task 305: add ring time series with wrap-around and gap tests

1 files changed, 65 insertions, 0 deletions

diff --git a/internal/statsengine/timeseries_test.go b/internal/statsengine/timeseries_test.go
new file mode 100644
index 0000000..bb11157
--- /dev/null
+++ b/internal/statsengine/timeseries_test.go
@@ -0,0 +1,65 @@
+package statsengine
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func TestRingTimeSeriesAveragesWithinSlot(t *testing.T) {
+	r := newRingTimeSeriesWithConfig(time.Second, 4)
+	base := time.Unix(0, 0)
+
+	r.Add(10, base)
+	r.Add(20, base.Add(400*time.Millisecond))
+
+	got := r.Values()
+	want := []float64{0, 0, 0, 15}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("unexpected values: got %v want %v", got, want)
+	}
+}
+
+func TestRingTimeSeriesWrapAround(t *testing.T) {
+	r := newRingTimeSeriesWithConfig(time.Second, 4)
+	base := time.Unix(0, 0)
+
+	for i := 0; i < 6; i++ {
+		r.Add(float64(i+1), base.Add(time.Duration(i)*time.Second))
+	}
+
+	got := r.Values()
+	want := []float64{3, 4, 5, 6}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("unexpected wrap-around values: got %v want %v", got, want)
+	}
+}
+
+func TestRingTimeSeriesGapHandling(t *testing.T) {
+	r := newRingTimeSeriesWithConfig(time.Second, 4)
+	base := time.Unix(0, 0)
+
+	r.Add(10, base)
+	r.Add(40, base.Add(3*time.Second))
+
+	got := r.Values()
+	want := []float64{10, 0, 0, 40}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("unexpected gap values: got %v want %v", got, want)
+	}
+}
+
+func TestRingTimeSeriesIgnoresTooOldSamples(t *testing.T) {
+	r := newRingTimeSeriesWithConfig(time.Second, 4)
+	base := time.Unix(0, 0)
+
+	r.Add(1, base)
+	r.Add(5, base.Add(5*time.Second))
+	r.Add(99, base)
+
+	got := r.Values()
+	want := []float64{0, 0, 0, 5}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("unexpected values with old sample: got %v want %v", got, want)
+	}
+}