A panel dissects CommonJS versus ES Modules, touching on Node, Deno, Bun, and how evolving standards, tools, and runtimes impact JavaScript's future.
Episode Description
A panel dissects CommonJS versus ES Modules, touching on Node, Deno, Bun, and how evolving standards, tools, and runtimes impact JavaScript’s future.
Episode Summary
This conversation centers on whether CommonJS is detrimental to modern JavaScript and why the community should prioritize ES Modules (ESM). Beginning with housekeeping announcements and introductions, the panel shares varied perspectives on backward compatibility, acknowledging that legacy projects often need CommonJS but arguing that ESM offers compelling advantages like static analysis and better tree-shaking. They also highlight the influence of new runtimes such as Deno and Bun, which aim to move beyond Node’s historical baggage while still grappling with compatibility concerns. Discussions delve into the real-world implications of switching module systems, especially for projects that have remained untouched for years. They also cover security topics like bot attacks and offline use cases through advanced browser APIs. By the end, the group underscores that, while ESM is the preferred path forward, CommonJS remains embedded in countless codebases—a delicate balance that requires both empathy for existing projects and encouragement to adopt modern standards.
Chapters
00:00 - 06:00 • Welcome and Introductions
In this opening segment, the hosts kick off the discussion by greeting listeners and inviting community members to join the conversation. They emphasize their usual practice of encouraging audience participation, explaining how both beginners and seasoned developers can contribute valuable insights. There’s a brief mention of the weekly format, with the show happening every Wednesday. The hosts introduce themselves and their roles, covering their work on various developer advocacy initiatives, podcasts, and JavaScript frameworks. They also touch on the importance of building an inclusive community where anyone can share experiences and learn. Overall, it sets the stage for an informal yet informative talk, highlighting the open, collaborative nature that defines the show’s atmosphere.
06:00 - 12:00 • Newsletter Focus: Is CommonJS Bad?
Attention turns to the week’s newsletter theme—“Is CommonJS Bad for JavaScript?”—sparked by a recent Deno blog post. The panel outlines the background of CommonJS (CJS) and how it became a default module system for Node. They compare that legacy to the newer ES Modules (ESM) standard, which aims for better interoperability and performance. Discussion highlights potential friction arising when bridging CJS and ESM, especially with modern bundlers like Vite, which often assume ESM by default. The hosts note that while CommonJS has served its purpose for years, developers increasingly encounter migration headaches. They tease a deeper dive into the tensions between backward compatibility and forward progress, foreshadowing the central debate of the episode.
12:00 - 18:00 • Edgio’s New Podcast and Bot Attack Examples
The conversation takes a brief detour to discuss Edgio’s newly launched podcast “Behind the Edge.” A representative from Edgio outlines its first episode on bot attacks and high-profile examples like the Ticketmaster fiasco during Taylor Swift’s ticket sales. They explore how bots can overwhelm online platforms, buying out inventory before real users can even access it. Emphasizing the real-world consequences for businesses and consumers, they highlight how better security measures can mitigate these issues. While it’s a slight shift from the main CJS-versus-ESM topic, the segment broadens the discussion to show how server-side technologies, including Node or alternative runtimes, must consider performance and security challenges like bot infiltration.
18:00 - 24:00 • CommonJS vs. ESM: A Friction Point
Refocusing on the core debate, the panel delves deeper into where CommonJS can create friction in modern projects. They mention how older libraries or codebases still rely heavily on CJS, leading to conflicts with more contemporary ecosystems that prefer ESM. They also outline the complexities of packaging a single library to support both systems, noting that it can bloat tooling configurations and complicate developer workflows. While most agree that ESM is the more “future-proof” choice, they acknowledge how widespread CJS code remains, especially in enterprise scenarios. This chapter sets up the tension: whether to keep supporting CJS indefinitely or push more aggressively toward an ESM-only ecosystem.
24:00 - 30:00 • Node.js Backward Compatibility and Python 2 Analogy
Here, the panel draws parallels to Python’s long transition from Python 2 to Python 3, highlighting how prolonged backward compatibility can stagnate progress. They question whether Node should similarly set a deprecation timeline for CJS. Some argue that being too accommodating traps the ecosystem in a suboptimal state, preventing the language from taking full advantage of advanced tooling. Others maintain that abrupt changes would break countless projects overnight, making a more nuanced approach necessary. This chapter underscores that while many developers see a pressing need for a clean break, the reality of mission-critical legacy apps complicates any swift move away from CJS.
30:00 - 36:00 • Deno’s Approach and the Role of Bundlers
Discussion shifts to Deno’s stance on CommonJS and how the Deno team has historically avoided or minimized CJS support, urging new projects to stick with ESM. Panelists highlight Deno’s design philosophy of “batteries included,” emphasizing built-in features like TypeScript support and secure defaults. They then link this to modern bundlers such as Rollup and Vite, explaining how ESM enables tree-shaking—an optimization nearly impossible with CJS. While some see Deno as a fresh start, free from Node’s historical baggage, others view it as an entirely different environment that may still need a bridging solution for older packages. This segment addresses whether Deno’s stricter ESM stance is feasible for widespread adoption or too idealistic given existing Node-centric workflows.
36:00 - 42:00 • Bun as a Node-Compatible Alternative
Bun enters the spotlight as another emerging runtime. The conversation explores how Bun aims for Node compatibility while trying to modernize performance and developer experience. Panelists note that, unlike Deno, Bun embraces CommonJS for broader legacy support, potentially limiting its ability to diverge significantly from Node’s paradigms. They evaluate BUN’s focus on speed, especially for tasks like startup times, and how it might nudge Node to improve. Still, the group questions whether Bun can truly differentiate if it inherits many of Node’s constraints, including the setTimeout API differences. This chapter highlights how new runtimes often face trade-offs between blazing new trails and supporting established norms.
42:00 - 48:00 • Tools, Tree-Shaking, and Real-World Examples
In this section, the discussion zooms in on tree-shaking—removing unused code automatically—and how it breaks with CJS. By design, CJS exports aren’t easily statically analyzed, making it nearly impossible for bundlers to prune dead code. Panelists point to libraries like Redux or RxJS, which can be challenging to optimize even under ESM. They also highlight specific real-world scenarios, like older testing frameworks that still rely on CJS or advanced build configurations. The group underscores how these mismatches can lead to developer confusion, wasted bandwidth, or complex packaging that extends beyond a single tool’s capabilities. This deep dive shows just how practical the impact of module format choices can be.
48:00 - 54:00 • Developer Mindshare and Dark Matter Projects
Panelists address a phenomenon they call “dark matter developers”: teams who maintain older systems far longer than the cutting edge of tech Twitter might realize. Large enterprises or understaffed projects often don’t upgrade dependencies for years, letting CJS-based codebases run until absolutely forced to change. Participants debate whether the community’s emphasis on new runtimes and ES modules overlooks the day-to-day realities of teams that just need stable, working software. They also discuss how bundler authors or framework maintainers try to smooth this transition but often face pushback from entrenched legacy systems. Ultimately, the conversation reveals a tension between progress and pragmatism that shapes the broader ecosystem’s pace of change.
54:00 - 60:00 • Web Standards and Future Parity
Here, the talk expands to how new web standards might erase the line between server and client, referencing advanced browser APIs. The group ponders whether Node or other runtimes will increasingly conform to browser-like features, or if unique server APIs will persist indefinitely. They cite new file system APIs for the web, such as OPFS (Origin Private File System), which hint at a future where complex tasks and data manipulation no longer require a dedicated backend. While these innovations promise more flexible offline capabilities and security considerations, panelists note that they could blur the lines of what “web development” even means, potentially merging the best of both worlds at scale.
60:00 - 66:00 • Security Concerns, Bot Traffic, and Offline Functionality
Revisiting security and performance briefly, the panel touches on how advanced APIs or new runtimes might help mitigate or accelerate certain risks. They connect the earlier discussion of bot attacks to the fact that if more logic is shifted to the client—and if new file system APIs and offline caches proliferate—security models must adapt. They also emphasize that robust solutions, whether on Node, Deno, or Bun, must consider real-world threats like ticket scalping bots. With the potential for more persistent client-side capabilities, developers might need fresh strategies for validation, authentication, and enforcement. While still primarily a tangent, this segment underscores that module format choices can’t be isolated from broader security implications.
66:00 - 72:00 • Breaking the Web vs. Evolving It
Can the ecosystem “just drop CommonJS”? The conversation here highlights the “Don’t Break the Web” principle, reminding everyone that changes to widely used APIs must be handled carefully. Indeed, forcibly removing CommonJS would cripple a colossal portion of Node-based applications. The panel wrestles with the idea of sunsetting CommonJS over a long timeline, drawing parallels to other major migrations like Python 2 to 3 or even the phasing out of Internet Explorer. While new projects arguably shouldn’t start with CommonJS, many participants accept the reality that a total deprecation demands a highly orchestrated, multi-year approach—one that might rely on community consensus and thoughtful maintainership from Node core contributors.
72:00 - 78:00 • Personal Tangents and The Edges of Tech
Around this time, the show drifts into more lighthearted territory as speakers share personal anecdotes, from hacking stories to comedic references about lock-picking and infiltration. Though not strictly about CJS or ESM, these tangents reveal the culture of the guests—a blend of deep technical interest and playful curiosity. They also demonstrate how security, both physical and cyber, is a shared fascination among many developers. This portion keeps the conversation lively and personal, illustrating that the ethos of experimentation extends beyond pure coding. It underscores how interwoven security, community, and even physical infiltration stunts can be in developer culture.
78:00 - 84:00 • Revisiting Tooling Decisions and Brainstorming
After the tangents, participants circle back to the core question of frameworks and runtimes. They re-evaluate how new tools, like Bun or Deno’s packaging systems, influence the Node ecosystem. Some express skepticism that BUN’s decision to maintain Node compatibility limits true innovation, while Deno’s stricter approach reduces friction for ESM but alienates older code. The group collectively brainstorms how best to move the ecosystem forward without alienating developers stuck in CommonJS. They also consider testing frameworks, offline scenarios, and emerging specs that could unify server-client development. This chapter synthesizes earlier discussions into a forward-looking perspective on the evolving tooling landscape.
84:00 - 90:00 • Final Opinions on CJS Deprecation
In this block, the conversation crystallizes around whether CommonJS deserves an explicit end-of-life. The consensus is nuanced: while ESM is the future and should be encouraged, entirely dropping support overnight is neither realistic nor empathetic. The panel endorses a more methodical approach, potentially including deprecation warnings and long timelines so projects have ample warning. Mentions of Python’s multi-year shift reemerge, suggesting Node or the JavaScript community could learn from those lessons. Speakers also argue for stronger guidance from maintainers and tooling authors to discourage new CJS usage. This sets the stage for a more balanced roadmap that respects both innovation and stability.
90:00 - 94:26 • Wrap-Up and Closing Thoughts
As the show winds down, the hosts thank listeners and participants, reiterating the value of open discussion. They invite everyone to follow each other on social media to stay informed on future developments and community-driven insights. There’s a final acknowledgment that while the conversation has been lively, the question of “Is CommonJS bad for JavaScript?” doesn’t have a simple yes or no answer. Instead, it demands an ongoing dialogue among library maintainers, runtime creators, and everyday developers. In closing, the hosts reaffirm the show’s collaborative spirit, encouraging further debate, knowledge sharing, and real-world experimentation to shape the next era of JavaScript development.