Issue #122: Added support for multiple instances of same check

Author: Anmol202005

.gitattributes

@@ -1,5 +1,8 @@
+# All files default to text with LF line endings
+* text eol=lf
+
+# Windows files always have CRLF eol
+*.cmd text eol=crlf
+
 # Test resources that need specific eol
 src/test/resources/org/checkstyle/autofix/recipe/newlineatendoffile/** -text
-
-# Force LF line endings for diff test files
-*.diff text eol=lf

config/pitest-suppressions.xml

@@ -460,6 +460,15 @@
     <lineContent>header = config.getProperty(HEADER_PROPERTY);</lineContent>
   </mutation>
 
+  <mutation unstable="false">
+    <sourceFile>Header.java</sourceFile>
+    <mutatedClass>org.checkstyle.autofix.recipe.Header</mutatedClass>
+    <mutatedMethod>extractLicenseHeader</mutatedMethod>
+    <mutator>org.pitest.mutationtest.engine.gregor.mutators.experimental.ArgumentPropagationMutator</mutator>
+    <description>replaced call to org/checkstyle/autofix/recipe/Header::toLfLineEnding with argument</description>
+    <lineContent>header = toLfLineEnding(Files.readString(Path.of(headerFilePath), charsetToUse));</lineContent>
+  </mutation>
+
   <mutation unstable="false">
     <sourceFile>Header.java</sourceFile>
     <mutatedClass>org.checkstyle.autofix.recipe.Header</mutatedClass>
@@ -487,6 +496,15 @@
     <lineContent>return &quot;Adds headers to Java source files when missing.&quot;;</lineContent>
   </mutation>
 
+  <mutation unstable="false">
+    <sourceFile>Header.java</sourceFile>
+    <mutatedClass>org.checkstyle.autofix.recipe.Header</mutatedClass>
+    <mutatedMethod>toLfLineEnding</mutatedMethod>
+    <mutator>org.pitest.mutationtest.engine.gregor.mutators.experimental.NakedReceiverMutator</mutator>
+    <description>replaced call to java/lang/String::replaceAll with receiver</description>
+    <lineContent>return text.replaceAll(&quot;(?x)\\\\r(?=\\\\n)|\\r(?=\\n)&quot;, &quot;&quot;);</lineContent>
+  </mutation>
+
   <mutation unstable="false">
     <sourceFile>Header.java</sourceFile>
     <mutatedClass>org.checkstyle.autofix.recipe.Header</mutatedClass>
@@ -505,13 +523,22 @@
     <lineContent>return violations.removeIf(violation -&gt; {</lineContent>
   </mutation>
 
+  <mutation unstable="false">
+    <sourceFile>Header.java</sourceFile>
+    <mutatedClass>org.checkstyle.autofix.recipe.Header$HeaderVisitor</mutatedClass>
+    <mutatedMethod>lambda$extractCurrentHeader$0</mutatedMethod>
+    <mutator>org.pitest.mutationtest.engine.gregor.mutators.experimental.ArgumentPropagationMutator</mutator>
+    <description>replaced call to org/checkstyle/autofix/recipe/Header::toLfLineEnding with argument</description>
+    <lineContent>+ toLfLineEnding(comment.getSuffix());</lineContent>
+  </mutation>
+
   <mutation unstable="false">
     <sourceFile>Header.java</sourceFile>
     <mutatedClass>org.checkstyle.autofix.recipe.Header$HeaderVisitor</mutatedClass>
     <mutatedMethod>lambda$extractCurrentHeader$0</mutatedMethod>
     <mutator>org.pitest.mutationtest.engine.gregor.mutators.NonVoidMethodCallMutator</mutator>
     <description>removed call to org/checkstyle/autofix/recipe/Header$HeaderVisitor::getCursor</description>
-    <lineContent>return comment.printComment(getCursor()) + comment.getSuffix();</lineContent>
+    <lineContent>return comment.printComment(getCursor())</lineContent>
   </mutation>
 
   <mutation unstable="false">
@@ -1303,7 +1330,7 @@
     <mutatedMethod>parseErrorTag</mutatedMethod>
     <mutator>org.pitest.mutationtest.engine.gregor.mutators.NonVoidMethodCallMutator</mutator>
     <description>removed call to java/util/Optional::empty</description>
-    <lineContent>Optional&lt;CheckstyleCheck&gt; source = Optional.empty();</lineContent>
+    <lineContent>Optional&lt;CheckstyleCheck&gt; check = Optional.empty();</lineContent>
   </mutation>
 
   <mutation unstable="false">
@@ -1312,7 +1339,7 @@
     <mutatedMethod>parseErrorTag</mutatedMethod>
     <mutator>org.pitest.mutationtest.engine.gregor.mutators.RemoveConditionalMutator_EQUAL_IF</mutator>
     <description>removed conditional - replaced equality check with true</description>
-    <lineContent>if (source.isPresent()) {</lineContent>
+    <lineContent>if (check.isPresent()) {</lineContent>
   </mutation>
 
   <mutation unstable="false">