  The rise of user-contributed Open Source Software (OSS) ecosystems
demonstrate their prevalence in the software engineering discipline. Libraries
work together by depending on each other across the ecosystem. From these
ecosystems emerges a minimized library called a micro-package. Micro- packages
become problematic when breaks in a critical ecosystem dependency ripples its
effects to unsuspecting users. In this paper, we investigate the impact of
micro-packages in the npm JavaScript ecosystem. Specifically, we conducted an
empirical in- vestigation with 169,964 JavaScript npm packages to understand
(i) the widespread phenomena of micro-packages, (ii) the size dependencies
inherited by a micro-package and (iii) the developer usage cost (ie., fetch,
install, load times) of using a micro-package. Results of the study find that
micro-packages form a significant portion of the npm ecosystem. Apart from the
ease of readability and comprehension, we show that some micro-packages have
long dependency chains and incur just as much usage costs as other npm
packages. We envision that this work motivates the need for developers to be
aware of how sensitive their third-party dependencies are to critical changes
in the software ecosystem.
