A flag to replace removed syntax with blank space

[marco-ippolito]

🔍 Search Terms

Blank space ErasableSyntax Node.js Strip Types Type Stripping

✅ Viability Checklist

• [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code
• [x] This wouldn't change the runtime behavior of existing JavaScript code
• [x] This could be implemented without emitting different JS based on the types of the expressions
• [x] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• [x] This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• [x] This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

A new flag to replace removed syntax during transpilation with blank space. Similarly to http://github.com/bloomberg/ts-blank-space and https://swc.rs/docs/references/wasm-typescript used in Node.js. This would remove the need of sourcemaps. It can only be used in conjuction with --erasableSyntaxOnly

📃 Motivating Example

Example:

const foo: string = "Hello World";

becomes:

const foo            = "Hello World";

💻 Use Cases

1. What do you want to use this for? Remove the need of sourcemaps after transpilation.
2. What shortcomings exist with current approaches? None other than only a subset of syntax defined by an existing flag can be stripped.
3. What workarounds are you using in the meantime? swc and tsblankspace