Reader: reader and account flows set Reader as the user's default landing page

[DustyReagan]

Related to https://github.com/Automattic/loop/issues/341

Proposed Changes

• This PR saves a new user's landing page preference to the Reader when they sign-up from /start/reader/user-social or /start/account/user-social

Why are these changes being made?

• When a user signs up via /discover or as a user account with no blog/site, it makes sense that their default landing page should be the Reader, since their site was created through social interaction and they have no sites.

Testing Instructions

• Use Calypso Live or localhost
• Go to /discover and click "Sign Up" in the upper right. This will take you to sign up via /start/reader/user-social
• Sign up using any method, try several.
• After sign-up is complete, you'll be redirected to /reader. If you go to /me/account, you'll see your "Default Landing Page" is set to "The Reader"
• Similarly, if you try to "Like" or "Comment" on a blog while logged out, you'll be prompted to create an account using /start/account/user-social Creating an account from this flow should also set your "Default Landing Page" to "The Reader"

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-132363

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-132363&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-132363&env=a8c-for-agencies

[matticbot]

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

Sections (~273 bytes added 📈 [gzipped])

name                  parsed_size           gzip_size
signup                     +614 B  (+0.2%)     +159 B  (+0.2%)
update-design-flow         +569 B  (+0.0%)      +78 B  (+0.0%)
link-in-bio-tld-flow       +569 B  (+0.0%)      +62 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Async-loaded Components (~1362 bytes removed 📉 [gzipped])

name                                                     parsed_size           gzip_size
async-load-signup-steps-site-picker                           -631 B  (-0.3%)     -213 B  (-0.3%)
async-load-signup-steps-domains                               -631 B  (-0.1%)     -260 B  (-0.1%)
async-load-signup-steps-difm-site-picker                      -631 B  (-0.3%)     -208 B  (-0.3%)
async-load-calypso-blocks-jitm-templates-sidebar-banner       -631 B  (-1.2%)     -227 B  (-1.2%)
async-load-calypso-blocks-jitm-templates-notice               -631 B  (-1.2%)     -228 B  (-1.2%)
async-load-calypso-blocks-jitm-templates-default              -631 B  (-1.2%)     -226 B  (-1.2%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

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.

[DustyReagan]

I'm not sure this is the best place for this, but I'm struggling to find another place to put this after the user has been created.

[eoigal]

Works well!