Issue #2661: Enforce SingleSpaceSeparatorCheck of sevntu-checkstyle over Checkstyle source code

config/checkstyle_sevntu_checks.xml

@@ -52,5 +52,8 @@
             <property name="targetConstantTypes" value="LITERAL_NULL,LITERAL_TRUE,LITERAL_FALSE,NUM_INT,NUM_DOUBLE,NUM_LONG,NUM_FLOAT"/>
         </module>
         <module name="EitherLogOrThrowCheck"/>
+        <module name="SingleSpaceSeparator">
+            <metadata name="validateCommentNodes" value="false"/>
+        </module>
     </module>
 </module>

src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java

@@ -197,7 +197,7 @@ public abstract class AbstractTypeAwareCheck extends Check {
      */
     protected static boolean isSubclass(Class<?> child, Class<?> parent) {
         return parent != null && child != null
-            &&  parent.isAssignableFrom(child);
+            && parent.isAssignableFrom(child);
     }
 
     /**

src/main/java/com/puppycrawl/tools/checkstyle/checks/TranslationCheck.java

@@ -255,7 +255,7 @@ public class TranslationCheck
         boolean missing = false;
         for (File file : filesInResourceBundle) {
             final String currentFileName = file.getPath();
-            missing =  !currentFileName.equals(fileName);
+            missing = !currentFileName.equals(fileName);
             if (!missing) {
                 break;
             }

src/main/java/com/puppycrawl/tools/checkstyle/checks/design/MutableExceptionCheck.java

@@ -140,7 +140,7 @@ public final class MutableExceptionCheck extends Check {
                 ast.findFirstToken(TokenTypes.MODIFIERS);
 
             if (modifiersAST.findFirstToken(TokenTypes.FINAL) == null) {
-                log(ast.getLineNo(),  ast.getColumnNo(), MSG_KEY,
+                log(ast.getLineNo(), ast.getColumnNo(), MSG_KEY,
                         ast.findFirstToken(TokenTypes.IDENT).getText());
             }
         }

src/main/java/com/puppycrawl/tools/checkstyle/checks/design/ThrowsCountCheck.java

@@ -129,7 +129,7 @@ public final class ThrowsCountCheck extends Check {
             // Account for all the commas!
             final int count = (ast.getChildCount() + 1) / 2;
             if (count > max) {
-                log(ast.getLineNo(),  ast.getColumnNo(), MSG_KEY,
+                log(ast.getLineNo(), ast.getColumnNo(), MSG_KEY,
                     count, max);
             }
         }

src/main/java/com/puppycrawl/tools/checkstyle/checks/indentation/CommentsIndentationCheck.java

@@ -234,7 +234,7 @@ public class CommentsIndentationCheck extends Check {
                 destributed = true;
             }
         }
-        return  destributed;
+        return destributed;
     }
 
     /**

src/main/java/com/puppycrawl/tools/checkstyle/checks/naming/ConstantNameCheck.java

@@ -84,7 +84,7 @@ public class ConstantNameCheck
         final boolean isStatic = modifiersAST.branchContains(TokenTypes.LITERAL_STATIC);
         final boolean isFinal = modifiersAST.branchContains(TokenTypes.FINAL);
 
-        if (isStatic  && isFinal && shouldCheckInScope(modifiersAST)
+        if (isStatic && isFinal && shouldCheckInScope(modifiersAST)
                 || ScopeUtils.isInAnnotationBlock(ast)
                 || ScopeUtils.isInInterfaceOrAnnotationBlock(ast)
                         && !ScopeUtils.isInCodeBlock(ast)) {