Add failing test: Fix AdaptiveRetry stopping retries on retriable Left when shouldPayFailureCost is false

Author: adamw

core/src/test/scala/ox/resilience/ImmediateRetryTest.scala

@@ -210,4 +210,22 @@ class ImmediateRetryTest extends AnyFlatSpec with EitherValues with TryValues wi
     result.value shouldBe message
     counter shouldBe 6
 
+  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 =
+      counter += 1
+      Left(errorMessage)
+
+    val adaptive = AdaptiveRetry(TokenBucket(2), 1, 1)
+    // when
+    val result = adaptive.retryEither(Schedule.immediate.maxRetries(5), _ => false)(f)
+
+    // then
+    result.left.value shouldBe errorMessage
+    // all attempts are made for free, without paying the failure cost: one initial + five retries
+    counter shouldBe 6
+
 end ImmediateRetryTest