Conversion to TypeScript has been going inside Google for a year at least. Angular team started to do slides in TypeScript about year ago.
What I do find annoying is the constant rebranding the teams in Google tries to do to TypeScript. Angular team called TypeScript + runtime typechecking a "AtScript". Now this document calls something of similar a "SoundScript".
Can't the Google just admit it's using TypeScript? Adding a runtime checking doesn't change the fact it's just a TypeScript.
It is absolutely not TypeScript. SoundScript is supposed to have a sound type system (one that can be the basis for optimizations). TypeScript was designed with an unsound type system.
What I do find annoying is the constant rebranding the teams in Google tries to do to TypeScript. Angular team called TypeScript + runtime typechecking a "AtScript". Now this document calls something of similar a "SoundScript".
Can't the Google just admit it's using TypeScript? Adding a runtime checking doesn't change the fact it's just a TypeScript.