage> filteredMessages =
-                            getFilteredMessages(fileName, contents);
-                    addMessages(filteredMessages);
+                    if (filters.isEmpty()) {
+                        addMessages(messages);
+                    }
+                    else {
+                        final SortedSet<LocalizedMessage> filteredMessages =
+                            getFilteredMessages(fileName, contents, rootAST);
+                        addMessages(filteredMessages);
+                    }
                     messages.clear();
                 }
             }
@@ -232,14 +237,15 @@ protected void processFiltered(File file, FileText fileText) throws CheckstyleEx
      * Returns filtered set of {@link LocalizedMessage}.
      * @param fileName path to the file
      * @param fileContents the contents of the file
+     * @param rootAST root AST element {@link DetailAST} of the file
      * @return filtered set of messages
      */
-    private SortedSet<LocalizedMessage> getFilteredMessages(String fileName,
-                                                            FileContents fileContents) {
+    private SortedSet<LocalizedMessage> getFilteredMessages(
+            String fileName, FileContents fileContents, DetailAST rootAST) {
         final SortedSet<LocalizedMessage> result = new TreeSet<>(messages);
         for (LocalizedMessage element : messages) {
             final TreeWalkerAuditEvent event =
-                    new TreeWalkerAuditEvent(fileContents, fileName, element);
+                    new TreeWalkerAuditEvent(fileContents, fileName, element, rootAST);
             for (TreeWalkerFilter filter : filters) {
                 if (!filter.accept(event)) {
                     result.remove(element);
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalkerAuditEvent.java b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalkerAuditEvent.java
index 00beac9c7e8c..629c680f6068 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalkerAuditEvent.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalkerAuditEvent.java
@@ -19,6 +19,7 @@
 
 package com.puppycrawl.tools.checkstyle;
 
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.FileContents;
 import com.puppycrawl.tools.checkstyle.api.LocalizedMessage;
 
@@ -34,6 +35,8 @@ public class TreeWalkerAuditEvent {
     private final FileContents fileContents;
     /** Message associated with the event. **/
     private final LocalizedMessage localizedMessage;
+    /** Root ast element. **/
+    private final DetailAST rootAst;
 
     /**
      * Creates a new {@code TreeWalkerAuditEvent} instance.
@@ -41,12 +44,14 @@ public class TreeWalkerAuditEvent {
      * @param fileContents contents of the file associated with the event
      * @param fileName file associated with the event
      * @param localizedMessage the actual message
+     * @param rootAst root AST element {@link DetailAST} of the file
      */
     public TreeWalkerAuditEvent(FileContents fileContents, String fileName,
-                                LocalizedMessage localizedMessage) {
+                                LocalizedMessage localizedMessage, DetailAST rootAst) {
         this.fileContents = fileContents;
         this.fileName = fileName;
         this.localizedMessage = localizedMessage;
+        this.rootAst = rootAst;
     }
 
     /**
@@ -115,4 +120,20 @@ public String getModuleId() {
     public String getSourceName() {
         return localizedMessage.getSourceName();
     }
+
+    /**
+     * Gets the token type of the message.
+     * @return the token type of the message
+     */
+    public int getTokenType() {
+        return localizedMessage.getTokenType();
+    }
+
+    /**
+     * Gets the root element of the AST tree.
+     * @return the root element of the AST tree
+     */
+    public DetailAST getRootAst() {
+        return rootAst;
+    }
 }
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/filters/XpathFilter.java b/src/main/java/com/puppycrawl/tools/checkstyle/filters/XpathFilter.java
new file mode 100644
index 000000000000..edede9dbeef4
--- /dev/null
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/filters/XpathFilter.java
@@ -0,0 +1,184 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.puppycrawl.tools.checkstyle.filters;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+import com.puppycrawl.tools.checkstyle.TreeWalkerAuditEvent;
+import com.puppycrawl.tools.checkstyle.TreeWalkerFilter;
+import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
+import com.puppycrawl.tools.checkstyle.xpath.AbstractNode;
+import com.puppycrawl.tools.checkstyle.xpath.RootNode;
+import net.sf.saxon.om.Item;
+import net.sf.saxon.sxpath.XPathDynamicContext;
+import net.sf.saxon.sxpath.XPathEvaluator;
+import net.sf.saxon.sxpath.XPathExpression;
+import net.sf.saxon.trans.XPathException;
+
+/**
+ * This filter processes {@link TreeWalkerAuditEvent}
+ * objects based on the criteria of file, check, module id, xpathQuery.
+ *
+ * @author Timur Tibeyev.
+ */
+public class XpathFilter implements TreeWalkerFilter {
+    /** The regexp to match file names against. */
+    private final Pattern fileRegexp;
+
+    /** The pattern for file names. */
+    private final String filePattern;
+
+    /** The regexp to match check names against. */
+    private final Pattern checkRegexp;
+
+    /** The pattern for check class names. */
+    private final String checkPattern;
+
+    /** Module id filter. */
+    private final String moduleId;
+
+    /** Xpath expression. */
+    private final XPathExpression xpathExpression;
+
+    /** Xpath query. */
+    private final String xpathQuery;
+
+    /**
+     * Creates a {@code XpathElement} instance.
+     * @param files regular expression for names of filtered files
+     * @param checks regular expression for filtered check classes
+     * @param moduleId the module id
+     * @param query the xpath query
+     */
+    public XpathFilter(String files, String checks,
+                       String moduleId, String query) {
+        filePattern = files;
+        fileRegexp = Pattern.compile(files);
+        checkPattern = checks;
+        if (checks == null) {
+            checkRegexp = null;
+        }
+        else {
+            checkRegexp = CommonUtils.createPattern(checks);
+        }
+        this.moduleId = moduleId;
+        xpathQuery = query;
+        if (xpathQuery == null) {
+            xpathExpression = null;
+        }
+        else {
+            final XPathEvaluator xpathEvaluator = new XPathEvaluator();
+            try {
+                xpathExpression = xpathEvaluator.createExpression(xpathQuery);
+            }
+            catch (XPathException ex) {
+                throw new IllegalStateException("Unexpected xpath query", ex);
+            }
+        }
+    }
+
+    @Override
+    public boolean accept(TreeWalkerAuditEvent event) {
+        return !isFileNameAndModuleAndCheckNameMatching(event)
+                || !isXpathQueryMatching(event);
+    }
+
+    /**
+     * Is matching by file name, moduleId and Check name.
+     * @param event event
+     * @return true if it is matching
+     */
+    private boolean isFileNameAndModuleAndCheckNameMatching(TreeWalkerAuditEvent event) {
+        return event.getFileName() != null
+                && fileRegexp.matcher(event.getFileName()).find()
+                && event.getLocalizedMessage() != null
+                && (moduleId == null || moduleId.equals(event.getModuleId()))
+                && (checkRegexp == null || checkRegexp.matcher(event.getSourceName()).find());
+    }
+
+    /**
+     * Is matching by xpath query.
+     * @param event event
+     * @return true is matching
+     */
+    private boolean isXpathQueryMatching(TreeWalkerAuditEvent event) {
+        boolean isMatching = false;
+        if (xpathExpression != null) {
+            final List<Item> items = getItems(event);
+            for (Item item : items) {
+                final AbstractNode abstractNode = (AbstractNode) item;
+                isMatching = abstractNode.getTokenType() == event.getTokenType()
+                        && abstractNode.getLineNumber() == event.getLine()
+                        && abstractNode.getColumnNumber() == event.getColumn();
+                if (isMatching) {
+                    break;
+                }
+            }
+        }
+        return isMatching;
+    }
+
+    /**
+     * Returns list of nodes matching xpath expression given event.
+     * @param event {@code TreeWalkerAuditEvent} object
+     * @return list of nodes matching xpath expression given event
+     */
+    private List<Item> getItems(TreeWalkerAuditEvent event) {
+        final RootNode rootNode;
+        if (event.getRootAst() == null) {
+            rootNode = null;
+        }
+        else {
+            rootNode = new RootNode(event.getRootAst());
+        }
+        final List<Item> items;
+        try {
+            final XPathDynamicContext xpathDynamicContext =
+                    xpathExpression.createDynamicContext(rootNode);
+            items = xpathExpression.evaluate(xpathDynamicContext);
+        }
+        catch (XPathException ex) {
+            throw new IllegalStateException(ex);
+        }
+        return items;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(filePattern, checkPattern, moduleId, xpathQuery);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (other == null || getClass() != other.getClass()) {
+            return false;
+        }
+        final XpathFilter xpathFilter = (XpathFilter) other;
+        return Objects.equals(filePattern, xpathFilter.filePattern)
+                && Objects.equals(checkPattern, xpathFilter.checkPattern)
+                && Objects.equals(moduleId, xpathFilter.moduleId)
+                && Objects.equals(xpathQuery, xpathFilter.xpathQuery);
+    }
+}
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressWithNearbyCommentFilterTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressWithNearbyCommentFilterTest.java
index 120daefb7822..7d05a9c97a01 100644
--- a/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressWithNearbyCommentFilterTest.java
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressWithNearbyCommentFilterTest.java
@@ -297,7 +297,7 @@ public void testInvalidCheckFormat() throws Exception {
     @Test
     public void testAcceptNullLocalizedMessage() {
         final SuppressWithNearbyCommentFilter filter = new SuppressWithNearbyCommentFilter();
-        final TreeWalkerAuditEvent auditEvent = new TreeWalkerAuditEvent(null, null, null);
+        final TreeWalkerAuditEvent auditEvent = new TreeWalkerAuditEvent(null, null, null, null);
         assertTrue("Filter should accept null localized message", filter.accept(auditEvent));
     }
 
@@ -353,13 +353,13 @@ public void testTagsAreClearedEachRun() {
                 new FileContents("filename", "//SUPPRESS CHECKSTYLE ignore", "line2");
         contents.reportSingleLineComment(1, 0);
         final TreeWalkerAuditEvent dummyEvent = new TreeWalkerAuditEvent(contents, "filename",
-                new LocalizedMessage(1, null, null, null, null, Object.class, null));
+                new LocalizedMessage(1, null, null, null, null, Object.class, null), null);
         suppressionCommentFilter.accept(dummyEvent);
         final FileContents contents2 =
                 new FileContents("filename2", "some line", "//SUPPRESS CHECKSTYLE ignore");
         contents2.reportSingleLineComment(2, 0);
         final TreeWalkerAuditEvent dummyEvent2 = new TreeWalkerAuditEvent(contents2, "filename",
-                new LocalizedMessage(1, null, null, null, null, Object.class, null));
+                new LocalizedMessage(1, null, null, null, null, Object.class, null), null);
         suppressionCommentFilter.accept(dummyEvent2);
         final List<SuppressionCommentFilter.Tag> tags =
                 Whitebox.getInternalState(suppressionCommentFilter, "tags");
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressionCommentFilterTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressionCommentFilterTest.java
index e27badac8c30..407efd78e604 100644
--- a/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressionCommentFilterTest.java
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/filters/SuppressionCommentFilterTest.java
@@ -297,7 +297,7 @@ public void testInvalidMessageFormat() throws Exception {
     @Test
     public void testAcceptNullLocalizedMessage() {
         final SuppressionCommentFilter filter = new SuppressionCommentFilter();
-        final TreeWalkerAuditEvent auditEvent = new TreeWalkerAuditEvent(null, null, null);
+        final TreeWalkerAuditEvent auditEvent = new TreeWalkerAuditEvent(null, null, null, null);
         Assert.assertTrue("Filter should accept audit event", filter.accept(auditEvent));
         Assert.assertNull("File name should not be null", auditEvent.getFileName());
     }
@@ -332,7 +332,7 @@ public void testFindNearestMatchDontAllowSameColumn() {
                 new FileContents("filename", "//CHECKSTYLE:OFF: ConstantNameCheck", "line2");
         contents.reportSingleLineComment(1, 0);
         final TreeWalkerAuditEvent dummyEvent = new TreeWalkerAuditEvent(contents, "filename",
-                new LocalizedMessage(1, null, null, null, null, Object.class, null));
+                new LocalizedMessage(1, null, null, null, null, Object.class, null), null);
         final boolean result = suppressionCommentFilter.accept(dummyEvent);
         assertFalse("Fileter should not accept event", result);
     }
@@ -344,13 +344,13 @@ public void testTagsAreClearedEachRun() {
                 new FileContents("filename", "//CHECKSTYLE:OFF", "line2");
         contents.reportSingleLineComment(1, 0);
         final TreeWalkerAuditEvent dummyEvent = new TreeWalkerAuditEvent(contents, "filename",
-                new LocalizedMessage(1, null, null, null, null, Object.class, null));
+                new LocalizedMessage(1, null, null, null, null, Object.class, null), null);
         suppressionCommentFilter.accept(dummyEvent);
         final FileContents contents2 =
                 new FileContents("filename2", "some line", "//CHECKSTYLE:OFF");
         contents2.reportSingleLineComment(2, 0);
         final TreeWalkerAuditEvent dummyEvent2 = new TreeWalkerAuditEvent(contents2, "filename",
-                new LocalizedMessage(1, null, null, null, null, Object.class, null));
+                new LocalizedMessage(1, null, null, null, null, Object.class, null), null);
         suppressionCommentFilter.accept(dummyEvent2);
         final List<SuppressionCommentFilter.Tag> tags =
                 Whitebox.getInternalState(suppressionCommentFilter, "tags");
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/filters/XpathFilterTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/filters/XpathFilterTest.java
new file mode 100644
index 000000000000..1efb3fc631b5
--- /dev/null
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/filters/XpathFilterTest.java
@@ -0,0 +1,268 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.puppycrawl.tools.checkstyle.filters;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.File;
+import java.nio.charset.StandardCharsets;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
+import com.puppycrawl.tools.checkstyle.TreeWalkerAuditEvent;
+import com.puppycrawl.tools.checkstyle.api.FileContents;
+import com.puppycrawl.tools.checkstyle.api.FileText;
+import com.puppycrawl.tools.checkstyle.api.LocalizedMessage;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+import com.puppycrawl.tools.checkstyle.internal.TestUtils;
+import net.sf.saxon.sxpath.XPathEvaluator;
+import net.sf.saxon.sxpath.XPathExpression;
+import nl.jqno.equalsverifier.EqualsVerifier;
+
+/** Tests XpathFilter Filter. */
+public class XpathFilterTest extends AbstractModuleTestSupport {
+
+    private File file;
+    private FileContents fileContents;
+
+    @Before
+    public void setUp() throws Exception {
+        file = new File(getPath("InputSuppressByXpath.java"));
+        fileContents = new FileContents(new FileText(file,
+                StandardCharsets.UTF_8.name()));
+    }
+
+    @Override
+    protected String getPackageLocation() {
+        return "com/puppycrawl/tools/checkstyle/filters";
+    }
+
+    @Test
+    public void testMatching() throws Exception {
+        final String xpath = "/CLASS_DEF[@text='InputSuppressByXpath']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 0,
+                TokenTypes.CLASS_DEF);
+        assertFalse("Event should be rejected", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingTokenType() throws Exception {
+        final String xpath = "//METHOD_DEF[@text='countTokens']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 0,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingLineNumber() throws Exception {
+        final String xpath = "/CLASS_DEF[@text='InputSuppressByXpath']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(100, 0,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingColumnNumber() throws Exception {
+        final String xpath = "/CLASS_DEF[@text='InputSuppressByXpath']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 100,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testComplexQuery() throws Exception {
+        final String xpath = "//VARIABLE_DEF[@text='pi' and "
+                + "../..[@text='countTokens']] "
+                + "| //VARIABLE_DEF[@text='someVariable' and ../..[@text='sum']]";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent eventOne = getEvent(5, 8,
+                TokenTypes.VARIABLE_DEF);
+        final TreeWalkerAuditEvent eventTwo = getEvent(10, 4,
+                TokenTypes.VARIABLE_DEF);
+        final TreeWalkerAuditEvent eventThree = getEvent(15, 8,
+                TokenTypes.VARIABLE_DEF);
+        assertFalse("Event should be rejected", filter.accept(eventOne));
+        assertTrue("Event should be accepted", filter.accept(eventTwo));
+        assertFalse("Event should be rejected", filter.accept(eventThree));
+    }
+
+    @Test
+    public void testIncorrectQuery() throws Exception {
+        final String xpath = "1@#";
+        try {
+            new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+            fail("Exception was expected");
+        }
+        catch (IllegalStateException ex) {
+            assertTrue("Message should be: Unexpected xpath query",
+                    ex.getMessage().contains("Unexpected xpath query"));
+        }
+    }
+
+    @Test
+    public void testNoQuery() throws Exception {
+        final TreeWalkerAuditEvent event = getEvent(15, 8,
+                TokenTypes.VARIABLE_DEF);
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, null);
+        assertTrue("Event should be accepted", filter.accept(event));
+    }
+
+    @Test
+    public void testNullFileName() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(null,
+                null, null, null);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingFileRegexp() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("NonMatchingRegexp", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 0,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNullLocalizedMessage() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(null,
+                file.getName(), null, null);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingModuleId() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", "id19", xpath);
+        final LocalizedMessage message =
+                new LocalizedMessage(3, 0, TokenTypes.CLASS_DEF, "", "", null, null, "id20",
+                        getClass(), null);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(fileContents,
+                file.getName(), message, TestUtils.parseFile(file));
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testMatchingModuleId() throws Exception {
+        final String xpath = "/CLASS_DEF[@text='InputSuppressByXpath']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", "id19", xpath);
+        final LocalizedMessage message =
+                new LocalizedMessage(3, 0, TokenTypes.CLASS_DEF, "", "", null, null, "id19",
+                        getClass(), null);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(fileContents,
+                file.getName(), message, TestUtils.parseFile(file));
+        assertFalse("Event should be rejected", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingChecks() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "NonMatchingRegexp", "id19", xpath);
+        final LocalizedMessage message =
+                new LocalizedMessage(3, 0, TokenTypes.CLASS_DEF, "", "", null, null, "id19",
+                        getClass(), null);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(fileContents,
+                file.getName(), message, TestUtils.parseFile(file));
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNonMatchingFileNameModuleIdAndCheck() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", null, null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 0,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testNullModuleIdAndNonMatchingChecks() throws Exception {
+        final String xpath = "NON_MATCHING_QUERY";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "NonMatchingRegexp", null, xpath);
+        final TreeWalkerAuditEvent ev = getEvent(3, 0,
+                TokenTypes.CLASS_DEF);
+        assertTrue("Event should be accepted", filter.accept(ev));
+    }
+
+    @Test
+    public void testThrowException() throws Exception {
+        final String xpath = "/CLASS_DEF[@text='InputSuppressByXpath']";
+        final XpathFilter filter =
+                new XpathFilter("InputSuppressByXpath", "Test", null, xpath);
+        final LocalizedMessage message =
+                new LocalizedMessage(3, 0, TokenTypes.CLASS_DEF, "", "", null, null, "id19",
+                        getClass(), null);
+        final TreeWalkerAuditEvent ev = new TreeWalkerAuditEvent(fileContents,
+                file.getName(), message, null);
+        try {
+            filter.accept(ev);
+        }
+        catch (IllegalStateException ex) {
+            assertTrue("Message should contain: net.sf.saxon.trans.XPathException",
+                    ex.getMessage().contains("net.sf.saxon.trans.XPathException"));
+        }
+    }
+
+    @Test
+    public void testEqualsAndHashCode() throws Exception {
+        final XPathEvaluator xpathEvaluator = new XPathEvaluator();
+        EqualsVerifier.forClass(XpathFilter.class).withPrefabValues(XPathExpression.class,
+                xpathEvaluator.createExpression("//METHOD_DEF"),
+                xpathEvaluator.createExpression("//VARIABLE_DEF"))
+                .usingGetClass()
+                .withIgnoredFields("fileRegexp", "checkRegexp", "xpathExpression")
+                .verify();
+    }
+
+    private TreeWalkerAuditEvent getEvent(int line, int column, int tokenType)
+            throws Exception {
+        final LocalizedMessage message =
+                new LocalizedMessage(line, column, tokenType, "", "", null, null, null,
+                        getClass(), null);
+        return new TreeWalkerAuditEvent(fileContents, file.getName(), message,
+                TestUtils.parseFile(file));
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/filters/InputSuppressByXpath.java b/src/test/resources/com/puppycrawl/tools/checkstyle/filters/InputSuppressByXpath.java
new file mode 100644
index 000000000000..334f82ca8a50
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/filters/InputSuppressByXpath.java
@@ -0,0 +1,18 @@
+package com.puppycrawl.tools.checkstyle.filters;
+
+public class InputSuppressByXpath {
+    private int countTokens() {
+        double pi = 3.14;
+        return 123;
+    }
+
+    public String getName() {
+        int someVariable = 123;
+        return "InputSuppressByXpathThree";
+    }
+
+    public int sum(int a, int b) {
+        String someVariable = "Hello World";
+        return a + b;
+    }
+}