v2.42.0: Error Prone 2.42.0

New checks:

• ExplicitArrayForVarargs: discourage unnecessary explicit construction of an array to provide varargs.
• FloggerPerWithoutRateLimit: discourage Flogger's perUnique without rate limiting
• StringJoin: Ban String.join(CharSequence) and String.join(CharSequence, CharSequence)
• ThreadBuilderNameWithPlaceholder: Do not allow placeholders in Thread.Builder.name(String) or name(String, int).

Changes:

• The return type of ASTHelpers.asFlagSet has changed. The previous type was EnumSet<Flags.Flag>, where Flags.Flag is an enum in the javac class Flags. A recent JDK change has replaced that enum with a new top-level enum called FlagsEnum. It is not possible to change ASTHelpers.asFlagSet in a way that would be type-safe and compatible with the enums from JDKs both before and after the change. Instead, the method now returns ImmutableSet<String>, where the strings come from the toString() of the enum constants. That means they are "native", "abstract", etc.
• Flag IO.print[ln]() in SystemOut.

Full changelog: google/error-prone@v2.41.0...v2.42.0

v2.41.0: Error Prone 2.41.0

New checks:

• EffectivelyPrivate: Detect declarations that have public or protected modifiers, but are effectively private

Changes:

• Skip BooleanLiteral findings if the target type is boxed (#​5134)

Full changelog: google/error-prone@v2.40.0...v2.41.0

v2.40.0: Error Prone 2.40.0

Changes:

• Bug fixes and improvements
• Releases (including snapshots) have migrated from OSSRH to the Central Publisher Portal

Full changelog: google/error-prone@v2.39.0...v2.40.0

v2.39.0: Error Prone 2.39.0

Changes:

• Temporarily downgrade to Guava 33.4.0 (#​5108)

Checks:

• BooleanLiteral: Prefer true to Boolean.TRUE
• ExpensiveLenientFormatString: Renamed from PreconditionsExpensiveString, detects unnecessary calls to String.format in the arguments of lenient formatting methods.
• UnnecessaryQualifier: Detects @Qualifier or @BindingAnnotation annotations that have no effect, and can be removed

Issues: #​4996, #​5045

Full changelog: google/error-prone@v2.38.0...v2.39.0