Package com.puppycrawl.tools.checkstyle.checks.coding

Class ParameterAssignmentCheck

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.ParameterAssignmentCheck

All Implemented Interfaces:

Configurable, Contextualizable

public final class ParameterAssignmentCheck
extends AbstractCheck

Disallows assignment of parameters.

Rationale: Parameter assignment is often considered poor programming practice. Forcing developers to declare parameters as final is often onerous. Having a check ensure that parameters are never assigned would give the best of both worlds.

Since:

3.2

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.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.
private Set<String>	parameterNames	Current set of parameters.
private final Deque<Set<String>>	parameterNamesStack	Stack of methods' parameters.

Constructor Summary

Constructors

Constructor	Description
ParameterAssignmentCheck()

Method Summary

Modifier and Type	Method	Description
void	beginTree(DetailAST rootAST)	Called before the starting to process a tree.
private void	checkNestedIdent(DetailAST ast)	Check if nested ident is parameter.
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.
void	leaveToken(DetailAST ast)	Called after all the child nodes have been process.
private void	visitLambda(DetailAST lambdaAst)	Creates new set of parameters and store old one in stack.
private void	visitLambdaParameters(DetailAST ast)	Creates new parameter set for given lambda expression.
private void	visitMethodDef(DetailAST ast)	Creates new set of parameters and store old one in stack.
private void	visitMethodParameters(DetailAST ast)	Creates new parameter set for given method.
private void	visitParameters(DetailAST parametersAst)	Visits parameter list and adds parameter names to the set.
void	visitToken(DetailAST ast)	Called to process a token.

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

clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, 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.AbstractAutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.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

parameterNamesStack

private final Deque<Set<String>> parameterNamesStack

Stack of methods' parameters.

parameterNames

private Set<String> parameterNames

Current set of parameters.

Constructor Details

ParameterAssignmentCheck

public ParameterAssignmentCheck()

Method Details

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

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

beginTree

public void beginTree(DetailAST rootAST)

Description copied from class: AbstractCheck

Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.

Overrides:

beginTree in class AbstractCheck

Parameters:

rootAST - the root of the tree

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

leaveToken

public void leaveToken(DetailAST ast)

Description copied from class: AbstractCheck

Called after all the child nodes have been process.

Overrides:

leaveToken in class AbstractCheck

Parameters:

ast - the token leaving

checkNestedIdent

private void checkNestedIdent(DetailAST ast)

Check if nested ident is parameter.

Parameters:

ast - parent of node of ident

visitMethodDef

private void visitMethodDef(DetailAST ast)

Creates new set of parameters and store old one in stack.

Parameters:

ast - a method to process.

visitLambda

private void visitLambda(DetailAST lambdaAst)

Creates new set of parameters and store old one in stack.

Parameters:

lambdaAst - node of type TokenTypes.LAMBDA.

visitMethodParameters

private void visitMethodParameters(DetailAST ast)

Creates new parameter set for given method.

Parameters:

ast - a method for process.

visitLambdaParameters

private void visitLambdaParameters(DetailAST ast)

Creates new parameter set for given lambda expression.

Parameters:

ast - a lambda expression parameter to process

visitParameters

private void visitParameters(DetailAST parametersAst)

Visits parameter list and adds parameter names to the set.

Parameters:

parametersAst - ast node of type TokenTypes.PARAMETERS.