You do tell TypeScript which runtime you're targeting, and that's how it decides how to compile it. You either set `target` in your tsconfig.json, or you provid

You do tell TypeScript which runtime you're targeting, and that's how it decides how to compile it. You either set `target` in your tsconfig.json, or you provide `--target` on the command line. Docs: https://www.typescriptlang.org/docs/handbook/compiler-options.html https://www.typescriptlang.org/docs/handbook/compiler-option...