Only allow headline ab testing on the US network front

[abeddow91]

What's changed?

Adds a guard to headline ab testing functionality so that it is only available on the US front. This is for the initial rollout only so that we can limit behaviour to a smaller subset of users.

Removal of this restriction will be covered by guardian/frontend#29129, once initial testing has finished.

This should not be merged until we are ready to rollout to production users.

Implementation notes

Checklist

General

• 🤖 Relevant tests added
• ✅ CI checks / tests run locally
• 🔍 Checked on CODE

Client

• 🚫 No obvious console errors on the client (i.e. React dev mode errors)
• 🎛️ No regressions with existing user interactions (i.e. all existing buttons, inputs etc. work)
• 📷 Screenshots / GIFs of relevant UI changes included

[github-actions]

Deploy build 9892 of cms-fronts::facia-tool to CODE

All deployment options

• Deploy build 9892 of cms-fronts::facia-tool to CODE
• Deploy parts of build 9892 to CODE by previewing it first
• What's on CODE right now?

---

From guardian/actions-riff-raff.

[simonbyford]

Looks good to me! Tested on CODE and everything works as expected

[Fweddi]

We might also need to adjust for the US network front in:

• facia-tool/fronts-client/src/components/FrontsEdit/CollectionComponents/Collection.tsx

  Line 450 in 694ae6b

  selectFeatureValue(state, 'headline-ab-testing') &&

• facia-tool/fronts-client/src/components/FrontsEdit/CollectionOverview.tsx

  Lines 246 to 249 in 1852a7a

  	headlineABTestingIsEnabled: selectFeatureValue(
  	state,
  	'headline-ab-testing',
  	),

We could include a test for fronts restriction if we wanted to (mirroring DCR).

[Fweddi]

We might also need to adjust for the US network front in:

• facia-tool/fronts-client/src/components/FrontsEdit/CollectionComponents/Collection.tsx

  Line 450 in 694ae6b

  selectFeatureValue(state, 'headline-ab-testing') &&

• facia-tool/fronts-client/src/components/FrontsEdit/CollectionOverview.tsx

  Lines 246 to 249 in 1852a7a

  	headlineABTestingIsEnabled: selectFeatureValue(
  	state,
  	'headline-ab-testing',
  	),

We could include a test for fronts restriction if we wanted to (mirroring DCR).

I've checked the original ticket and actually we were planning to remove the feature switch in this PR, which makes sense as we want everyone to be able to see the tests on the US front regardless of whether they have their feature switch enabled. Might be worth changing this PR to reflect that?

[abeddow91]

I've checked the original ticket and actually we were planning to remove the feature switch in this PR, which makes sense as we want everyone to be able to see the tests on the US front regardless of whether they have their feature switch enabled. Might be worth changing this PR to reflect that?

Thanks @Fweddi. As suggested, I've replaced all the switch checks for US front checks 👍