Issue #3488: save files into cache with no un-suppressed violations

src/main/java/com/puppycrawl/tools/checkstyle/Checker.java

@@ -271,13 +271,13 @@ public class Checker extends AutomaticBean implements MessageDispatcher, RootMod
                         || !acceptFileStarted(fileName)) {
                     continue;
                 }
+                if (cache != null) {
+                    cache.put(fileName, timestamp);
+                }
                 fireFileStarted(fileName);
                 final SortedSet<LocalizedMessage> fileMessages = processFile(file);
                 fireErrors(fileName, fileMessages);
                 fireFileFinished(fileName);
-                if (cache != null && fileMessages.isEmpty()) {
-                    cache.put(fileName, timestamp);
-                }
             }
             // -@cs[IllegalCatch] There is no other way to deliver filename that was under
             // processing. See https://github.com/checkstyle/checkstyle/issues/2285
@@ -352,14 +352,19 @@ public class Checker extends AutomaticBean implements MessageDispatcher, RootMod
     @Override
     public void fireErrors(String fileName, SortedSet<LocalizedMessage> errors) {
         final String stripped = CommonUtils.relativizeAndNormalizePath(basedir, fileName);
+        boolean hasNonFilteredViolations = false;
         for (final LocalizedMessage element : errors) {
             final AuditEvent event = new AuditEvent(this, stripped, element);
             if (filters.accept(event)) {
+                hasNonFilteredViolations = true;
                 for (final AuditListener listener : listeners) {
                     listener.addError(event);
                 }
             }
         }
+        if (hasNonFilteredViolations && cache != null) {
+            cache.remove(fileName);
+        }
     }
 
     /**

src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java

@@ -200,6 +200,14 @@ final class PropertyCacheFile {
         return details.getProperty(name);
     }
 
+    /**
+     * Removed a specific file from the cache.
+     * @param checkedFileName The name of the file to remove.
+     */
+    public void remove(String checkedFileName) {
+        details.remove(checkedFileName);
+    }
+
     /**
      * Calculates the hashcode for the serializable object based on its content.
      * @param object serializable object.

src/test/java/com/puppycrawl/tools/checkstyle/CheckerTest.java

@@ -22,12 +22,14 @@ package com.puppycrawl.tools.checkstyle;
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.Mockito.when;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOError;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
@@ -36,6 +38,7 @@ import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Properties;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
@@ -740,6 +743,38 @@ public class CheckerTest extends BaseCheckTestSupport {
         verify(checker, filePath, filePath, expected);
     }
 
+    @Test
+    public void testCacheOnViolationSuppression() throws Exception {
+        final File cacheFile = temporaryFolder.newFile();
+        final DefaultConfiguration violationCheck =
+                createCheckConfig(DummyFileSetViolationCheck.class);
+        final DefaultConfiguration defaultConfig = new DefaultConfiguration("defaultConfiguration");
+        defaultConfig.addAttribute("cacheFile", cacheFile.getPath());
+        defaultConfig.addChild(violationCheck);
+
+        final DefaultConfiguration filterConfig = createCheckConfig(SuppressionFilter.class);
+        filterConfig.addAttribute("file", getPath("suppress_all.xml"));
+        defaultConfig.addChild(filterConfig);
+
+        final Checker checker = new Checker();
+        checker.setModuleClassLoader(Thread.currentThread().getContextClassLoader());
+        checker.addListener(new BriefUtLogger(stream));
+        checker.configure(defaultConfig);
+
+        final String fileViolationPath = temporaryFolder.newFile("ViolationFile.java").getPath();
+        final String[] expected = CommonUtils.EMPTY_STRING_ARRAY;
+
+        verify(checker, fileViolationPath, expected);
+
+        try (FileInputStream input = new FileInputStream(cacheFile)) {
+            final Properties details = new Properties();
+            details.load(input);
+
+            assertNotNull("suppressed violation file saved in cache",
+                    details.getProperty(fileViolationPath));
+        }
+    }
+
     private Checker createMockCheckerWithCacheForModule(
         Class<? extends ExternalResourceHolder> mockClass) throws IOException, CheckstyleException {
 
@@ -778,6 +813,22 @@ public class CheckerTest extends BaseCheckTestSupport {
         }
     }
 
+    private static class DummyFileSetViolationCheck extends AbstractFileSetCheck
+        implements ExternalResourceHolder {
+
+        @Override
+        protected void processFiltered(File file, List<String> lines) throws CheckstyleException {
+            log(0, "test");
+        }
+
+        @Override
+        public Set<String> getExternalResourceLocations() {
+            final Set<String> externalResourceLocation = new HashSet<>(1);
+            externalResourceLocation.add("non_existing_external_resource.xml");
+            return externalResourceLocation;
+        }
+    }
+
     private static class MockMissingExternalResourcesFileSetCheck extends AbstractFileSetCheck
         implements ExternalResourceHolder {
 

src/test/resources/com/puppycrawl/tools/checkstyle/suppress_all.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+    "-//Puppy Crawl//DTD Suppressions 1.1//EN"
+    "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
+
+<suppressions>
+    <suppress checks="." files="."/>
+</suppressions>