All Implemented Interfaces and Traits:

ASTTransformation, CompilationUnitAware

public class LoopInvariantASTTransformation
extends Object
implements ASTTransformation, CompilationUnitAware

Handles Invariant annotations placed on loop statements (for, while, do-while). For for and while loops the invariant closure is evaluated as an assertion at the start of each loop iteration. For do-while loops it is evaluated after each body execution instead (GROOVY-12128): the body runs before the first condition check, so the invariant only needs to be established by that first execution — checking it at loop entry would reject valid loops. (A continue inside a do-while jumps straight to the condition and therefore skips the check for that pass.)

When @Invariant is placed on a class (its original usage), this transform returns immediately, letting the existing global contract pipeline handle it.

Example:

 int sum = 0
 @Invariant({ 0 <= i && i <= 4 })
 for (int i in 0..4) {
     sum += i
 }
 

Since:

6.0.0

See Also:

Invariant

LoopInvariantViolation