[PM-34546] Add integration tests for Notifications POST /send endpoint

[justindbaur]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-34546

📔 Objective

Adds integration tests for the POST /send endpoint on the Notifications service.

The tests form a three-part contract:

1. PushAsync_ProducesASupportedPayload — the real NotificationsApiPushEngine must produce a payload matching a format in SupportedPayloads, catching wire-format changes at CI time.
2. PostSend_RoutesPayloadToCorrectHubGroup — every format in SupportedPayloads is accepted by the live /send endpoint and routed to the correct SignalR hub group.
3. PushAsync_Notification_RoutesToClientTypeGroup — a PushAsync call with a specific ClientType in the notification payload routes end-to-end to the correct client-type-scoped SignalR group.

SupportedPayloads also serves as the rolling-upgrade compatibility list: old formats are kept for at least one release so that senders on the previous version still work after Notifications is deployed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.66%. Comparing base (1c0cf67) to head (d15fb49).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8171      +/-   ##
==========================================
+ Coverage   63.38%   63.66%   +0.28%     
==========================================
  Files        2337     2338       +1     
  Lines      101456   101524      +68     
  Branches     9167     9179      +12     
==========================================
+ Hits        64303    64637     +334     
+ Misses      34942    34672     -270     
- Partials     2211     2215       +4     

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[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: APPROVE

Test-only change adding integration coverage for POST /send on the Notifications service, plus a NotificationsApplicationFactory that pairs an in-memory Notifications host with a real in-memory Identity server for token issuance. Both findings from the previous review round were addressed in d15fb49: RoutingCases is now the single source of truth with SupportedPayloads derived from it, and the captured payload is read from the actual request body via ReadAsStringAsync, so the recorded literals are now the real camelCase wire format JsonContent.Create emits. Routing expectations for all nine cases were re-traced against HubHelpers and match the production switch, including the client-type-scoped group behavior and the installation-before-user precedence for PushType.Notification.

Code Review Details

No findings at or above the reporting threshold.

Minor, not worth an inline comment: NotificationsApplicationFactory.CreateClient() remains unused — a test asserting POST /send rejects an unauthenticated request would put it to work and cover the Internal policy on this internal ingress endpoint. Also note the XML <summary> carrying the rolling-upgrade guidance now sits on the RoutingCase record declaration rather than the RoutingCases array a maintainer would edit.

Dependency Changes

Package	Change	Ecosystem
Microsoft.AspNetCore.Mvc.Testing	New to this project (10.0.8), already used in IntegrationTestCommon and five other test projects at the same pinned version	NuGet

Lock file (test/Notifications.Test/packages.lock.json) was regenerated alongside the manifest change.

[withinfocus]

Works for me, but see the AI review comment for some suggestions that it didn't bubble up into dedicated suggestions.