fix: poll w/ solely until predicate

src/Arcus.Testing.Core/Poll.cs

@@ -111,7 +111,7 @@ public async Task<TResult> StartAsync()
                 Policy.HandleResult((TResult r) =>
                       {
                           results.Add(r);
-                          return _untilTargets.Count > 0 && _untilTargets.Any(untilTarget => untilTarget(r));
+                          return !_untilTargets.All(untilTarget => untilTarget(r));
                       }).Or<TException>(ex =>
                       {
                           exceptions.Add(ex);

src/Arcus.Testing.Tests.Unit/Core/PollTests.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.IO;
 using System.Threading.Tasks;
 using Bogus;
@@ -63,6 +64,26 @@ public async Task Poll_WithDiffExceptionThanUnavailableTarget_FailsDirectlyWithD
             await FailsByExceptionAsync(async () => await Poll.Target<object, ApplicationException>(AlwaysFailsResultAsync).MinTimeFrame());
         }
 
+        [Fact]
+        public async Task Poll_WithUntilPredicate_SucceedsAfterThirdTime()
+        {
+            // Arrange
+            var stopwatch = Stopwatch.StartNew();
+
+            int index = 0;
+            TimeSpan timeout = TimeSpan.FromSeconds(1);
+            TimeSpan interval = TimeSpan.FromMilliseconds(200);
+
+            // Act
+            await Poll.Target(() => Task.FromResult(++index))
+                      .Until(result => result >= 3)
+                      .Every(interval)
+                      .Timeout(timeout);
+
+            // Assert
+            Assert.True(interval + interval <= stopwatch.Elapsed, "stopwatch should at least run until two intervals");
+        }
+
         [Fact]
         public async Task Poll_WithNegativeUntilTargetPredicate_FailsWithDescription()
         {