Truncate columns after escaping

[chuwy]

snowplow/snowplow-snowflake-loader#42 introduced a column truncation in Transformer. But it truncates human-readable strings (with quotes and newlines) before they're escaped. As a result if string was truncated to 4096 and it has on " symbol that has to be truncated - this field will end up as 4097-characters length. Most common offender is se_label.

[chuwy]

Not possible to implement right now, as this escaping happens in circe's noSpaces

[chuwy]

Technically, we can count special symbols (\s) and extract number we get from final length.