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Add the first FxA Nimbus A/B test. Test 8 value proposition headings against the current control on the desktop QR promo in the authentication flow, and ship the updated promo design that makes room for the longer strings. Declare the promo-qr-mobile feature in the FML with two variables, enabled and branch. A single branch slug drives the heading and the QR code together, because each QR scans to its own Bitly link and a mismatched pair would misattribute the download. Every channel defaults to the control, so a Cirrus failure is a no-op, and an unknown slug falls back to the control, so a typo in Experimenter cannot break the promo. Declare all 9 headings as literal FTL ids so the l10n extraction finds them, and pick one at runtime with useFtlMsgResolver. The CTA moves below the QR and changes wording, so it takes a new -v2 id and translators re-translate rather than keep the old string. Rebuild the component to the updated design. The logo above the heading is gone, because the Bitly QR already embeds the Firefox glyph in its centre. The 230KB qr-mobile-kit.svg gives way to real fox vectors and a per-branch QR, about a 10x reduction. The heading used text-md, which is not in the font scale and so set no size at all; it is now text-sm font-bold. Report branch and nimbus_user_id on promo_qr_mobile.view. Cirrus reports enrollment itself, so the app must stamp nimbus_user_id on its own events for the analysis to join them. A CMS-supplied image carries no branch, so those users get the control copy and report no branch. The render waits on Nimbus so the control does not paint and then swap.
vbudhram
changed the title
bcolsson
approved these changes
Aug 26, 2026
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promo-qr-mobilefeature inconfigs/nimbus.yamlwith two variables,enabledandbranch. Every channel defaults to the control, so a Cirrus failure is a no-opbranches.ts, mapping each branch slug to its heading and its own QR code. One slug drives both, because each QR scans to a distinct Bitly link and a mismatched pair would misattribute the download. An unknown slug falls back to the controlen.ftlso l10n extraction finds them, and picks one at runtime withuseFtlMsgResolver. The CTA moves below the QR and changes wording, so it takes a newpromo-qr-mobile-description-v2idindex.tsxto the updated design. Drops the logo above the heading, since the Bitly QR already embeds the Firefox glyph. Replaces the 230KBqr-mobile-kit.svgwithfox-body.svg,fox-tail.svg, and a per-branch QR, roughly a 10x reductionbranchandnimbus_user_idextra keys topromo_qr_mobile.view. Cirrus reports enrollment itself, so the app must stampnimbus_user_idon its own events for analysis to join themNimbusContextso tests and stories can supply a branch without a network fetchIssue that this pull request solves
Closes: https://mozilla-hub.atlassian.net/browse/FXA-14273
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npx jest src/components/PromoQrMobile: 52 passed, 0 failed.npx jest src/lib/glean src/models/contexts: 188 passed, 0 failed.How to test:
NIMBUS_ENABLED=truein the root.envand bring up infrastructure so thecirruspm2 process runsaccounts.cirrus, featurepromo-qr-mobile, 9 branches?nimbusPreview=trueat 1024px or wider, on/,/signin, or/signuppromo_qr_mobile.viewcarriesbranchandnimbus_user_idBranch records come from Remote Settings, so enrollment cannot be hand-authored locally. Storybook has
Control,TreatmentB, andTreatmentAstories covering 1, 2, and 3-line headings without a Nimbus fetch.Needs a decision before merge: the CTA reads "Scan to download mobile app" per the Figma design, but the ticket table says "Scan to get the app" in all 9 rows. The CTA is constant across branches so it does not confound the experiment, but it does change shipped copy in every branch including the control.
Needs data review: the two new Glean extra keys.