feat: add billing and usage domain cores

backend/internal/usage/usage_test.go

@@ -0,0 +1,91 @@
+package usage
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"testing"
+	"time"
+)
+
+func TestUsageCoreFixtureIsConsumedByGo(t *testing.T) {
+	data, err := os.ReadFile("../../../contracts/usage/core-v1.json")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var fixture struct {
+		TimeZone  string `json:"timeZone"`
+		DedupeKey string `json:"dedupeKey"`
+		Excluded  struct {
+			Sources   []string `json:"sources"`
+			Providers []string `json:"providers"`
+		} `json:"excluded"`
+	}
+	if err := json.Unmarshal(data, &fixture); err != nil {
+		t.Fatal(err)
+	}
+	if fixture.TimeZone != "Asia/Shanghai" || fixture.DedupeKey != "jobId" || len(fixture.Excluded.Sources) != 1 || fixture.Excluded.Sources[0] != "api" || len(fixture.Excluded.Providers) != 1 || fixture.Excluded.Providers[0] != "mock" {
+		t.Fatalf("fixture = %#v", fixture)
+	}
+}
+
+func TestPresetUsesShanghaiCalendarBoundaries(t *testing.T) {
+	rangeValue, err := PresetRange(PresetMonth, time.Date(2026, 7, 27, 16, 30, 0, 0, time.UTC))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rangeValue.StartDate != "2026-07-01" || rangeValue.EndDate != "2026-07-28" || rangeValue.From != "2026-07-01T00:00:00+08:00" || rangeValue.To != "2026-07-29T00:00:00+08:00" || rangeValue.DayCount != 28 {
+		t.Fatalf("range = %#v", rangeValue)
+	}
+}
+
+func TestServiceDedupesEligibleEventsAndScopesReports(t *testing.T) {
+	repo := &memoryRepository{}
+	service := Service{Repository: repo}
+	for _, event := range []Event{
+		{ID: "1", JobID: "job-1", OwnerID: "a", Source: "platform", Provider: "bailian", OrganizationID: "org-1", AccountUsername: "secret", CreatedAt: "2026-07-03T01:00:00Z"},
+		{ID: "2", JobID: "job-1", OwnerID: "a", Source: "platform", Provider: "bailian", OrganizationID: "org-1", CreatedAt: "2026-07-03T01:01:00Z"},
+		{ID: "3", JobID: "job-api", OwnerID: "a", Source: "api", Provider: "bailian", OrganizationID: "org-1", CreatedAt: "2026-07-03T01:02:00Z"},
+		{ID: "4", JobID: "job-mock", OwnerID: "a", Source: "platform", Provider: "mock", OrganizationID: "org-1", CreatedAt: "2026-07-03T01:03:00Z"},
+		{ID: "5", JobID: "job-2", OwnerID: "b", Source: "platform", Provider: "seedance", OrganizationID: "org-2", AccountUsername: "other-secret", CreatedAt: "2026-07-03T01:04:00Z"},
+	} {
+		if _, err := service.Record(event); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	personal, err := service.Report(Requester{AccountID: "a", Role: "user"}, Filters{})
+	if err != nil || len(personal) != 1 || personal[0].OwnerID != "a" {
+		t.Fatalf("personal = %#v, %v", personal, err)
+	}
+	admin, err := service.Report(Requester{AccountID: "admin", OrganizationID: "org-1", Role: "organization_admin"}, Filters{})
+	if err != nil || len(admin) != 1 || admin[0].OrganizationID != "org-1" || admin[0].AccountUsername != "" {
+		t.Fatalf("admin = %#v, %v", admin, err)
+	}
+	super, err := service.Report(Requester{AccountID: "root", Role: "super_admin"}, Filters{})
+	if err != nil || len(super) != 2 || super[0].AccountUsername == "" {
+		t.Fatalf("super = %#v, %v", super, err)
+	}
+}
+
+func TestOrganizationAdminCannotEscapeOrganizationScope(t *testing.T) {
+	_, err := (Service{Repository: &memoryRepository{}}).Report(Requester{Role: "organization_admin", OrganizationID: "org-1"}, Filters{OrganizationID: "org-2"})
+	if !errors.Is(err, ErrForbidden) {
+		t.Fatalf("error = %v", err)
+	}
+}
+
+type memoryRepository struct{ events []Event }
+
+func (r *memoryRepository) Insert(event Event) (Event, bool, error) {
+	for _, current := range r.events {
+		if current.JobID == event.JobID {
+			return current, false, nil
+		}
+	}
+	r.events = append(r.events, event)
+	return event, true, nil
+}
+func (r *memoryRepository) List(filters Filters) ([]Event, error) {
+	return append([]Event(nil), r.events...), nil
+}