[automated] Improve PR CI time with selective test execution

[radical]

[automated] Selective PR CI enforcement is active after #19687 and #19688. Track rollout accuracy, performance, trigger-map maintenance, and related workflow improvements.

Enable selective test execution

• Land [automated] fix(ci): select installer jobs and loose CI dependencies correctly #19687 — improve selector rules for installer jobs and loose CI dependencies.
• Land [automated] ci: run only tests affected by pull request changes #19688 — enable selective test and job execution while retaining the run-full-ci escape hatch.

Monitor and react

• [automated] Monitor selective PR CI accuracy after enforcement #19787 tracks the bounded accuracy audit.
• [automated] Investigate renamed-file handling in selective PR CI #19786 tracks renamed-file handling.

During rollout, check for missed required tests, unnecessary selections, and CI regressions. Update the trigger map when issues are found, and use full CI or disable enforcement whenever selection safety is uncertain.

Measure performance

Compare representative PR CI timing after selective test execution with runs from before selection was enabled. Use enough runs to account for normal CI variance and record whether selective execution materially improves PR time.

Keep the trigger map current

• Add Copilot review guidance—repository instructions, a skill, or both—that identifies pull requests which should update trigger files.
• Have that guidance suggest trigger-map updates when tests, projects, CI jobs, workflows, or loose CI inputs change.

Related workflow structure

• Land [automated] ci: streamline test job fan-out #19761 — streamline selector-friendly test job fan-out, tracked by [automated] Streamline selective CI test job fan-out #19788.

[joperezr]

🤖 Aspire triage pass — 2026-08-27 20:51 UTC

Area: area-engineering-systems, area-pipelines
Kind: feature-request (engineering tracking issue)
Repro: none — internal PR-CI optimization tracking work
Affected version(s): N/A — engineering/CI infrastructure, not a shipped product surface
Severity: S4 — CI throughput improvement (selective test execution rollout + monitoring)

Urgency: ⚪ backlog — no milestone
Reason: engineering tracking issue, not a regression or S1/S2 product bug; open milestones are 13.5.x, 13.6, 14.0 (no 13.4.x/13.5 open)

Suggested owner(s): self-filed tracking issue by the area's primary contributor (author excluded per policy)
Evidence:

• Author is the top recent area-engineering-systems contributor (merged Fix broken main CI #19677, fix(release): Restore WinGet publication with .NET 9 wingetcreate #19551, [automated] Enable WinGet publishing by default in release pipeline #19533, [release/13.5] fix(release): Restore WinGet publication with .NET 9 wingetcreate #19509 in the last 30d) and owns the selective-test-execution rollout referenced here
• No independent owner assigned; a human can confirm ownership if this needs to leave the author's queue

Confidence: medium
Needs human?: no