[bugfix] Use case-insensitive selects when getting remote accounts by username/domain (#1191)

* [bugfix] Case-insensitive account selection

* don't lowercase cache key

internal/db/bundb/account.go

@@ -22,6 +22,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"codeberg.org/gruf/go-cache/v3/result"
@@ -108,11 +109,13 @@ func (a *accountDB) GetAccountByUsernameDomain(ctx context.Context, username str
 			q := a.newAccountQ(account)
 
 			if domain != "" {
-				q = q.Where("? = ?", bun.Ident("account.username"), username)
+				q = q.
-				q = q.Where("? = ?", bun.Ident("account.domain"), domain)
+					Where("LOWER(?) = ?", bun.Ident("account.username"), strings.ToLower(username)).
+					Where("? = ?", bun.Ident("account.domain"), domain)
 			} else {
-				q = q.Where("? = ?", bun.Ident("account.username"), username)
+				q = q.
-				q = q.Where("? IS NULL", bun.Ident("account.domain"))
+					Where("? = ?", bun.Ident("account.username"), strings.ToLower(username)). // usernames on our instance are always lowercase
+					Where("? IS NULL", bun.Ident("account.domain"))
 			}
 
 			return q.Scan(ctx)

internal/db/bundb/account_test.go

@@ -22,6 +22,7 @@ import (
 	"context"
 	"crypto/rand"
 	"crypto/rsa"
+	"strings"
 	"testing"
 	"time"
 
@@ -84,6 +85,22 @@ func (suite *AccountTestSuite) TestGetAccountByUsernameDomain() {
 	suite.NotNil(account2)
 }
 
+func (suite *AccountTestSuite) TestGetAccountByUsernameDomainMixedCase() {
+	testAccount := suite.testAccounts["remote_account_2"]
+
+	account1, err := suite.db.GetAccountByUsernameDomain(context.Background(), testAccount.Username, testAccount.Domain)
+	suite.NoError(err)
+	suite.NotNil(account1)
+
+	account2, err := suite.db.GetAccountByUsernameDomain(context.Background(), strings.ToUpper(testAccount.Username), testAccount.Domain)
+	suite.NoError(err)
+	suite.NotNil(account2)
+
+	account3, err := suite.db.GetAccountByUsernameDomain(context.Background(), strings.ToLower(testAccount.Username), testAccount.Domain)
+	suite.NoError(err)
+	suite.NotNil(account3)
+}
+
 func (suite *AccountTestSuite) TestUpdateAccount() {
 	ctx := context.Background()