Directive

Rolldown will not add any directive for your output, here are the strategies when handling directives.

• When output.preserveModules is disabled, only directives in user defined entry module will be preserved repl
• When output.preserveModules is enabled, all directives will be preserved even the module is not user defined entry module. repl
• If the format is esm, 'use strict' directive will be filtered out whatever. repl