Option to disable decorator transform

Search Terms

decorator output

Suggestion

Decorators are always transformed. In some cases we critically need to preserve decorators in the output to feed into other tools, such as Babel.

All the other issues around this are closed, so I can't see what the plan is here. Adding a new flag to disable decorator transformation should be forward and backward compatible with any other implementation of decorators, old or new proposal.

Use Cases

• Use Babel 7 decorator support to compile the current decorator proposal
• Feed tsc output into other analysis tools that expect decorators in JS source.

Examples

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Start by reviewing the existing decorator transformation behavior and compiler-option conventions. Check how tsc output is consumed by Babel 7 and other analysis tools, then define the flag's behavior for preserving decorators and verify that existing decorator implementations remain compatible.