Package com.puppycrawl.tools.checkstyle.checks.naming

Class GoogleMethodNameCheck

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.naming.GoogleMethodNameCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class GoogleMethodNameCheck extends AbstractCheck
Checks that method names conform to the Google Java Style Guide for method naming.

This check enforces Google's specific method naming requirements:

  • Method names must start with a lowercase letter and use uppercase letters for word boundaries.
  • Underscores may appear in JUnit test method names to separate logical components.
  • Underscores may be used to separate adjacent numbers (e.g., version numbers like guava33_4_5), but NOT between letters and digits.
Since:
13.1.0

  • Field Details

    • MSG_KEY_FORMAT_REGULAR

      public static final String MSG_KEY_FORMAT_REGULAR
      A key is pointing to the violation message text in "messages.properties" file.
      See Also:

    • MSG_KEY_FORMAT_TEST

      public static final String MSG_KEY_FORMAT_TEST
      A key is pointing to the violation message text in "messages.properties" file.
      See Also:

    • MSG_KEY_UNDERSCORE_REGULAR

      public static final String MSG_KEY_UNDERSCORE_REGULAR
      A key is pointing to the violation message text in "messages.properties" file.
      See Also:

    • MSG_KEY_UNDERSCORE_TEST

      public static final String MSG_KEY_UNDERSCORE_TEST
      A key is pointing to the violation message text in "messages.properties" file.
      See Also:

    • REGULAR_METHOD_NAME_PATTERN

      private static final Pattern REGULAR_METHOD_NAME_PATTERN
      Pattern for valid regular method names in Google style. Format: start with lowercase, have at least 2 chars, optionally followed by numbering suffix.

      Explanation:

      • ^(?![a-z]$) - Negative lookahead: cannot be single lowercase char
      • (?![a-z][A-Z]) - Negative lookahead: cannot be like "fO"
      • [a-z] - Must start with lowercase
      • [a-z0-9]*+ - Followed by lowercase or digits
      • (?:[A-Z][a-z0-9]*+)*+ - CamelCase humps (uppercase followed by lowercase/digits)
      • $ - End of string (numbering suffix validated separately)

    • TEST_METHOD_NAME_PATTERN

      private static final Pattern TEST_METHOD_NAME_PATTERN
      Pattern for valid test method names in Google style. Each segment between underscores must:
      • Start with lowercase
      • Be at least 2 characters long
      • Not start with single lowercase followed by uppercase (e.g., "fO")

    • NUMBERING_SUFFIX_PATTERN

      private static final Pattern NUMBERING_SUFFIX_PATTERN
      Pattern to strip trailing numbering suffix (underscore followed by digits).

    • INVALID_UNDERSCORE_PATTERN_REGULAR

      private static final Pattern INVALID_UNDERSCORE_PATTERN_REGULAR
      Matches invalid underscore usage for regular methods: leading, trailing, double, or between any characters (letter-letter, letter-digit, digit-letter).

    • INVALID_UNDERSCORE_PATTERN_TEST

      private static final Pattern INVALID_UNDERSCORE_PATTERN_TEST
      Matches invalid underscore usage for test methods: leading, trailing, double, or between letter-digit/digit-letter.

    • TEST_ANNOTATIONS

      private static final Set<String> TEST_ANNOTATIONS
      Set of JUnit 5 test annotation names that indicate a test method.

  • 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

    • hasTestAnnotation

      private static boolean hasTestAnnotation(DetailAST methodDef)
      Checks if the method has any test annotation.
      Parameters:
      methodDef - the METHOD_DEF AST node
      Returns:
      true if the method has @Test, @ParameterizedTest, or @RepeatedTest annotation.

    • validateRegularMethodName

      private void validateRegularMethodName(DetailAST nameAst, String methodName)
      Validates a regular (non-test) method name according to Google style.
      Parameters:
      nameAst - the IDENT AST node containing the method name
      methodName - the method name string

    • validateTestMethodName

      private void validateTestMethodName(DetailAST nameAst, String methodName)
      Validates a test method name according to Google style.
      Parameters:
      nameAst - the IDENT AST node containing the method name
      methodName - the method name string