src protected virtual override OutStream doWriteInclude(OutStream out, Str module, Str path)

src virtual const override Str ext := "js"

src new make(File nodeDir)

src virtual const override File moduleDir := this.nodeDir.plus(`esm/`)

src virtual const override Str moduleType := "esm"

src virtual override OutStream writeExports(OutStream out, Str[] exports)

src virtual override Void writePackageJson(Str:Obj? json)