@Incubating
class PurityChecker
extends TypeCheckingDSL

A compile-time checker that verifies @Pure methods have no side effects.

By default, strict purity is enforced: no field mutations, no I/O, no logging, no non-deterministic calls. The allows option declares which effect categories are tolerated:

 // Strict: no side effects at all
 @TypeChecked(extensions = 'groovy.typecheckers.PurityChecker')

 // Tolerate logging and metrics
 @TypeChecked(extensions = 'groovy.typecheckers.PurityChecker(allows: "LOGGING|METRICS")')
 

Effect categories:

• LOGGING — calls to logging frameworks (SLF4J, JUL, etc.) and println
• METRICS — calls to metrics instruments (Micrometer, OpenTelemetry, etc.)
• IO — file, network, database, and console I/O
• NONDETERMINISM — time-dependent, random, and environment-dependent calls

Also recognises:

• @SideEffectFree (Checker Framework) — treated as @Pure with implicit NONDETERMINISM allowed
• @Contract(pure = true) (JetBrains) — treated as @Pure
• @Memoized — treated as effectively pure

Since:

6.0.0

See Also:

Pure