fix: increase concurrency in tests to avoid OS performance differences

filter_test.go

@@ -38,18 +38,18 @@ func TestFilter(t *testing.T) {
 	t.Run("Concurrency yields reduced processing times", func(t *testing.T) {
 		pipeline := jpipe.New(context.TODO())
 		start := time.Now()
-		channel := jpipe.FromSlice(pipeline, []int{1, 2, 3, 4, 5}).
+		channel := jpipe.FromSlice(pipeline, []int{1, 2, 3, 4, 5, 6, 7, 8}).
 			Filter(func(i int) bool {
 				time.Sleep(10 * time.Millisecond)
 				return i%2 == 1
-			}, jpipe.Concurrent(3))
+			}, jpipe.Concurrent(4))
 
 		mappedValues := drainChannel(channel)
 		elapsed := time.Since(start)
 
 		slices.Sort(mappedValues) // The output order with concurrency is unpredictable
-		assert.Equal(t, []int{1, 3, 5}, mappedValues)
-		assert.Less(t, elapsed, 30*time.Millisecond) // It would have taken 50ms serially, but it takes about 20ms with 5 elements and concurrency 3
+		assert.Equal(t, []int{1, 3, 5, 7}, mappedValues)
+		assert.Less(t, elapsed, 40*time.Millisecond) // It would have taken 80ms serially, but it takes about 20ms with 8 elements and concurrency 4
 		assertPipelineDone(t, pipeline, 10*time.Millisecond)
 	})