Unicode support: Value '👨🏿‍👩🏿‍👧🏿‍👦🏿' can't be stored to database column because exceeds length

[ezhaka]

Let say we have MySQL >= 5.0 and a column val emoji = varchar(16).

Starting from MySQL 5.0 a varchar column requires to define its size in symbols. If we consider '👨🏿‍👩🏿‍👧🏿‍👦🏿' emoji, we found that it has 11 symbols: man emoji, skin modifier, ZWJ (zero-width joiner), woman emoji, skin modifier, ZWJ, girl emoji, skin modifier, ZWJ, boy emoji, skin modifier.

Thus, this emoji can be inserted to val emoji = varchar(16).

However, if we try to insert '👨🏿‍👩🏿‍👧🏿‍👦🏿' there via exposed, we'll get java.lang.IllegalStateException: Value '👨🏿‍👩🏿‍👧🏿‍👦🏿' can't be stored to database column because exceeds length circlet.stickers.server.DBStickers$Sticker.symbol.columnType.colLength

Exposed/exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/statements/UpdateBuilder.kt

Line 21 in 21659ea

if (column.columnType is VarCharColumnType && value is String && value.length > column.columnType.colLength) {

The reason for this behavior is that in Java "👨🏿‍👩🏿‍👧🏿‍👦🏿".lenght == 19, because every emoji and skin modifier is considered as a pair of symbols (https://docs.oracle.com/javase/tutorial/i18n/text/unicode.html)