Gatsby v3 upgrade [Closes #2528]

[wackerow]

Description

https://www.gatsbyjs.com/docs/reference/release-notes/migrating-from-v2-to-v3/
Followed through documentation to upgrade to Gatsby v3. There are several breaking changes, but fortunately the repo is well prepared for this version upgrade and I didn't encounter a single breaking change that affected the codebase.

Ran yarn add gatsby@latest followed by yarn upgrade-interactive --latest

• gatsby-image [2.7.0] ❯ 3.0.0
• gatsby-plugin-lodash [3.6.0] ❯ 4.0.0
• gatsby-plugin-manifest [2.8.0] ❯ 3.0.0
• gatsby-plugin-matomo [0.8.3] ❯ 0.9.0
• gatsby-plugin-mdx [1.6.0] ❯ 2.0.1
• gatsby-plugin-react-helmet [3.6.0] ❯ 4.0.0
• gatsby-plugin-sharp [2.10.1] ❯ 3.0.1
• gatsby-plugin-sitemap [2.8.0] ❯ 3.0.0
• gatsby-plugin-styled-components [3.6.0] ❯ 4.0.0
• gatsby-remark-autolink-headers [2.7.0] ❯ 3.0.0
• gatsby-remark-copy-linked-files [2.6.0] ❯ 3.0.0
• gatsby-remark-images [3.7.0] ❯ 4.0.0
• gatsby-source-filesystem [2.7.0] ❯ 3.0.0
• gatsby-source-graphql [2.13.0] ❯ 3.0.0
• gatsby-transformer-csv [2.6.0] ❯ 3.0.0
• gatsby-transformer-remark [2.12.0] ❯ 3.0.0
• gatsby-transformer-sharp [2.8.0] ❯ 3.0.0

These are all the Gatsby libraries maintained by gatsbyjs/gatsby (plus the Matomo plugin).

Note on gatsby-plugin-image

From the docs: "While fluid, fixed, and gatsby-image will continue to work in v3, we highly recommend migrating to the new gatsby-plugin-image. Read the Migrating from gatsby-image to gatsby-plugin-image guide to learn more about its benefits and how to use it."
This does seem to include some syntax changes that we can implement, but are not requirements to the Gatsby v3 package upgrades. Can address this in separate issue.

Related Issue

#2528

[samajammin]

FYI @wackerow I created a couple separate issues related to this:

• Migrate off "gatsby-plugin-intl" #2777
• Migrate to "gatsby-plugin-image" #2778

[samajammin]

Closing in favor of #2780 - fixed merge conflicts & upgrade to react v17.