com.github.sevntu.checkstyle.checks.coding

Class ReturnCountExtendedCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.github.sevntu.checkstyle.checks.coding.ReturnCountExtendedCheck

All Implemented Interfaces:

com.puppycrawl.tools.checkstyle.api.Configurable, com.puppycrawl.tools.checkstyle.api.Contextualizable

public class ReturnCountExtendedCheck
extends com.puppycrawl.tools.checkstyle.api.AbstractCheck

Checks that method/ctor "return" literal count is not greater than the given value ("maxReturnCount" property).

Rationale:

One return per method is a good practice as its ease understanding of method logic.

Reasoning is that:

• It is easier to understand control flow when you know exactly where the method returns.
• Methods with 2-3 or many "return" statements are much more difficult to understand, debug and refactor.

Setting up the check options will make it to ignore:

1. Methods by name ("ignoreMethodsNames" property). Note, that the "ignoreMethodsNames" property type is a RegExp: using this property you can list the names of ignored methods separated by comma (but you can also use '|' to separate different method names in usual for RegExp style). If the violation is on a lambda, since it has no method name, you can specify the string null to ignore all lambda violations for now. It should be noted, that ignoring lambdas this way may not always be supported as it is a hack and giving all lambdas the same name. It could be changed if a better way to single out individual lambdas if found.
2. Methods which linelength less than given value ("linesLimit" property).
3. "return" statements which depth is greater or equal to the given value ("returnDepthLimit" property). There are few supported
   coding blocks when depth counting: "if-else", "for", "while"/"do-while" and "switch".
4. "Empty" return statements = return statements in void methods and ctors that have not any expression ("ignoreEmptyReturns" property).
5. Return statements, which are located in the top lines of method/ctor (you can specify the count of top method/ctor lines that will be ignored using "rowsToIgnoreCount" property).

So, this is much improved version of the existing ReturnCountCheck.

Since:

1.8.0

Author:

Daniil Yaroslavtsev

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AutomaticBean.OutputStreamOptions

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
ReturnCountExtendedCheck() Creates the new check instance.

Method Summary

Modifier and Type	Method and Description
int[]	getAcceptableTokens()
int[]	getDefaultTokens()
int[]	getRequiredTokens()
void	setIgnoreEmptyReturns(boolean ignoreEmptyReturns) Sets the "ignoring empty return statements in void methods and ctors and lambdas" option state.
void	setIgnoreMethodLinesCount(int ignoreMethodLinesCount) Sets the maximum number of lines of which method/ctor/lambda body may consist to be skipped by check.
void	setIgnoreMethodsNames(String... ignoreMethodNames) Sets the RegExp patterns for methods' names which would be ignored by check.
void	setMaxReturnCount(int maxReturnCount) Sets maximum allowed "return" literals count per method/ctor/lambda.
void	setMinIgnoreReturnDepth(int minIgnoreReturnDepth) Sets the minimum "return" statement depth with that will be skipped by check.
void	setTopLinesToIgnoreCount(int topLinesToIgnoreCount) Sets the count of code lines on the top of each processed method/ctor that will be ignored by check.
void	visitToken(com.puppycrawl.tools.checkstyle.api.DetailAST node)

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

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

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Detail

MSG_KEY_METHOD

public static final String MSG_KEY_METHOD

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

See Also:

Constant Field Values

MSG_KEY_CTOR

public static final String MSG_KEY_CTOR

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

See Also:

Constant Field Values

MSG_KEY_LAMBDA

public static final String MSG_KEY_LAMBDA

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

See Also:

Constant Field Values

Constructor Detail

ReturnCountExtendedCheck

public ReturnCountExtendedCheck()

Creates the new check instance.

Method Detail

setIgnoreMethodsNames

public void setIgnoreMethodsNames(String... ignoreMethodNames)

Sets the RegExp patterns for methods' names which would be ignored by check.

Parameters:

ignoreMethodNames - list of the RegExp patterns for methods' names which should be ignored by check

setMaxReturnCount

public void setMaxReturnCount(int maxReturnCount)

Sets maximum allowed "return" literals count per method/ctor/lambda.

Parameters:

maxReturnCount - - the new "maxReturnCount" property value.

See Also:

maxReturnCount

setIgnoreMethodLinesCount

public void setIgnoreMethodLinesCount(int ignoreMethodLinesCount)

Sets the maximum number of lines of which method/ctor/lambda body may consist to be skipped by check.

Parameters:

ignoreMethodLinesCount - - the new value of "ignoreMethodLinesCount" property.

See Also:

ignoreMethodLinesCount

setMinIgnoreReturnDepth

public void setMinIgnoreReturnDepth(int minIgnoreReturnDepth)

Sets the minimum "return" statement depth with that will be skipped by check.

Parameters:

minIgnoreReturnDepth - - the new "minIgnoreReturnDepth" property value.

setIgnoreEmptyReturns

public void setIgnoreEmptyReturns(boolean ignoreEmptyReturns)

Sets the "ignoring empty return statements in void methods and ctors and lambdas" option state.

Parameters:

ignoreEmptyReturns - the new "allowEmptyReturns" property value.

See Also:

ignoreEmptyReturns

setTopLinesToIgnoreCount

public void setTopLinesToIgnoreCount(int topLinesToIgnoreCount)

Sets the count of code lines on the top of each processed method/ctor that will be ignored by check.

Parameters:

topLinesToIgnoreCount - the new "rowsToIgnoreCount" property value.

See Also:

topLinesToIgnoreCount

getDefaultTokens

public int[] getDefaultTokens()

Specified by:

getDefaultTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

getAcceptableTokens

public int[] getAcceptableTokens()

Specified by:

getAcceptableTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

getRequiredTokens

public int[] getRequiredTokens()

Specified by:

getRequiredTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

visitToken

public void visitToken(com.puppycrawl.tools.checkstyle.api.DetailAST node)

Overrides:

visitToken in class com.puppycrawl.tools.checkstyle.api.AbstractCheck