React 17 Dependency upgrade

[mannycarrera4]

React 17 Update

• Canvas Kit is planning to upgrade to React 17 in v7 . However, during the process we’ve found some interesting gotchas and we wanted let folks know about our findings and ask a few questions

• In React 17, they introduced a new version of JSX Transform. Although this is technically not a breaking change, it does introduce a complexity for teams using Babel, Emotion, and the /** @jsx jsx*/ pragma

• Canvas Kit uses this pragma because we have instances where we use the css prop from emotion. When upgrading to React 17, we saw the following error: pragma and pragmaFrag cannot be set when runtime is automatic.

• This error comes from babel from version 7.9 and greater when they introduced automatic runtime

• Because of the following errors, we’ve had to think about our solution and wanted to communicate to our consumers the path we’ve chosen to move forward with.

Work in Progress

• In v7 Canvas Kit will require teams to be on React version ^17.x or at least 16.14 for backwards compatibility and we will remove the jsx pragma and use of css props. This does not mean consumers can’t use the css prop, just that internally we will stop using it. This would require teams to upgrade other parts of their app including React, potentially Babel and any other side effects that come with it.

Questions for consumers

• Are teams planning to upgrade to React 17, if so how soon?
• Do you have any questions or concerns with this upgrade?
• What can we do to help support your upgrades to React 17?