A developer attempted to reduce the size of all npm packages by 5% by replacing all spaces with tabs in package.json files. This seemingly minor change exploited a quirk in how npm calculates package sizes, which only considers the size of tarballs and not the expanded code. The attempt failed because while the tarball size technically decreased, popular registries like npm, pnpm, and yarn unpack packages before installing them. Consequently, the space savings vanished after decompression, making the effort ultimately futile and highlighting the disconnect between reported package size and actual disk space usage. The experiment revealed that reported size improvements don't necessarily translate to real-world benefits and underscored the complexities of dependency management in the JavaScript ecosystem.
Evan Hahn, driven by a desire to optimize the substantial size of node_modules folders and the time consumed by npm install, embarked on an ambitious project to reduce the size of all npm packages by a modest 5%. He hypothesized that many packages contained unnecessary files, like test files or example code, which were included in the published package despite not being needed for production use. This extra data, while potentially helpful for developers, contributes to larger download sizes and longer installation times for end users.
Hahn began by developing a tool named shrinkpack, designed to automate the process of identifying and removing these superfluous files. shrinkpack leveraged the common .npmignore file, often used to exclude files during publishing, and extended its functionality to allow for more granular control over file exclusions post-publication. This theoretically would allow users to install only the necessary files for production, leaving out development dependencies, examples, and documentation. The tool worked by wrapping the npm pack command, analyzing the resulting tarball, and creating a modified package with only the necessary files, effectively "shrinking" the package size.
He meticulously tested shrinkpack on a subset of npm packages to assess its efficacy and identify potential issues. Initial results were promising, showing significant size reductions in certain packages. However, as he broadened the testing scope, unforeseen complications arose. Many packages relied on non-standard file structures or build processes, which shrinkpack couldn't accommodate. Furthermore, some packages dynamically generated files during installation, making it impossible to predict and remove unnecessary files beforehand. The complexity of the npm ecosystem, with its diverse range of package structures and dependencies, proved to be a significant obstacle.
Another significant hurdle emerged concerning the integrity of package versioning and distribution. Modifying packages post-publication would necessitate a new mechanism for versioning these altered packages, ensuring compatibility and preventing unexpected behavior. The decentralized nature of npm further complicated this challenge, making it difficult to implement and enforce such a system across the entire ecosystem. Hahn acknowledged the risk of inadvertently breaking packages or introducing inconsistencies by modifying them after publication.
Despite initial optimism, Hahn ultimately concluded that his ambitious goal was, at least for now, unattainable. The inherent complexity of the npm ecosystem, coupled with the potential for unintended consequences, made a universal 5% size reduction impractical. He openly shared his findings, acknowledging the project's failure while emphasizing the valuable lessons learned about the intricate inner workings of npm and the challenges of large-scale software optimization. While his initial goal wasn't achieved, his work highlighted the ongoing need for improved efficiency in package management and sparked a discussion within the community about potential solutions.
Summary of Comments ( 47 )
https://news.ycombinator.com/item?id=42840548
HN commenters largely praised the author's effort and ingenuity despite the ultimate failure. Several pointed out the inherent difficulties in achieving universal optimization across the vast and diverse npm ecosystem, citing varying build processes, developer priorities, and the potential for unintended consequences. Some questioned the 5% target as arbitrary and possibly insignificant in practice. Others suggested alternative approaches, like focusing on specific package types or dependencies, improving tree-shaking capabilities, or addressing the underlying issue of JavaScript's verbosity. A few comments also delved into technical details, discussing specific compression algorithms and their limitations. The author's transparency and willingness to share his learnings were widely appreciated.
The Hacker News post "My failed attempt to shrink all NPM packages by 5%" generated a moderate amount of discussion, with several commenters exploring the nuances of the original author's approach and offering alternative perspectives on JavaScript package size optimization.
Several commenters questioned the chosen metric of file size reduction. One commenter argued that focusing solely on file size misses the bigger picture, as smaller file sizes don't always translate to improved performance. They suggested that metrics like parse time, execution time, and memory usage are more relevant, especially in a browser environment where parsing and execution costs often outweigh download times. Another commenter echoed this sentiment, pointing out that gzip compression already significantly reduces the impact of file size during transmission. They suggested that focusing on improving the efficiency of the code itself, rather than simply reducing its character count, would be a more fruitful endeavor.
There was some discussion around the specific techniques the original author employed. One commenter questioned the efficacy of removing comments and whitespace, arguing that these changes offer minimal size reduction while potentially harming readability and maintainability. They pointed out that modern minification tools already handle these tasks efficiently. Another commenter suggested that the author's focus on reducing the size of individual packages might be misguided, as the cumulative size of dependencies often dwarfs the size of the core code. They proposed exploring techniques to deduplicate common dependencies or utilize tree-shaking algorithms to remove unused code.
Some commenters offered alternative approaches to package size reduction. One suggested exploring alternative module bundlers or build processes that might offer better optimization. Another mentioned the potential benefits of using smaller, more focused libraries instead of large, all-encompassing frameworks. The use of WebAssembly was also brought up as a potential avenue for performance optimization, albeit with its own set of trade-offs.
A few commenters touched on the broader implications of package size in the JavaScript ecosystem. One expressed concern over the increasing complexity and size of modern JavaScript projects, suggesting that a greater emphasis on simplicity and minimalism would be beneficial. Another commenter noted the challenges of maintaining backwards compatibility while simultaneously pursuing optimization, highlighting the tension between stability and progress.
Finally, there were a couple of more skeptical comments questioning the overall value of the original author's experiment. One suggested that the effort expended on achieving a 5% reduction in package size might not be justified given the marginal gains. Another simply stated that the whole endeavor seemed like a "weird flex."