Rspack 1.7: Speeding Up Builds with Rust

Rspack's Performance Leap

Rspack 1.7 signifies a substantial step forward for web developers seeking faster build times. The focus on improved SWC plugin compatibility is particularly noteworthy, as it addresses a significant pain point in the developer experience. The adoption of the cbor serialization scheme and the introduction of the Unknown variant are clever solutions to the challenges posed by evolving AST structures. The native support for importing assets as bytes is a welcome addition, streamlining common development tasks. The lazy compilation for dynamically imported modules, enabled by default, further contributes to a smoother developer workflow, especially for larger web applications. The stabilization of experimental features, particularly constant inlining and TypeScript enum inlining, demonstrates the project's maturity and its commitment to providing a stable and performant bundler.

However, there are limitations. While Rspack's performance gains are impressive, benchmarks still position it behind tools like esbuild and Rolldown. This suggests there is still room for optimization. The migration requirements for SWC Wasm plugins, requiring upgrades to be compatible with swc_core version 54 or above, could introduce friction for projects relying on older plugins. The article also doesn't provide enough details about the performance characteristics of lazy compilation, and the potential impacts on build size or runtime performance. The dependency on ByteDance, while not inherently negative, could raise concerns about long-term project sustainability and community governance, especially for developers outside of the ByteDance ecosystem.

Overall, Rspack 1.7 is a promising release. It offers tangible benefits in terms of build speed and developer experience. However, developers should carefully evaluate their existing plugin dependencies and consider the performance trade-offs before migrating. The continued evolution of Rspack and its ability to close the performance gap with other tools will be key to its long-term success. The ecosystem updates (Rsbuild, Rsdoctor, Rslib) further underscore the commitment to a complete toolchain, solidifying its place in the modern web development landscape.

Key Points

• Rspack 1.7 is the final 1.x release before the 2.0 transition, focusing on stability and plugin compatibility.
• Improved SWC plugin compatibility with cbor serialization and Unknown variant to avoid plugin breakage.
• Native support for importing assets as bytes using import fileBytes from './file.bin' with { type: 'bytes' };.
• Lazy compilation enabled by default for dynamically imported modules, speeding up dev server startup.
• Stabilization of experimental features like constant inlining and TypeScript enum inlining.
• Faster build times compared to webpack, but slower than esbuild and Rolldown.

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📖 Source: Rspack Releases Version 1.7: Final 1.x Update Before 2.0 Transition