Class SimplifyBooleanReturnCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.coding.SimplifyBooleanReturnCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class SimplifyBooleanReturnCheck
extends AbstractCheck

Checks for over-complicated boolean return or yield statements. For example the following code

if (valid())
  return false;
else
  return true;

could be written as

return !valid();

The idea for this Check has been shamelessly stolen from the equivalent PMD rule.

Since:

3.0

Nested Class Summary

Nested classes/interfaces inherited from class AbstractAutomaticBean

AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field	Description
static final String	MSG_KEY	A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor	Description
SimplifyBooleanReturnCheck()

Method Summary

Modifier and Type	Method	Description
private static boolean	canReturnOrYieldOnlyBooleanLiteral(DetailAST ast)	Returns if an AST is a return or a yield statement with a boolean literal or a compound statement that contains only such a return or a yield statement.
int[]	getAcceptableTokens()	The configurable token set.
int[]	getDefaultTokens()	Returns the default token a check is interested in.
int[]	getRequiredTokens()	The tokens that this check must be registered for.
private static boolean	isBooleanLiteralReturnOrYieldStatement(DetailAST ast)	Returns if an AST is a return or a yield statement with a boolean literal.
void	visitToken(DetailAST ast)	Called to process a token.

Methods inherited from class AbstractCheck

beginTree, clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

Methods inherited from class AbstractViolationReporter

finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity

Methods inherited from class AbstractAutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

MSG_KEY

public static final String MSG_KEY

A key is pointing to the warning message text in "messages.properties" file.

See Also:

• Constant Field Values

Constructor Details

SimplifyBooleanReturnCheck

public SimplifyBooleanReturnCheck()

Method Details

getAcceptableTokens

public int[] getAcceptableTokens()

Description copied from class: AbstractCheck

The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.

Specified by:

getAcceptableTokens in class AbstractCheck

Returns:

the token set this check is designed for.

See Also:

• TokenTypes

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: AbstractCheck

Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.

Specified by:

getDefaultTokens in class AbstractCheck

Returns:

the default tokens

See Also:

• TokenTypes

getRequiredTokens

public int[] getRequiredTokens()

Description copied from class: AbstractCheck

The tokens that this check must be registered for.

Specified by:

getRequiredTokens in class AbstractCheck

Returns:

the token set this must be registered for.

See Also:

• TokenTypes

visitToken

public void visitToken(DetailAST ast)

Description copied from class: AbstractCheck

Called to process a token.

Overrides:

visitToken in class AbstractCheck

Parameters:

ast - the token to process

canReturnOrYieldOnlyBooleanLiteral

private static boolean canReturnOrYieldOnlyBooleanLiteral(DetailAST ast)

Returns if an AST is a return or a yield statement with a boolean literal or a compound statement that contains only such a return or a yield statement.

Returns true iff ast represents

return/yield true/false;

or

{
  return/yield true/false;
}

Parameters:

ast - the syntax tree to check

Returns:

if ast is a return or a yield statement with a boolean literal.

isBooleanLiteralReturnOrYieldStatement

private static boolean isBooleanLiteralReturnOrYieldStatement(DetailAST ast)

Returns if an AST is a return or a yield statement with a boolean literal.

Returns true iff ast represents

return/yield true/false;

Parameters:

ast - the syntax tree to check

Returns:

if ast is a return or a yield statement with a boolean literal.