test(agent): pin the new-tab suggestions - useSuggestions, getSuggestionLabel (Closes #1633)

[dmitrii-f-t27]

Closes #1633

What changed

One new file: trios/agent-server/apps/agent/entrypoints/newtab/index/lib/suggestions/useSuggestions.test.ts (the path the issue's Success Criteria names). The subject useSuggestions.ts is untouched.

The 2 exported symbols are exercised (2 it( blocks; 0 blocked):

• useSuggestions (1 test): the three suggestion sources are stubbed with full stand-ins steered by module-level fixtures, and the hook renders under renderToStaticMarkup inside a probe that serialises the sections it builds - the composition itself is what the pins read: nothing without a query; the search section behind the real provider name with the raw query trimmed, the case-duplicate dropped and the blank entries gone (Google Search:hello world/second, two flat items); the AI actions section ahead of search when tabs are selected; and the BrowserOS answer first when it has something to say.
• getSuggestionLabel (1 test): the text each kind of suggestion shows - the search query, the AI action name, the BrowserOS message.

No other suite of this job imports the stubbed modules (checked), and the subject is imported dynamically after the stand-ins register, so the file order cannot break the load. The provider lookup stays real - the pins read the section title it names.

How it was verified (FR-004)

• Passing run against the unmodified subject: 2 pass / 0 fail / 10 expect() calls, Ran 2 tests across 1 file.
• Deliberately broken copy (the AI Actions section title changed, valid syntax): 1 pass / 1 fail / 7 expect() calls. The subject was restored byte-identical (git checkout; git diff --name-only prints nothing) and the suite passes again.
• No network, database or container; no existing test modified or weakened. The file is biome-check clean. The local typecheck reports 59 errors - the pre-existing local base of this tree - and 0 mentions of the new file.
• Local reproducibility note (issue bun test cannot resolve @/ aliases once .wxt/tsconfig.json exists (wxt prepare output breaks the bun 1.3.6 runtime resolver) #1909): bun run typecheck runs wxt prepare, whose generated .wxt/tsconfig.json makes bun 1.3.6 stop resolving @/ aliases for test runs until that generated directory is removed. CI's Tests jobs never run wxt prepare; every run quoted above is from a checkout without .wxt/.

Not verified

• Nothing beyond the quoted local runs; the CI Tests / agent job re-runs the suite on this SHA.

Dmitrii Fedorov (@dmitrii-f-t27)

[tri-claw]

Summary by t27-bees

This PR adds a contract test file pinning the current behavior of useSuggestions and getSuggestionLabel from the new-tab suggestions module. The test stubs three suggestion sources and a storage seam with module-level fixtures, then renders the hook via renderToStaticMarkup to assert on the composed section structure and labels.

Worth a look

• trios/agent-server/apps/agent/entrypoints/newtab/index/lib/suggestions/useSuggestions.test.ts:13–21 — Mutable module-level fixtures (searchApiData, aiTabData, browserOSData) are reassigned between assertions inside a single it block. If the test runner ever parallelizes or reorders tests (or if another it is added later), this shared state will cause cross-test pollution and flaky failures.
• trios/agent-server/apps/agent/entrypoints/newtab/index/lib/suggestions/useSuggestions.test.ts:72–95 — The entire useSuggestions contract is verified in one it with sequential mutations. A failure at any expect stops the block, leaving fixtures mutated for any subsequent tests; splitting into independent it blocks with fresh fixtures per case would isolate failures.
• trios/agent-server/apps/agent/entrypoints/newtab/index/lib/suggestions/useSuggestions.test.ts:64–65 — The probe serializes sections by joining section.id, section.title, and mapped labels with : and / delimiters, then asserts with toContain. If a label or title ever contains those characters, the string matching can produce false positives/negatives.
• trios/agent-server/apps/agent/entrypoints/newtab/index/lib/suggestions/useSuggestions.test.ts:33–34 — The searchProviderStorage mock returns null for getValue but the real provider lookup stays active (useSearchProvider returns providerFixture = 'google'). If the subject later falls back to storage when the provider is missing, this test won't exercise that path.

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[github-actions]

✅ Tests passed — 3546/3616

Suite	Passed	Failed	Skipped
✅ agent	188/188	0	0
✅ build	9/9	0	0
✅ cdp-protocol	5/5	0	0
✅ eval	93/93	0	0
✅ server-agent	280/280	0	0
✅ server-api	2145/2214	0	69
✅ server-browser	6/6	0	0
✅ server-integration	10/11	0	1
✅ server-lib	279/279	0	0
✅ server-pglive	166/166	0	0
✅ server-root	68/68	0	0
✅ server-sim	8/8	0	0
✅ server-skills	31/31	0	0
✅ server-tools	244/244	0	0
✅ shared	14/14	0	0

View workflow run

[dmitrii-f-t27]

CI gates on this SHA:

• Tests / agent: pass — both suggestion pins run in the agent group.
• All other Tests/ matrix jobs pass*, including server-pglive (no flake rerun needed).
• Typecheck job: 19 errors = the known base count; 0 mentions of useSuggestions.test.ts in the job log.
• Biome job: red from base findings; 0 mentions of useSuggestions.test.ts in the job log.

Dmitrii Fedorov (@dmitrii-f-t27)