[bugfix] Better Postgres search case insensitivity (#2526)

* [bugfix] Better Postgres search case insensitivity

* use ilike for postgres

internal/db/bundb/search.go

@@ -133,8 +133,7 @@ func (s *searchDB) SearchForAccounts(
 		// Normalize it and just look for
 		// usernames that start with query.
 		query = query[1:]
-		subQ := s.accountUsername()
-		q = whereStartsLike(q, subQ, query)
+		q = whereStartsLike(q, bun.Ident("account.username"), query)
 	} else {
 		// Query looks like arbitrary string.
 		// Search using LIKE for matches of query
@@ -199,14 +198,6 @@ func (s *searchDB) followedAccounts(accountID string) *bun.SelectQuery {
 		Where("? = ?", bun.Ident("follow.account_id"), accountID)
 }
 
-// accountUsername returns a subquery that just selects
-// from account usernames, without concatenation.
-func (s *searchDB) accountUsername() *bun.SelectQuery {
-	return s.db.
-		NewSelect().
-		Column("account.username")
-}
-
 // accountText returns a subquery that selects a concatenation
 // of account username and display name as "account_text". If
 // `following` is true, then account note will also be included
@@ -242,11 +233,8 @@ func (s *searchDB) accountText(following bool) *bun.SelectQuery {
 	// different number of placeholders depending on
 	// following/not following. COALESCE calls ensure
 	// that we're not trying to concatenate null values.
-	//
-	// SQLite search is case insensitive.
-	// Postgres searches get lowercased.
-	d := s.db.Dialect().Name()
-	switch {
+
+	switch d := s.db.Dialect().Name(); {
 
 	case d == dialect.SQLite && following:
 		query = "? || COALESCE(?, ?) || COALESCE(?, ?) AS ?"
@@ -255,13 +243,13 @@ func (s *searchDB) accountText(following bool) *bun.SelectQuery {
 		query = "? || COALESCE(?, ?) AS ?"
 
 	case d == dialect.PG && following:
-		query = "LOWER(CONCAT(?, COALESCE(?, ?), COALESCE(?, ?))) AS ?"
+		query = "CONCAT(?, COALESCE(?, ?), COALESCE(?, ?)) AS ?"
 
 	case d == dialect.PG && !following:
-		query = "LOWER(CONCAT(?, COALESCE(?, ?))) AS ?"
+		query = "CONCAT(?, COALESCE(?, ?)) AS ?"
 
 	default:
-		panic("db conn was neither pg not sqlite")
+		log.Panicf(nil, "db conn %s was neither pg nor sqlite", d)
 	}
 
 	return accountText.ColumnExpr(query, args...)
@@ -385,10 +373,7 @@ func (s *searchDB) statusText() *bun.SelectQuery {
 
 	// SQLite and Postgres use different
 	// syntaxes for concatenation.
-	//
-	// SQLite search is case insensitive.
-	// Postgres searches get lowercased.
-	switch s.db.Dialect().Name() {
+	switch d := s.db.Dialect().Name(); d {
 
 	case dialect.SQLite:
 		statusText = statusText.ColumnExpr(
@@ -398,12 +383,12 @@ func (s *searchDB) statusText() *bun.SelectQuery {
 
 	case dialect.PG:
 		statusText = statusText.ColumnExpr(
-			"LOWER(CONCAT(?, COALESCE(?, ?))) AS ?",
+			"CONCAT(?, COALESCE(?, ?)) AS ?",
 			bun.Ident("status.content"), bun.Ident("status.content_warning"), "",
 			bun.Ident("status_text"))
 
 	default:
-		panic("db conn was neither pg not sqlite")
+		log.Panicf(nil, "db conn %s was neither pg nor sqlite", d)
 	}
 
 	return statusText

internal/db/bundb/search_test.go

@@ -46,6 +46,15 @@ func (suite *SearchTestSuite) TestSearchAccounts1HappyWithPrefix() {
 	suite.Len(accounts, 1)
 }
 
+func (suite *SearchTestSuite) TestSearchAccounts1HappyWithPrefixUpper() {
+	testAccount := suite.testAccounts["local_account_1"]
+
+	// Query will just look for usernames that start with "1HAPPY".
+	accounts, err := suite.db.SearchForAccounts(context.Background(), testAccount.ID, "@1HAPPY", "", "", 10, false, 0)
+	suite.NoError(err)
+	suite.Len(accounts, 1)
+}
+
 func (suite *SearchTestSuite) TestSearchAccounts1HappyNoPrefix() {
 	testAccount := suite.testAccounts["local_account_1"]
 
@@ -63,6 +72,14 @@ func (suite *SearchTestSuite) TestSearchAccountsTurtleFollowing() {
 	suite.Len(accounts, 1)
 }
 
+func (suite *SearchTestSuite) TestSearchAccountsTurtleFollowingUpper() {
+	testAccount := suite.testAccounts["local_account_1"]
+
+	accounts, err := suite.db.SearchForAccounts(context.Background(), testAccount.ID, "TURTLE", "", "", 10, true, 0)
+	suite.NoError(err)
+	suite.Len(accounts, 1)
+}
+
 func (suite *SearchTestSuite) TestSearchAccountsPostFollowing() {
 	testAccount := suite.testAccounts["local_account_1"]
 

internal/db/bundb/util.go

@@ -23,8 +23,10 @@
 
 	"github.com/superseriousbusiness/gotosocial/internal/cache"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
 	"github.com/superseriousbusiness/gotosocial/internal/paging"
 	"github.com/uptrace/bun"
+	"github.com/uptrace/bun/dialect"
 )
 
 // likeEscaper is a thread-safe string replacer which escapes
@@ -37,10 +39,29 @@
 	`_`, `\_`, // Exactly one char.
 )
 
+// likeOperator returns an appropriate LIKE or
+// ILIKE operator for the given query's dialect.
+func likeOperator(query *bun.SelectQuery) string {
+	const (
+		like  = "LIKE"
+		ilike = "ILIKE"
+	)
+
+	d := query.Dialect().Name()
+	if d == dialect.SQLite {
+		return like
+	} else if d == dialect.PG {
+		return ilike
+	}
+
+	log.Panicf(nil, "db conn %s was neither pg nor sqlite", d)
+	return ""
+}
+
 // whereLike appends a WHERE clause to the
 // given SelectQuery, which searches for
 // matches of `search` in the given subQuery
-// using LIKE.
+// using LIKE (SQLite) or ILIKE (Postgres).
 func whereLike(
 	query *bun.SelectQuery,
 	subject interface{},
@@ -54,11 +75,14 @@ func whereLike(
 	// zero or more chars around the query.
 	search = `%` + search + `%`
 
+	// Get appropriate operator.
+	like := likeOperator(query)
+
 	// Append resulting WHERE
 	// clause to the main query.
 	return query.Where(
-		"(?) LIKE ? ESCAPE ?",
-		subject, search, `\`,
+		"(?) ? ? ESCAPE ?",
+		subject, bun.Safe(like), search, `\`,
 	)
 }
 
@@ -78,11 +102,14 @@ func whereStartsLike(
 	// zero or more chars after the query.
 	search += `%`
 
+	// Get appropriate operator.
+	like := likeOperator(query)
+
 	// Append resulting WHERE
 	// clause to the main query.
 	return query.Where(
-		"(?) LIKE ? ESCAPE ?",
-		subject, search, `\`,
+		"(?) ? ? ESCAPE ?",
+		subject, bun.Safe(like), search, `\`,
 	)
 }