Motivation

single-spa@5 is focused on performance and developer experience. The bundle size for single-spa has gone down from ~25kb to ~15kb ungzipped (6kb to 5kb gzipped). We have created new error pages which give in-depth information about console errors, and link to those pages in both development and production builds. We now publish single-spa.dev.js files for easier debugging of single-spa itself. And we have removed all of our deprecated APIs (that have been deprecated and not documented for about two years).

Migration path

99% of single-spa users can simply upgrade to single-spa@5.0.0-beta.0 without any changes to their code and everything will work exactly as it was before. You'll just benefit from a smaller bundle size and better DX for errors. See the breaking changes below for the few breaking changes that exist. We encourage early-adopters to try out single-spa@5 and let us know if they notice anything broken in it. In our testing so far, we have seen no problems with it.

Installation

npm install --save single-spa@beta

CDN url: https://cdn.jsdelivr.net/npm/single-spa@beta/

Breaking changes

• Removing the declareChildApplication and unloadChildApplication apis that have been deprecated for two years (#390). You can use the registerApplication and unloadApplication apis instead.
• Removing err.name and err.appName from errors passed to single-spa error handlers (#404)

Features

• Switching to "error codes" to communicate what went wrong with single-spa applications. The error codes link to pages such as https://single-spa.js.org/error/?code=1 which give in-depth explanations of what is happening.
• Adding support for warningMillis timeout configuration. This lets you configure or turn off the "application's mount lifecycle did not resolve or reject in 1000 milliseconds" console warnings. (#389)

Fixes

• Fixing link to the new error code documentation pages (#406)
• Fixing error debugging info for parcel-related messages (#407)

Perf

• Reducing bundle size with babel/rollup changes (#392)
• Reducing bundle size by removing class syntax (#393)
• Reducing bundle size with various refactors (#396)
• Reducing bundle size by switching from object spread syntax to a manual object assign (#401)

Maintenance

• Adding prettier and speeding up pre-commit (#391)
• Fixing build by upgrading NodeJS version in Travis (#394)
• Updating rollup.config.js to easier way of doing multiple outputs (#403)