Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/service/credential_shadow_test.go

@@ -0,0 +1,46 @@
+package service
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// stubCredRepo 是最小化 AccountRepository stub，仅实现 GetByID，供 credential_shadow_test 使用。
+// 嵌入接口满足完整方法集；未实现的方法若被调用会 panic，从而快速暴露误调用。
+type stubCredRepo struct {
+	AccountRepository
+	parent *Account
+}
+
+func (s *stubCredRepo) GetByID(_ context.Context, _ int64) (*Account, error) {
+	return s.parent, nil
+}
+
+func newStubCredRepo(parent *Account) AccountRepository {
+	return &stubCredRepo{parent: parent}
+}
+
+func TestResolveCredentialAccount(t *testing.T) {
+	ctx := context.Background()
+	pid := int64(100)
+
+	// 普通账号（非影子）→ 返回自身
+	parent := &Account{ID: 100, Platform: PlatformOpenAI, Type: AccountTypeOAuth, Status: StatusActive}
+	repo := newStubCredRepo(parent)
+	got, err := resolveCredentialAccount(ctx, repo, parent)
+	require.NoError(t, err)
+	require.Equal(t, int64(100), got.ID)
+
+	// 影子账号 + 合法 OpenAI OAuth 母账号 → 返回母账号
+	shadow := &Account{ID: 200, ParentAccountID: &pid, Platform: PlatformOpenAI, Type: AccountTypeOAuth}
+	got, err = resolveCredentialAccount(ctx, repo, shadow)
+	require.NoError(t, err)
+	require.Equal(t, int64(100), got.ID)
+
+	// 影子账号 + 母账号非 OpenAI OAuth（API Key 类型）→ 返回 error
+	badRepo := newStubCredRepo(&Account{ID: 100, Platform: PlatformOpenAI, Type: AccountTypeAPIKey})
+	_, err = resolveCredentialAccount(ctx, badRepo, shadow)
+	require.Error(t, err)
+}