源映射

¥Source maps

由于内联类型被空格替换，因此源映射对于堆栈跟踪中的正确行号来说不是必需的；并且 Node.js 不会生成它们。启用 --experimental-transform-types 时，默认情况下会启用源映射。

¥Since inline types are replaced by whitespace, source maps are unnecessary for correct line numbers in stack traces; and Node.js does not generate them. When --experimental-transform-types is enabled, source-maps are enabled by default.