Fix quality flaw: Coverage on missing new line

Author: benzonico

.gitattributes

@@ -1 +1,2 @@
 java-frontend/src/test/files/highlighter/SonarSymTable.java eol=lf
+java-checks/src/test/files/checks/NonEmptyFile.java eol=cr

java-checks/src/main/java/org/sonar/java/checks/MissingNewLineAtEndOfFileCheck.java

@@ -21,33 +21,20 @@
 
 import org.sonar.check.Rule;
 import org.sonar.java.RspecKey;
-import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
+import org.sonar.plugins.java.api.JavaFileScanner;
 import org.sonar.plugins.java.api.JavaFileScannerContext;
-import org.sonar.plugins.java.api.tree.Tree;
-
-import java.util.Collections;
-import java.util.List;
 
 @Rule(key = "S00113")
 @RspecKey("S113")
-public class MissingNewLineAtEndOfFileCheck extends IssuableSubscriptionVisitor {
+public class MissingNewLineAtEndOfFileCheck implements JavaFileScanner {
 
-  @Override
-  public List<Tree.Kind> nodesToVisit() {
-    return Collections.emptyList();
-  }
 
   @Override
   public void scanFile(JavaFileScannerContext context) {
-    super.context = context;
     String content = context.getFileContent();
-    if(content.isEmpty()) {
-      return;
-    }
-
     char lastChar = content.charAt(content.length() - 1);
     if( lastChar != '\n' && lastChar != '\r') {
-      addIssueOnFile("Add a new line at the end of this file.");
+      context.addIssueOnFile(this, "Add a new line at the end of this file.");
     }
   }
 }

java-checks/src/test/files/checks/NonEmptyFile.java

@@ -1,2 +1 @@
-class NonEmptyFile {
-}
+class NonEmptyFile {}