fix(tests): fix db mock for legacy referral bonus calculation

Author: brandonkachen

packages/billing/src/__tests__/grant-credits.test.ts

@@ -447,15 +447,17 @@ describe('grant-credits', () => {
         }
         const legacyReferralBonus = 500
 
+        // Mock db for calculateTotalLegacyReferralBonus (uses db directly, not tx)
+        // This mock needs to return the referral query result for the legacy bonus calculation
         await mockModule('@codebuff/internal/db', () => ({
           default: {
             select: () => ({
               from: () => ({
-                where: () => ({
-                  orderBy: () => ({
-                    limit: () => [],
-                  }),
-                }),
+                where: () => {
+                  // Return referral bonus for calculateTotalLegacyReferralBonus
+                  // This is a thenable that returns the referral bonus result
+                  return Promise.resolve([{ totalCredits: String(legacyReferralBonus) }])
+                },
               }),
             }),
           },
@@ -491,15 +493,15 @@ describe('grant-credits', () => {
         }
         const legacyReferralBonus = 0 // No legacy referrals
 
+        // Mock db for calculateTotalLegacyReferralBonus (uses db directly, not tx)
         await mockModule('@codebuff/internal/db', () => ({
           default: {
             select: () => ({
               from: () => ({
-                where: () => ({
-                  orderBy: () => ({
-                    limit: () => [],
-                  }),
-                }),
+                where: () => {
+                  // Return 0 referral bonus for calculateTotalLegacyReferralBonus
+                  return Promise.resolve([{ totalCredits: String(legacyReferralBonus) }])
+                },
               }),
             }),
           },