Bob Matyas

Updating from Gatsby v2 to v3

Posted on    by  Bob Matyas


I recently updated my site from Gatsby v2 to v3. For the most part, it was a surprisingly painless transition. I followed along with the guide in the Gatsby docs which got me most of the way there, but there were a few issues not covered in the docs that I had to address.

I began by updating Gatsby to the latest version which took me from 2.x to 3. I ran this command:

npm install gatsby@latest

Next, I updated my dependencies. I ran:

npm outdated

and then installed the latest version of every plugin using:

npm install plugin-name@latest

Once I did this I had a few issues, so I decided to nuke the node_modules folder and rebuild it with a fresh install:

rm -rf node_modules
npm install

This reinstalled all the Node modules and fixed a couple of strange errors that were happening.

Once that was done, I got a number of error messages around exports and arrow functions:

9:1  warning  Anonymous arrow functions cause Fast Refresh to not preserve local component state.

       Please add a name to your function, for example:

       export default () => {}

       const Named = () => {}
       export default Named;


9:1  warning  Assign arrow function to a variable before exporting as module default

This was an easy fix to reflect some updated coding practices in components that hadn’t been touched in over a year.

Once I made all of the changes, everything built fine locally. However, moving it to my host I got errors with an out-of-date Node version which was causing the build to fail. Previously I was using Node v10.x whereas Gatsby v3 requires Node v12.x. This was a pretty easy fix and I just needed to change the Node version being used to build the site. For folks hosting on Netlify, you can do that by setting an environmental variable or adding a file to your repo.

From my perspective the most exciting changes in v3 are incremental builds and a new and more performant image plugin. I’m hoping that it is a bit easier to use as images had been a pain point in early versions of Gatsby.