Signup: remove unused domain-transfer flow

[ciampo]

Related to #78948

Proposed Changes

Remove unused domain-transfer flow from the Signup framework

Why are these changes being made?

The flow is not in use anymore, replaced by an equivalent /setup flow: see #78948

Testing Instructions

• Visit /start/domain-transfer
• Both on trunk and on this PR, notice that the page is redirected to /setup/domain-transfer

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-134127

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-134127&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-134127&env=a8c-for-agencies

[matticbot]

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

Sections (~110 bytes removed 📉 [gzipped])

name                        parsed_size           gzip_size
async-step-unified-domains       -512 B  (-0.0%)     -110 B  (-0.0%)
update-design-flow               -271 B  (-0.0%)      -56 B  (-0.0%)
signup                           -271 B  (-0.1%)      -56 B  (-0.1%)
home                             -271 B  (-0.0%)      -56 B  (-0.0%)
async-step-unified-plans         -271 B  (-0.0%)      -56 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 (~54 bytes removed 📉 [gzipped])

name                             parsed_size           gzip_size
async-load-signup-steps-domains       -241 B  (-0.0%)      -54 B  (-0.0%)

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.

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• blaze-dashboard
• command-palette-wp-admin
• help-center
• newsletter
• notifications
• odyssey-stats
• whats-new
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug remove/signup-domain-transfer-flow on your sandbox.

[tyxla]

Good one 👍

Looks like there might be a few more cleanup opportunities related to this flow:

wp-calypso/client/lib/signup/step-actions/index.js

Lines 1284 to 1287 in f82b613

	const isTransferSelectedInDomainTransferFlow =
	'domain-transfer' === flowName &&
	signupDependencies?.domainItem &&
	isDomainTransfer( signupDependencies.domainItem );

wp-calypso/client/lib/signup/test/step-actions.js

Lines 219 to 243 in f82b613

	test( 'should remove a step when a domain transfer is selected in the `domain-transfer` flow', () => {
	const stepName = 'plans';
	const nextProps = {
	isPaidPlan: false,
	sitePlanSlug: 'sitePlanSlug',
	flowName: 'domain-transfer',
	signupDependencies: {
	domainItem: {
	product_slug: 'domain_transfer',
	},
	},
	submitSignupStep,
	};
	expect( flows.excludeStep ).not.toHaveBeenCalled();
	expect( submitSignupStep ).not.toHaveBeenCalled();
	isPlanFulfilled( stepName, undefined, nextProps );
	expect( submitSignupStep ).toHaveBeenCalledWith(
	{ stepName, cartItems: null, wasSkipped: true },
	{ cartItems: null }
	);
	expect( flows.excludeStep ).toHaveBeenCalledWith( stepName );
	} );