Issue #3496: Enforce ReturnCount max=1 in com.puppycrawl.tools.checkstyle.checks and com.puppycrawl.tools.checkstyle

8 files changed, 72 insertions, 45 deletions

diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/JavadocDetailNodeParser.java b/src/main/java/com/puppycrawl/tools/checkstyle/JavadocDetailNodeParser.java
index cc70a7fe0..912803e2c 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/JavadocDetailNodeParser.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/JavadocDetailNodeParser.java
@@ -333,13 +333,15 @@ public class JavadocDetailNodeParser {
      * @return line number
      */
     private static int getLine(ParseTree tree) {
+        final int line;
         if (tree instanceof TerminalNode) {
-            return ((TerminalNode) tree).getSymbol().getLine() - 1;
+            line = ((TerminalNode) tree).getSymbol().getLine() - 1;
         }
         else {
             final ParserRuleContext rule = (ParserRuleContext) tree;
-            return rule.start.getLine() - 1;
+            line = rule.start.getLine() - 1;
         }
+        return line;
     }
 
     /**
@@ -349,13 +351,15 @@ public class JavadocDetailNodeParser {
      * @return column number
      */
     private static int getColumn(ParseTree tree) {
+        final int column;
         if (tree instanceof TerminalNode) {
-            return ((TerminalNode) tree).getSymbol().getCharPositionInLine();
+            column = ((TerminalNode) tree).getSymbol().getCharPositionInLine();
         }
         else {
             final ParserRuleContext rule = (ParserRuleContext) tree;
-            return rule.start.getCharPositionInLine();
+            column = rule.start.getCharPositionInLine();
         }
+        return column;
     }
 
     /**
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
index 7e2b5ceb5..3b98818ae 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
@@ -580,12 +580,14 @@ public final class TreeWalker extends AbstractFileSetCheck implements ExternalRe
      * @return true if position of ast1 is greater than position of ast2.
      */
     private static boolean isPositionGreater(DetailAST ast1, DetailAST ast2) {
+        final boolean isGreater;
         if (ast1.getLineNo() == ast2.getLineNo()) {
-            return ast1.getColumnNo() > ast2.getColumnNo();
+            isGreater = ast1.getColumnNo() > ast2.getColumnNo();
         }
         else {
-            return ast1.getLineNo() > ast2.getLineNo();
+            isGreater = ast1.getLineNo() > ast2.getLineNo();
         }
+        return isGreater;
     }
 
     /**
@@ -596,12 +598,14 @@ public final class TreeWalker extends AbstractFileSetCheck implements ExternalRe
      * @return DetailAST of comment node.
      */
     private static DetailAST createCommentAstFromToken(Token token) {
+        final DetailAST commentAst;
         if (token.getType() == TokenTypes.SINGLE_LINE_COMMENT) {
-            return createSlCommentNode(token);
+            commentAst = createSlCommentNode(token);
         }
         else {
-            return createBlockCommentNode(token);
+            commentAst = createBlockCommentNode(token);
         }
+        return commentAst;
     }
 
     /**
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractDeclarationCollector.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractDeclarationCollector.java
index 1ac51d551..3a32bae43 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractDeclarationCollector.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractDeclarationCollector.java
@@ -216,12 +216,11 @@ public abstract class AbstractDeclarationCollector extends AbstractCheck {
      * @return LexicalFrame containing declaration or null
      */
     private LexicalFrame findFrame(String name) {
-        if (current == null) {
-            return null;
-        }
-        else {
-            return current.getIfContains(name);
+        LexicalFrame frame = null;
+        if (current != null) {
+            frame = current.getIfContains(name);
         }
+        return frame;
     }
 
     /**
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java
index 344d03fa4..94c3f03c9 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java
@@ -231,12 +231,14 @@ public abstract class AbstractTypeAwareCheck extends AbstractCheck {
     // -@cs[ForbidWildcardAsReturnType] The class is deprecated and will be removed soon.
     protected final Class<?> resolveClass(String resolvableClassName,
             String className) {
+        Class<?> clazz;
         try {
-            return getClassResolver().resolve(resolvableClassName, className);
+            clazz = getClassResolver().resolve(resolvableClassName, className);
         }
         catch (final ClassNotFoundException ignored) {
-            return null;
+            clazz = null;
         }
+        return clazz;
     }
 
     /**
@@ -362,11 +364,15 @@ public abstract class AbstractTypeAwareCheck extends AbstractCheck {
      */
     protected final AbstractClassInfo createClassInfo(final Token name,
                                               final String surroundingClass) {
+        final AbstractClassInfo result;
         final AbstractClassInfo classInfo = findClassAlias(name.getText());
-        if (classInfo != null) {
-            return new ClassAlias(name, classInfo);
+        if (classInfo == null) {
+            result = new RegularClass(name, surroundingClass, this);
+        }
+        else {
+            result = new ClassAlias(name, classInfo);
         }
-        return new RegularClass(name, surroundingClass, this);
+        return result;
     }
 
     /**
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/LineSeparatorOption.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/LineSeparatorOption.java
index 31053eb98..8b03cedbd 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/LineSeparatorOption.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/LineSeparatorOption.java
@@ -65,16 +65,18 @@ public enum LineSeparatorOption {
      *     of this line separator
      */
     public boolean matches(byte... bytes) {
+        final boolean result;
         if (this == LF_CR_CRLF) {
             // this silently assumes CRLF and ANY have the same length
             // and LF and CR are of length 1
-            return CRLF.matches(bytes)
+            result = CRLF.matches(bytes)
                 || LF.matches(Arrays.copyOfRange(bytes, 1, 2))
                 || CR.matches(Arrays.copyOfRange(bytes, 1, 2));
         }
         else {
-            return Arrays.equals(bytes, lineSeparator);
+            result = Arrays.equals(bytes, lineSeparator);
         }
+        return result;
     }
 
     /**
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/NewlineAtEndOfFileCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/NewlineAtEndOfFileCheck.java
index d75944541..460c6e098 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/NewlineAtEndOfFileCheck.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/NewlineAtEndOfFileCheck.java
@@ -123,17 +123,21 @@ public class NewlineAtEndOfFileCheck
      */
     private boolean endsWithNewline(RandomAccessFile randomAccessFile)
             throws IOException {
+        final boolean result;
         final int len = lineSeparator.length();
         if (randomAccessFile.length() < len) {
-            return false;
+            result = false;
         }
-        randomAccessFile.seek(randomAccessFile.length() - len);
-        final byte[] lastBytes = new byte[len];
-        final int readBytes = randomAccessFile.read(lastBytes);
-        if (readBytes != len) {
-            throw new IOException("Unable to read " + len + " bytes, got "
-                    + readBytes);
+        else {
+            randomAccessFile.seek(randomAccessFile.length() - len);
+            final byte[] lastBytes = new byte[len];
+            final int readBytes = randomAccessFile.read(lastBytes);
+            if (readBytes != len) {
+                throw new IOException("Unable to read " + len + " bytes, got "
+                        + readBytes);
+            }
+            result = lineSeparator.matches(lastBytes);
         }
-        return lineSeparator.matches(lastBytes);
+        return result;
     }
 }
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/SuppressWarningsHolder.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/SuppressWarningsHolder.java
index b5eca8e8d..8dc6558e9 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/SuppressWarningsHolder.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/SuppressWarningsHolder.java
@@ -408,16 +408,18 @@ public class SuppressWarningsHolder
      * @throws IllegalArgumentException if the AST is invalid
      */
     private static String getIdentifier(DetailAST ast) {
-        if (ast != null) {
-            if (ast.getType() == TokenTypes.IDENT) {
-                return ast.getText();
-            }
-            else {
-                return getIdentifier(ast.getFirstChild()) + "."
-                        + getIdentifier(ast.getLastChild());
-            }
+        if (ast == null) {
+            throw new IllegalArgumentException("Identifier AST expected, but get null.");
+        }
+        final String identifier;
+        if (ast.getType() == TokenTypes.IDENT) {
+            identifier = ast.getText();
+        }
+        else {
+            identifier = getIdentifier(ast.getFirstChild()) + "."
+                + getIdentifier(ast.getLastChild());
         }
-        throw new IllegalArgumentException("Identifier AST expected, but get null.");
+        return identifier;
     }
 
     /**
@@ -457,17 +459,19 @@ public class SuppressWarningsHolder
      * @throws IllegalArgumentException if the AST is invalid
      */
     private static List<String> getAnnotationValues(DetailAST ast) {
+        final List<String> annotationValues;
         switch (ast.getType()) {
             case TokenTypes.EXPR:
-                return Collections.singletonList(getStringExpr(ast));
-
+                annotationValues = Collections.singletonList(getStringExpr(ast));
+                break;
             case TokenTypes.ANNOTATION_ARRAY_INIT:
-                return findAllExpressionsInChildren(ast);
-
+                annotationValues = findAllExpressionsInChildren(ast);
+                break;
             default:
                 throw new IllegalArgumentException(
                         "Expression or annotation array initializer AST expected: " + ast);
         }
+        return annotationValues;
     }
 
     /**
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/BaseCheckTestSupport.java b/src/test/java/com/puppycrawl/tools/checkstyle/BaseCheckTestSupport.java
index 0a5e6caa6..ae8d5995c 100644
--- a/src/test/java/com/puppycrawl/tools/checkstyle/BaseCheckTestSupport.java
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/BaseCheckTestSupport.java
@@ -400,12 +400,16 @@ public class BaseCheckTestSupport {
     }
 
     private static String getMessageBundle(String className) {
-        final int endIndex = className.lastIndexOf('.');
+        final String messageBundle;
         final String messages = "messages";
+        final int endIndex = className.lastIndexOf('.');
         if (endIndex < 0) {
-            return messages;
+            messageBundle = messages;
+        }
+        else {
+            final String packageName = className.substring(0, endIndex);
+            messageBundle = packageName + "." + messages;
         }
-        final String packageName = className.substring(0, endIndex);
-        return packageName + "." + messages;
+        return messageBundle;
     }
 }