Pricing Differentiation: Implement the experiment code

[claudiucelfilip]

Part of https://linear.app/a8c/issue/DOTCOM-15460/design-for-the-pricing-grids-for-all-variants-incl-comparison-view

Proposed Changes

• adds an experiment assignment hook for the experiment
• adds the long, long stacked, and short versions of the feature sets
• adds the differentiation header

Why are these changes being made?

• we need this to apply the corresponding variations to the plans and comparison grids.

NOTE: Feature sets may not be final, but we can follow-up with updates afterwards.

Testing Instructions

• go to /setup/onboarding/plans
• go to the abacus of the calypso_plans_differentiators_20251210 experiment an assign yourself each of the following variations (may need delete the assignment from the localStorage each time) :

Control

• there should be no changes

Long feature set (long_set)

• you should see the full list of features

Long feature set, with differentiator header (long_set_diff)

• you should see the full list of features and the feature differentiator subheader

Long feature set, stacked (long_set_stacked)

• you should see the full list of features stacked using the Everything in X, plus:

Short feature set, stacked (short_set_stacked)

• you should see the full list of features stacked using the Everything in X, plus:

Sort feature set, stacked, with differentiator header (short_set_stacked_diff)

• you should see the shortened list of features stacked using the Everything in X, plus: and the feature differentiator subheader

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 tested accessibility for your changes? Ensure the feature remains usable with various user agents (e.g., browsers), interfaces (e.g., keyboard navigation), and assistive technologies (e.g., screen readers) (PCYsg-S3g-p2).
• 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]

Link to live branch is being generated...
Please wait a few minutes and refresh this page.

[matticbot]

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

App Entrypoints (~970 bytes added 📈 [gzipped])

name                   parsed_size           gzip_size
entry-stepper              +5030 B  (+0.3%)     +962 B  (+0.2%)
entry-main                 +5030 B  (+0.2%)     +970 B  (+0.2%)
entry-reauth-required      +5003 B  (+0.3%)     +962 B  (+0.2%)
entry-login                +5003 B  (+0.2%)     +962 B  (+0.1%)

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

Sections (~3441 bytes added 📈 [gzipped])

name                      parsed_size           gzip_size
jetpack-app                  +10454 B  (+2.3%)    +3659 B  (+2.6%)
plugins                      +10361 B  (+0.3%)    +3417 B  (+0.3%)
async-step-unified-plans      +3790 B  (+0.3%)    +1016 B  (+0.3%)
plans                         +3614 B  (+0.1%)    +1005 B  (+0.1%)
signup                         +176 B  (+0.1%)      +13 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 (~3827 bytes added 📈 [gzipped])

name                                             parsed_size           gzip_size
async-load-signup-steps-plans-theme-preselected     +10454 B  (+2.0%)    +3659 B  (+2.3%)
async-load-signup-steps-plans                       +10454 B  (+2.0%)    +3659 B  (+2.3%)
async-load-staging-site-sync-modal                    +485 B  (+0.2%)     +168 B  (+0.2%)

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.

[claudiucelfilip]

Temporary fix: The feature grouping mechanism would normally address this, but defining the groups while keeping the design's feature order is proving complicated. We can revisit once we have settled on the final features.

[matticbot]

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

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

• happy-blocks
• help-center
• odyssey-stats
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug update/plan-differentiation-experiment on your sandbox.