Spotless: Keep your code spotless

You probably want one of the links below:

❇️ Spotless for Gradle (with integrations for VS Code and IntelliJ)

user@machine repo % ./gradlew build
:spotlessJavaCheck FAILED
  The following files had format violations:
  src\main\java\com\diffplug\gradle\spotless\FormatExtension.java
    -\t\t····if·(targets.length·==·0)·{
    +\t\tif·(targets.length·==·0)·{
  Run './gradlew spotlessApply' to fix these violations.
user@machine repo % ./gradlew spotlessApply
:spotlessApply
BUILD SUCCESSFUL
user@machine repo % ./gradlew build
BUILD SUCCESSFUL

❇️ Spotless for Maven

user@machine repo % mvn spotless:check
[ERROR]  > The following files had format violations:
[ERROR]  src\main\java\com\diffplug\gradle\spotless\FormatExtension.java
[ERROR]    -\t\t····if·(targets.length·==·0)·{
[ERROR]    +\t\tif·(targets.length·==·0)·{
[ERROR]  Run 'mvn spotless:apply' to fix these violations.
user@machine repo % mvn spotless:apply
[INFO] BUILD SUCCESS
user@machine repo % mvn spotless:check
[INFO] BUILD SUCCESS

❇️ Spotless for SBT (external for now)

Other build systems

How it works (for potential contributors)

Ideally, a code formatter can do more than just find formatting errors - it should fix them as well. Such a formatter is just a Function<String, String>, which returns a formatted version of its potentially unformatted input.

It's easy to build such a function, but there are some gotchas and lots of integration work (newlines, character encodings, idempotency, git ratcheting, and build-system integration). Spotless tackles those for you so you can focus on just a simple Function<String, String> which can compose with any of the other formatters and build tools in Spotless' arsenal.

Current feature matrix

Feature / FormatterStep	gradle	maven	sbt	(Your build tool here)
Automatic idempotency safeguard	:+1:	:+1:	:+1:	:white_large_square:
Misconfigured encoding safeguard	:+1:	:+1:	:+1:	:white_large_square:
Toggle with `spotless:off` and `spotless:on`	:+1:	:+1:	:white_large_square:	:white_large_square:
Ratchet from `origin/main` or other git ref	:+1:	:+1:	:white_large_square:	:white_large_square:
Define line endings using git	:+1:	:+1:	:+1:	:white_large_square:
Fast incremental format and up-to-date check	:+1:	:+1:	:white_large_square:	:white_large_square:
Fast format on fresh checkout using buildcache	:+1:	:white_large_square:	:white_large_square:	:white_large_square:
`generic.EndWithNewlineStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`generic.IndentStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`generic.Jsr223Step`	:white_large_square:	:+1:	:white_large_square:	:white_large_square:
`generic.LicenseHeaderStep`	:+1:	:+1:	:+1:	:white_large_square:
`generic.NativeCmdStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`generic.ReplaceRegexStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`generic.ReplaceStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`generic.TrimTrailingWhitespaceStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`antlr4.Antlr4FormatterStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`biome.BiomeStep`	:+1:	:+1:	:white_large_square:	:white_large_square:
`cpp.ClangFormatStep`	:+1:	:white_large_square:	:white_large_square:	:white_large_square:
`cpp.EclipseFormatterStep`	:+1:	:+1:	:+1:	:white_large_square: