Add unit tests for dashboard repository and enhance BSON handling

internal/dashboard/repository_test.go

@@ -0,0 +1,44 @@
+package dashboard
+
+import (
+	"testing"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+func TestFacetCountDecodesBSOND(t *testing.T) {
+	facet := bson.M{
+		"total": bson.A{
+			bson.D{{Key: "count", Value: int32(42)}},
+		},
+		"active": bson.A{
+			bson.D{{Key: "count", Value: int64(7)}},
+		},
+	}
+
+	if got := facetCount(facet, "total"); got != 42 {
+		t.Fatalf("expected total 42, got %d", got)
+	}
+	if got := facetCount(facet, "active"); got != 7 {
+		t.Fatalf("expected active 7, got %d", got)
+	}
+}
+
+func TestFacetCurrencyValueDecodesBSOND(t *testing.T) {
+	facet := bson.M{
+		"currency_value": bson.A{
+			bson.D{
+				{Key: "_id", Value: "eur"},
+				{Key: "total", Value: float64(12345.67)},
+			},
+		},
+	}
+
+	currency, total := facetCurrencyValue(facet)
+	if currency != "EUR" {
+		t.Fatalf("expected EUR, got %q", currency)
+	}
+	if total != 12345.67 {
+		t.Fatalf("expected 12345.67, got %f", total)
+	}
+}