FailureDetails.IsCausedBy throws

When an activity function throws an exception, and it is caught by a custom retry handler in an orchestrator, the retryContext allows accessing the FailureDetails for analysis of the failure. However, attempting to use the FailureDetails.isCausedBy() method will never succeed, as it internally is implemented using Class.forName() which requires the fully-qualified exception class name but FailureDetails does not have this information serialized, just the simple exception class name.

Repro:

    @FunctionName("CustomRetryActivityFunction")
    public String customRetryActivityFunction(
            @DurableOrchestrationTrigger(name = "ctx") TaskOrchestrationContext ctx) {
        TaskOptions options = new TaskOptions(retryContext -> {
            FailureDetails lastFailure = retryContext.getLastFailure();
            if (lastFailure != null
                    && lastFailure.getErrorType().equals("OverflowException")
                    // This line should work, but doesn't
                    // && lastFailure.isCausedBy(InvalidOperationException.class)
                    && retryContext.getLastAttemptNumber() < 3) {
                return true;
            }
            return false;
        });
        return ctx.callActivity("RaiseComplexException", ctx.getInstanceId(), options, String.class).await();
    }
``

Comienza en FailureDetails.isCausedBy() y sigue cómo se serializa y reconstruye el tipo de error del fallo al acceder a él mediante retryContext. Usa el controlador de reintentos personalizado proporcionado y el escenario de excepción para reproducir el fallo. Se considera terminado cuando isCausedBy() puede evaluar correctamente la clase de la causa, con cobertura para el caso reproducido.