From b9ff4d48b2a9c21b19bb2484cb82d5082621696e Mon Sep 17 00:00:00 2001
From: Adam Warski <adam@warski.org>
Date: Fri, 29 May 2026 19:05:13 +0000
Subject: [PATCH] Add failing test: Fix AdaptiveRetry stopping on Left when
 shouldPayFailureCost is false

---
 .../ox/resilience/AdaptiveRetryTest.scala     | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 core/src/test/scala/ox/resilience/AdaptiveRetryTest.scala

diff --git a/core/src/test/scala/ox/resilience/AdaptiveRetryTest.scala b/core/src/test/scala/ox/resilience/AdaptiveRetryTest.scala
new file mode 100644
index 00000000..8ef7a490
--- /dev/null
+++ b/core/src/test/scala/ox/resilience/AdaptiveRetryTest.scala
@@ -0,0 +1,32 @@
+package ox.resilience
+
+import org.scalatest.EitherValues
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+import ox.scheduling.Schedule
+
+class AdaptiveRetryTest extends AnyFlatSpec with EitherValues with Matchers:
+
+  behavior of "AdaptiveRetry"
+
+  it should "not pay failureCost if result E is going to be retried and shouldPayFailureCost returns false" in:
+    // given
+    var counter = 0
+    val errorMessage = "boom"
+
+    def f: Either[String, Int] =
+      counter += 1
+      Left(errorMessage)
+
+    // Bucket smaller than the number of attempts: if the cost were paid, we'd stop early.
+    val adaptive = AdaptiveRetry(TokenBucket(2), 1, 1)
+
+    // when
+    val result = adaptive.retryEither(Schedule.immediate.maxRetries(5), _ => false)(f)
+
+    // then
+    result.left.value shouldBe errorMessage
+    // 1 initial + 5 retries, all for free since shouldPayFailureCost returns false
+    counter shouldBe 6
+
+end AdaptiveRetryTest