Site Migrations: Update import flow reference on /sites dashboard

[sixhours]

Related to #90652 and https://github.com/Automattic/dotcom-forge/issues/7237

Proposed Changes

• Point /start/import to /setup/hosted-site-migration when coming from the /sites dashboard.

Tracking

We can follow the calypso_sites_dashboard_new_site_action_click_import event with a calypso_signup_start : flow: site-migration as a parameter to track incoming hits to this flow from the Site Dashboard.

There's also a ?source=sites-dashboard and ?ref=topbar query params carried over in the URL.

Why are these changes being made?

This is part of a project to redirect all references of /start/import to /setup/hosted-site-migration to leverage Migrate Guru for more reliable imports. paYKcK-4BA-p2

Testing Instructions

• Switch to this PR
• Navigate to /sites
• In the top left, click the arrow next to "Add new site"
• Click "Import an existing site"
• You should be brought to the new flow at /setup/hosted-site-migration

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 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-108302

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-108302&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-108302&env=a8c-for-agencies

[matticbot]

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

Sections (~56 bytes removed 📉 [gzipped])

name                     parsed_size           gzip_size
sites-dashboard                -86 B  (-0.0%)      -26 B  (-0.0%)
site-monitoring                -86 B  (-0.0%)      -26 B  (-0.0%)
import-hosted-site-flow        -86 B  (-0.0%)      -30 B  (-0.0%)
import-flow                    -86 B  (-0.0%)      -30 B  (-0.0%)
hosting                        -86 B  (-0.0%)      -26 B  (-0.0%)
github-deployments             -86 B  (-0.0%)      -26 B  (-0.0%)
dev-tools-promo                -86 B  (-0.0%)      -26 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.

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

• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug update/sites-dash-import on your sandbox.

[andres-blanco]

I noticed you mentioned a ?source=site-dashboard query param being added which I couldn't find. I'm curious about this and would like to understand it better.

I was able to find these two references:

• https://github.com/Automattic/wp-calypso/blob/trunk/client/sites-dashboard-v2/sites-dashboard-header.tsx#L107
• https://github.com/Automattic/wp-calypso/blob/trunk/client/sites-dashboard/components/sites-dashboard.tsx#L182

But those add a ref=topbar. Should we unify topbar and site-dashboard as ref? Maybe we can use one of them?

[sixhours]

I noticed you mentioned a ?source=site-dashboard query param being added which I couldn't find. I'm curious about this and would like to understand it better.

Ahh the reason you can't find it is because it's supposed to be sites-dashboard not site-dashboard, typo 🙃 Updated the original PR.

But those add a ref=topbar. Should we unify topbar and site-dashboard as ref? Maybe we can use one of them?

We could! I'm wondering if that could affect tracking for other projects, though. I'm inclined to leave them alone as long as we know we have some kind of ref param to go on.

[andres-blanco]

We could! I'm wondering if that could affect tracking for other projects, though. I'm inclined to leave them alone as long as we know we have some kind of ref param to go on.

Great, let's do that!

[andres-blanco]

LGTM