Breaking Changes Explanation for 9.0.0

[mmilleruva]

I am upgrading my site to use 9.0.0 and I see a list of breaking changes documented here:
https://github.com/googleapis/google-auth-library-nodejs/releases

My question is what do they break and what changes do developers need to incorporate to resolve those breaking changes?

I have tried to review the individual PRs to understand what the breaking change is, but most of them have no description, or I don't have access to the documentation referenced.

[danielbankhead]

Hey @mmilleruva,

Excellent question - here's collection of breaking changes and how to adapt to the latest version:

• We've dropped support for Node 12 and require Node 14+.
• We've dropped support for .p12 certs feat!: remove support for conversion of *.p12 to *.pem node-gtoken#452
  • They have been long deprecated and removing support greatly reduces the size of all of the libraries as we can drop node-forge as a dependency altogether
• We use a more generic Transporter type rather than DefaultTransporter across the clients. This means if someone is relying on DefaultTransporter properties, they should explicitly instantiate and set that as an AuthClient's transport feat!: make transporter attribute type more generic #1406 (comment)
• We drop support for browsers without TextEncoder support build!: remove arrify and fast-text-encoding #1583

In general, we don't expect most folks to be affected.