Hide the top bar “Sign Up” button for OAuth flow

[jkmassel]

Proposed Changes

• Removes the "Sign Up" button from the top bar during the OAuth flow. It launches into the site creator and doesn't properly pass through the OAuth parameters, so it results in a dead end.

Why are these changes being made?

WP.com OAuth login is being used for iOS and Android users, and already rolled out to beta users. @tiagomar found this issue in a last-minute test session.

Testing Instructions

• Go to http://calypso.localhost:3000/log-in?client_id=2697&redirect_to=https%3A%2F%2Fpublic-api.wordpress.com%2Foauth2%2Fauthorize%3Fredirect_uri%3Dwordpress%253A%252F%252Fwpcom-authorize%26client_id%3D2697%26response_type%3Dtoken%26from-calypso%3D1 (it'll take a really long time to load) and note that the "Sign Up" button is hidden.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-130228

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-130228&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-130228&env=a8c-for-agencies

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

App Entrypoints (~17 bytes added 📈 [gzipped])

name         parsed_size           gzip_size
entry-main         +43 B  (+0.0%)      +17 B  (+0.0%)
entry-login        +43 B  (+0.0%)      +17 B  (+0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[dcalhoun]

The testing instructions worked for me. This approach looks good to me. 🚀

[dcalhoun]

I suppose this presumes that any request with client_id and redirect_to—whether it is the WordPress/Jetpack mobile app or otherwise—should no longer display this "Sign up" button. I don't perceive that to be a problem given the button does not pass along the redirect destination and, thus, creates the odd UX we hope to avoid with this change. 👍🏻

[jkmassel]

Yeah, I figured I'd fix this for other clients at the same time.

If this somehow is a regression for someone, we can scope it more tightly to just the client IDs we care about