@PabloZ Typescript compiles to ECMASCRIPT 5 which is then the input for Rhino which transpile that to Java, then Rhino is open source, then on any given moment NetSuite(proprietary) could decide to change Rhino source code and say you know what this JavaScript (standard) function would transpile to this custom Rhino code(java) then right there your type script would BREAK and NetSuite API which also got that change would continue to WORK...