Fix Expand bug

pkg/kubecost/asset.go

@@ -42,10 +42,10 @@ type Asset interface {
 	// Temporal values
 	Start() time.Time
 	End() time.Time
-	Minutes() float64
+	SetStartEnd(time.Time, time.Time)
 	Window() Window
 	ExpandWindow(Window)
-	SetStartEnd(time.Time, time.Time)
+	Minutes() float64
 
 	// Operations and comparisons
 	Add(Asset) Asset
@@ -2697,15 +2697,17 @@ func (as *AssetSet) Get(key string) (Asset, bool) {
 // configured properties to determine the key under which the Asset will
 // be inserted.
 func (as *AssetSet) Insert(asset Asset) error {
-	if as.IsEmpty() {
-		as.Lock()
-		as.assets = map[string]Asset{}
-		as.Unlock()
+	if as == nil {
+		return fmt.Errorf("cannot Insert into nil AssetSet")
 	}
 
 	as.Lock()
 	defer as.Unlock()
 
+	if as.assets == nil {
+		as.assets = map[string]Asset{}
+	}
+
 	// Determine key into which to Insert the Asset.
 	k, err := key(asset, as.aggregateBy)
 	if err != nil {
@@ -2828,9 +2830,11 @@ func (as *AssetSet) accumulate(that *AssetSet) (*AssetSet, error) {
 	// Set start, end to min(start), max(end)
 	start := as.Start()
 	end := as.End()
+
 	if that.Start().Before(start) {
 		start = that.Start()
 	}
+
 	if that.End().After(end) {
 		end = that.End()
 	}

pkg/kubecost/asset_test.go

@@ -153,7 +153,7 @@ func assertAssetSet(t *testing.T, as *AssetSet, msg string, window Window, exps
 				t.Fatalf("AssetSet.AggregateBy[%s]: key %s expected total cost %.2f, actual %.2f", msg, key, exp, a.TotalCost())
 			}
 			if !a.Window().Equal(window) {
-				t.Fatalf("AssetSet.AggregateBy[%s]: key %s expected window %s, actual %s", msg, key, window, as.Window)
+				t.Fatalf("AssetSet.AggregateBy[%s]: key %s expected window %s, actual %s", msg, key, window, a.Window())
 			}
 		} else {
 			t.Fatalf("AssetSet.AggregateBy[%s]: unexpected asset: %s", msg, key)
@@ -837,7 +837,6 @@ func TestAssetSet_AggregateBy(t *testing.T) {
 	if err != nil {
 		t.Fatalf("AssetSet.AggregateBy: unexpected error: %s", err)
 	}
-	fmt.Println(as.assets)
 	assertAssetSet(t, as, "1e", window, map[string]float64{
 		"__undefined__": 53.00,
 		"test=test":     7.00,
@@ -1011,6 +1010,7 @@ func TestAssetSetRange_Accumulate(t *testing.T) {
 		generateAssetSet(startD1),
 		generateAssetSet(startD2),
 	)
+
 	err = asr.AggregateBy([]string{string(AssetTypeProp)}, nil)
 	as, err = asr.Accumulate()
 	if err != nil {

pkg/kubecost/window.go

@@ -393,21 +393,19 @@ func (w Window) ExpandEnd(end time.Time) Window {
 }
 
 func (w Window) Expand(that Window) Window {
-	result := w
-
 	if that.start == nil {
-		result.start = nil
+		w.start = nil
 	} else {
-		result = w.ExpandStart(*that.start)
+		w = w.ExpandStart(*that.start)
 	}
 
 	if that.end == nil {
-		result.end = nil
+		w.end = nil
 	} else {
-		result = w.ExpandEnd(*that.end)
+		w = w.ExpandEnd(*that.end)
 	}
 
-	return result
+	return w
 }
 
 func (w Window) Hours() float64 {