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

Class MissingSwitchDefaultCheck

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.MissingSwitchDefaultCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class MissingSwitchDefaultCheck extends AbstractCheck
Checks that switch statement has a default clause.

Rationale: It's usually a good idea to introduce a default case in every switch statement. Even if the developer is sure that all currently possible cases are covered, this should be expressed in the default branch, e.g. by using an assertion. This way the code is protected against later changes, e.g. introduction of new types in an enumeration type.

This check does not validate any switch expressions. Rationale: The compiler requires switch expressions to be exhaustive. This means that all possible inputs must be covered.

This check does not validate switch statements that use pattern or null labels. Rationale: Switch statements that use pattern or null labels are checked by the compiler for exhaustiveness. This means that all possible inputs must be covered.

See the Java Language Specification for more information about switch statements and expressions.

See the Java Language Specification for more information about patterns.

Since:
3.1

  • Field Details

  • Constructor Details

  • 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:

    • 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:

    • 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:

    • 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

    • containsDefaultLabel

      private static boolean containsDefaultLabel(DetailAST detailAst)
      Checks if the case group or its sibling contain the 'default' switch.
      Parameters:
      detailAst - first case group to check.
      Returns:
      true if 'default' switch found.

    • containsPatternCaseLabelElement

      private static boolean containsPatternCaseLabelElement(DetailAST detailAst)
      Checks if a switch block contains a case label with a pattern variable definition or record pattern definition. In this situation, the compiler enforces the given switch block to cover all possible inputs, and we do not need a default label.
      Parameters:
      detailAst - first case group to check.
      Returns:
      true if switch block contains a pattern case label element

    • containsDefaultCaseLabelElement

      private static boolean containsDefaultCaseLabelElement(DetailAST detailAst)
      Checks if a switch block contains a default case label.
      Parameters:
      detailAst - first case group to check.
      Returns:
      true if switch block contains default case label

    • containsNullCaseLabelElement

      private static boolean containsNullCaseLabelElement(DetailAST detailAst)
      Checks if a switch block contains a null case label.
      Parameters:
      detailAst - first case group to check.
      Returns:
      true if switch block contains null case label

    • isSwitchExpression

      private static boolean isSwitchExpression(DetailAST ast)
      Checks if this LITERAL_SWITCH token is part of a switch expression.
      Parameters:
      ast - the switch statement we are checking
      Returns:
      true if part of a switch expression

    • hasNullCaseLabel

      private static boolean hasNullCaseLabel(DetailAST detailAST)
      Checks if the case contains null label.
      Parameters:
      detailAST - the switch statement we are checking
      Returns:
      returnValue the ast of null label