Rspack Unveils Version 1.7: The Last Minor Update Before Major Changes Ahead!
Rspack, the innovative web bundler crafted using Rust, has just rolled out its latest version, 1.7, which serves as the concluding minor update in its 1.x series. This release is particularly significant as it sets the stage for the upcoming version 2.0 transition. Designed to be a high-performance alternative to webpack, Rspack aims to enhance developer experience by stabilizing existing features and improving compatibility with plugins.
In this new version, Rspack introduces key enhancements that include better compatibility with SWC plugins, native support for importing assets as bytes, and the stabilization of various experimental features. Additionally, a noteworthy change is the default activation of lazy compilation for dynamically imported modules in web applications, which can significantly improve development speed.
One of the standout improvements in Rspack 1.7 is the enhanced SWC plugin compatibility. Previously, developers faced challenges when updating SWC Wasm plugins due to frequent changes in the Abstract Syntax Tree (AST) structure, which often rendered existing plugins incompatible. To overcome this hurdle, the Rspack team contributed crucial compatibility updates to the SWC community. These updates include adopting the cbor serialization scheme to replace the older version-sensitive rkyv, as well as adding an Unknown variant for enum types within the AST to bolster fault tolerance. With Rspack 1.7, upgrading SWC is expected to preserve the functionality of existing plugins built on earlier SWC versions.
Another exciting feature introduced in Rspack 1.7 is the native support for the Import Bytes proposal. This allows developers to import assets directly as Uint8Array, making it easier to decode them using TextDecoder. The syntax follows a straightforward pattern:
javascript
import fileBytes from './file.bin' with { type: 'bytes' };
const decoder = new TextDecoder('utf-8');
const text = decoder.decode(fileBytes);
Moreover, Rspack now enables lazy compilation by default for dynamically imported modules, streamlining the build process for web applications. This adjustment minimizes the number of modules loaded during the initial build, leading to faster server startup times. For those who have specific requirements, there is an option to disable this feature by setting lazyCompilation to false.
Many experimental features have also reached stable status in this release. The constant inlining optimization is now stable and automatically enabled in production builds. The previous experiments.inlineConst option has been deprecated in favor of optimization.inlineExports. Additionally, TypeScript enum inlining optimization and type re-export checks have transitioned to stable status, marking a significant step forward in functionality.
For developers looking to migrate to Rspack 1.7, it’s essential to pay close attention to the versions of SWC plugins being used. Those utilizing SWC Wasm plugins need to upgrade their plugins to be compatible with swc_core version 54 or higher to prevent potential build issues. The Rspack team has provided detailed guidance on addressing version mismatches in their FAQ documentation.
Rspack aims to be a viable alternative to webpack, boasting significantly faster build times. A user on Medium shared their experience, highlighting a remarkable 70% decrease in build time after switching from webpack to Rspack—dropping local builds from 1.7 minutes to just 30 seconds. Another team at Mews reported an impressive reduction in startup time from three minutes to a mere ten seconds, translating to an 80% improvement. Despite these achievements, benchmarks from the Rolldown project reveal that while Rspack outpaces webpack, it still lags behind tools such as esbuild and Rolldown in certain performance metrics.
In conjunction with the Rspack 1.7 update, the broader Rstack ecosystem has also seen enhancements. Rsbuild 1.7 now features runtime error overlays and asset size diff reporting, Rsdoctor 1.4 has introduced a new treemap view for bundle analysis, and Rslib 0.19 has achieved stabilization of ESM output in bundle mode.
Developed by ByteDance, Rspack is an open-source project that seeks to maintain compatibility with webpack's API while leveraging Rust’s performance capabilities. This makes it an excellent choice for teams eager to enhance build speeds without stepping away from the familiar webpack environment.
