feat(headless): refresh commerce recommendations server-side

[y-lakhdar]

Adding server-side rendering for commerce SSR package only.

• Updated headless-react package to reflect the new changes
• Updated headless-ssr-commerce sample to reflect the new changes

Features

Customizable Recommendation Controller

• Users can specify which recommendation controller to refresh by providing the recommendation key (as defined in the engine configuration).
• If no key is specified, the recommendation controller will not perform any queries.

• Supports selecting recommendations using the build method.

Recommendation Name Validation

• Validation against invalid recommendation names.
• Prevention of duplicate recommendation names.

Code to increase readability

Factory methods

Moved factory methods into dedicated files to avoid bloating the commerce-engine-ssr file.
Examples include:

• hydrated-state-factory.ts
• static-state-factory.ts

Core Engine Types

Centralized all core engine types into types/core-engine.ts.

Recommendation State Factories

Created dedicated factories for handling static and hydrated states for recommendations (recommendation-static-state-factory.ts).

Improved Controller Handling

Simplified the logic for building controllers based on solution type to eliminate complex, hard-to-read conditional blocks (677fd45)

https://coveord.atlassian.net/browse/KIT-3503

[github-actions]

Pull Request Report

PR Title

✅ Title follows the conventional commit spec.

Live demo links

• Storybook

• Playwright report

Bundle Size

File	Old (kb)	New (kb)	Change (%)
case-assist	241.4	241.4	0
commerce	346	346	0
search	413	413	0
insight	403.8	403.8	0
recommendation	253.6	253.6	0
ssr	406.5	406.5	0
ssr-commerce	358.3	361.1	0.8

SSR Progress

Use case	SSR (#)	CSR (#)	Progress (%)
search	39	44	89
recommendation	0	4	0
case-assist	0	6	0
insight	0	27	0
commerce	0	15	0

Detailed logs

search : buildInteractiveResult
search : buildInteractiveInstantResult
search : buildInteractiveRecentResult
search : buildInteractiveCitation
search : buildGeneratedAnswer
recommendation : missing SSR support
case-assist : missing SSR support
insight : missing SSR support
commerce : missing SSR support

[louis-bompart]

LGTM, nit pik.
It's quite complex tho for me to review this. @fbeaudoincoveo will probably understand it better than me.

[louis-bompart]

We go through (some) array items twice.
Replace

array.filter(filterFn).forEach(foreachCb)

by

for (const element of array) {
  if(!filterFn(element)) {
    continue;
  }
  foreachCb(element)
}

[alexprudhomme]

This is the reason why we duplicated all of the factories to separate the types from ssr-engine. In the case of recommendation, during fetchStaticState, we are adding a controller key array prop for recommendations you want to fetch. There will never be a case where ...params will be useful for recommendations so we removed it. It was best to create a seperate interface that can take in solutionType and do the logic in it.

[alexprudhomme]

Follow the trail here through fetchRecommendationStaticStateFactory to understand the filtering of the recommendation.