Detecting and removing bloated dependencies in CommonJS packages
Yuxin Liu, Deepika Tiwari, Cristian Bogdan, Benoit Baudry
TL;DR
This work investigates code bloat in server-side CommonJS Node.js packages and introduces a trace-based dynamic analysis, DepPrune, to detect and safely remove bloated dependencies. By monitoring OS file-system interactions during runtime, the approach identifies unaccessed dependencies and allows direct or full-scale debloating via updates to package.json and/or package-lock.json, respectively. On a curated dataset of 91 packages with 50,488 runtime dependencies, DepPrune discovers that 50.6% are bloated, with indirect dependencies contributing the majority of bloat; removing direct bloated dependencies cascades to many indirect removals while preserving functionality. The paper benchmarks DepPrune against state-of-the-art static (depcheck) and dynamic (Stubbifier) approaches, showing superior accuracy and fewer misclassifications, and discusses practical implications for development workflows and deployment lifecycles. Overall, the study demonstrates that runtime tracing provides a robust path to leaner dependency trees and reduced maintenance risks in dynamic JavaScript ecosystems.
Abstract
JavaScript packages are notoriously prone to bloat, a factor that significantly impacts the performance and maintainability of web applications. While web bundlers and tree-shaking can mitigate this issue in client-side applications, state-of-the-art techniques have limitations on the detection and removal of bloat in server-side applications. In this paper, we present the first study to investigate bloated dependencies within server-side JavaScript applications, focusing on those built with the widely used and highly dynamic CommonJS module system. We propose a trace-based dynamic analysis that monitors the OS file system to determine which dependencies are not accessed during runtime. To evaluate our approach, we curate an original dataset of 91 CommonJS packages with a total of 50,488 dependencies. Compared to the state-of-the-art dynamic and static approaches, our trace-based analysis demonstrates higher accuracy in detecting bloated dependencies. Our analysis identifies 50.6% of the 50,488 dependencies as bloated: 13.8% of direct dependencies and 51.3% of indirect dependencies. Furthermore, removing only the direct bloated dependencies by cleaning the dependency configuration file can remove a significant share of unnecessary bloated indirect dependencies while preserving functional correctness.
