resilient-test/com.santimattius.resilient.test/FaultInjector

FaultInjector

class FaultInjector(failureRate: Double = 0.0, exception: () -> Throwable = { FaultInjectedException() }, delay: Duration = Duration.ZERO, delayJitter: Boolean = false, failCount: Int = 0)

Fault injection helper for testing resilience policies.

Use this in tests to inject artificial delays, failures, or intermittent behavior to validate that your policies (retry, circuit breaker, timeout, etc.) handle them correctly.

Prefer failCount over failureRate for deterministic tests — failureRate introduces randomness that can cause intermittent test failures.

Example — deterministic (preferred):

val injector = FaultInjector.builder()
    .failCount(3) // fails first 3 calls, succeeds after
    .build()

Example — probabilistic:

val injector = FaultInjector.builder()
    .failureRate(0.3)
    .delay(50.milliseconds)
    .build()

Constructors

FaultInjector

constructor(failureRate: Double = 0.0, exception: () -> Throwable = { FaultInjectedException() }, delay: Duration = Duration.ZERO, delayJitter: Boolean = false, failCount: Int = 0)

Types

Builder

class Builder

Builder for FaultInjector.

Companion

object Companion

Functions

execute

suspend fun <T> execute(block: suspend () -> T): T

Executes block, potentially injecting a delay and/or failure according to configuration.