fix: income at correct position in recommended envelopes (#899)

Author: morremeyer

pkg/models/account.go

@@ -183,7 +183,7 @@ func (a Account) RecentEnvelopes(db *gorm.DB) ([]*uuid.UUID, error) {
 	latest := db.
 		Model(&Transaction{}).
 		Joins("LEFT JOIN envelopes ON envelopes.id = transactions.envelope_id AND envelopes.deleted_at IS NULL").
-		Select("envelopes.id as id, datetime(envelopes.created_at) as created").
+		Select("envelopes.id as e_id, datetime(envelopes.created_at) as created").
 		Where(&Transaction{
 			TransactionCreate: TransactionCreate{
 				DestinationAccountID: a.ID,
@@ -195,7 +195,8 @@ func (a Account) RecentEnvelopes(db *gorm.DB) ([]*uuid.UUID, error) {
 	// Group by frequency
 	err := db.
 		Table("(?)", latest).
-		Select("id").
+		// Set the nil UUID as ID if the envelope ID is NULL, since count() only counts non-null values
+		Select("IIF(e_id IS NOT NULL, e_id, '00000000-0000-0000-0000-000000000000') as id").
 		Group("id").
 		Order("count(id) DESC").
 		Order("created ASC").

pkg/models/account_test.go

@@ -308,7 +308,7 @@ func (suite *TestSuiteStandard) TestAccountRecentEnvelopes() {
 		// Sleep for 10 milliseconds because we only save timestamps with 1 millisecond accuracy
 		// This is needed because the test runs so fast that all envelopes are sometimes created
 		// within the same millisecond, making the result non-deterministic
-		time.Sleep(1 * time.Second)
+		time.Sleep(1 * time.Millisecond)
 	}
 
 	// Create 15 transactions:
@@ -329,14 +329,24 @@ func (suite *TestSuiteStandard) TestAccountRecentEnvelopes() {
 		})
 	}
 
-	// Create one income transaction
-	_ = suite.createTestTransaction(models.TransactionCreate{
-		BudgetID:             budget.ID,
-		EnvelopeID:           nil,
-		SourceAccountID:      externalAccount.ID,
-		DestinationAccountID: account.ID,
-		Amount:               decimal.NewFromFloat(1337.42),
-	})
+	// Create three income transactions
+	//
+	// This is a regression test for income always showing at the last
+	// position in the recent envelopes (before the LIMIT) since count(id) for
+	// income was always 0. This is due to the envelope ID for income being NULL
+	// and count() not counting NULL values.
+	//
+	// Creating three income transactions puts "income" as the second most common
+	// envelope, verifying the fix
+	for i := 0; i < 3; i++ {
+		_ = suite.createTestTransaction(models.TransactionCreate{
+			BudgetID:             budget.ID,
+			EnvelopeID:           nil,
+			SourceAccountID:      externalAccount.ID,
+			DestinationAccountID: account.ID,
+			Amount:               decimal.NewFromFloat(1337.42),
+		})
+	}
 
 	ids, err := account.RecentEnvelopes(suite.db)
 	if err != nil {
@@ -351,9 +361,9 @@ func (suite *TestSuiteStandard) TestAccountRecentEnvelopes() {
 	// has been the most common one
 	suite.Assert().Equal(envelopeIDs[2], ids[0])
 
-	// Order for envelopes with the same frequency is undefined
-
-	// Income is the last one since it only appears once
+	// Income is the second one since it appears three times
 	var nilUUIDPointer *uuid.UUID
-	suite.Assert().Equal(nilUUIDPointer, ids[3])
+	suite.Assert().Equal(nilUUIDPointer, ids[1])
+
+	// Order for envelopes with the same frequency is undefined
 }