Infrastructure workstream

[JasonVMo]

Goal

Make desktop behavior and package-cost claims for the agentic component library
provable. Contributors and agents should use one supported desktop-driver and
Storybook workflow, CI results must distinguish native evidence from simulated
evidence, and component/theming bundle boundaries must be reproducible.

Status

In progress. Four of nine direct work items are closed; five remain open.

PR #4294
landed the shared Stage 1 foundation:

• Added the public @fluentui-react-native/desktop-driver package with a
  client-neutral W3C remote end, deterministic fake host, typed client,
  WebdriverIO runner, JSON CLI, bounded agent API, and confined artifacts. This
  closes #4258.
• Moved reusable Storybook desktop orchestration into the shared
  storybook-desktop CLI and removed app-local lifecycle scripts and the
  dedicated windows-tests harness.
• Added generated platform manifests, authenticated runtime identity, owned
  Storybook/Metro/driver lifecycles, and smoke --mode stories|stories-and-tests.
• Added pull-request smoke jobs for Windows Fabric and Win32 Paper with artifact
  upload. The merged validation traversed 136 Windows stories and 130 Win32
  stories; three authored plans passed through the fake target on each.
• Added initial Button, Checkbox, and Input role/state/value plans.

The bundle-size warning pipeline
(#4253),
Win32 Paper endpoint
(#4259), and
initial desktop Storybook pipelines
(#4279) were
already closed. PR #4295
also added cross-platform theme bundle scenarios that prove modern Flex paths
exclude reverse legacy compatibility payloads.

Current evidence boundary

stories traverses the supported catalog in a real native Storybook app.
stories-and-tests performs that native traversal and then runs authored plans
against the manifest-derived fake target. A green authored-plan result is
therefore not yet proof that native accessibility or interaction behavior
passed.

What is left

1. Add real native driver providers and pass the release gate on macOS, Windows
   Fabric, and Win32 Paper
   (#4257).
2. Run authored Storybook plans through those native providers, then define
   required jobs, retry limits, quarantine, artifact retention, and ownership
   (#4256).
3. Expand the accessibility schema beyond the initial role/state/value cohort
   to normalized accessible name, keyboard reachability, reports, and real
   macOS/Windows execution
   (#4255).
4. Finish the Windows smoke-harness disposition by proving that all required
   focus-crash coverage survives the retired harness
   (#4254).
5. Evaluate and deliver reliable window-scoped Windows Composition screenshots
   with locked-session diagnostics and provenance
   (#4260).
6. Promote bundle comparisons from warning/advisory output to reviewed required
   budgets after normal variance is established; add a follow-up issue if that
   work is no longer represented by closed Infrastructure: Add bundle-size and dependency regression gates #4253.

Work items

Status	Issue	Outcome or remaining work
Done	#4253 - Bundle-size and dependency regression gates	Cross-platform baselines and warning pipeline merged; required-budget promotion remains a rollup follow-up.
Open, partial	#4254 - Windows Jest smoke harness	Dedicated harness removed; native focus-interaction parity and durable ownership still need resolution.
Open, partial	#4255 - Story accessibility assertions	Initial Button, Checkbox, and Input role/state/value plans merged; broader schema and native proof remain.
Open, partial	#4256 - Storybook E2E pipelines	Windows/Win32 PR smoke, artifacts, shared macOS commands, native traversal, and fake-plan execution merged; native-plan parity and policy remain.
Open	#4257 - Real-platform driver proof	Implement native providers, eliminate false-green paths, publish compatibility evidence, and pass release gates.
Done	#4258 - Land desktop driver	Public Appium-free Stage 1 package and shared orchestration merged in PR #4294.
Done	#4259 - Win32 Paper Storybook	Endpoint is available and used by the shared smoke pipeline.
Open	#4260 - Windows Composition screenshots	Native capture evaluation and reliable evidence path remain.
Done	#4279 - Initial desktop Storybook pipelines	Initial pipeline foundation completed.

Beta exit criteria

• The public desktop-driver package is merged, built by the unified graph,
  and covered by package tests.
• Storybook exposes one shared CLI for manifest generation, native catalog
  traversal, fake authored-plan execution, and owned process lifecycles.
• Pull-request smoke jobs exercise Windows Fabric and Win32 Paper and upload
  artifacts.
• The Win32 Paper Storybook endpoint bundles and launches through the shared
  workflow.
• Cross-platform component and Flex-theme bundle baselines and dependency
  boundaries are checked and reported.
• At least one authored plan executes against a real native provider with
  truthful application-termination and artifact reporting.
• At least three components beyond Button have portable role, name, state,
  value, and keyboard assertions validated on a real desktop endpoint.
• Every false-green path in the driver release task is fixed or documented
  as an explicit limitation.
• The replacement suite preserves all required focus-crash coverage from
  the retired Windows harness.

Production exit criteria

• macOS, Windows Fabric, and Win32 Paper run the same authored manifest as
  required CI gates with matching digests.
• Retry, quarantine, expiry, artifact retention/redaction, and escalation
  policies have named owners.
• Backend prerequisites and compatibility ranges are published and tested.
• The driver package is released and validated by an external consumer
  without a globally installed Appium driver.
• Bundle growth budgets are required gates and baseline changes require
  reviewed rationale.
• Flex-only consumers exclude legacy and optional capabilities unless those
  capabilities are explicitly imported.
• Windows Fabric publishes window-scoped visual evidence with capture
  provenance and locked-session diagnostics; pixel differences remain
  evidence, not a pass/fail gate.
• Portable accessibility assertions are required for the initial component
  cohort on macOS and Windows.

Agent context

Architectural boundary

• The supported public contract is driver-client neutral and Appium-free.
• Platform providers may use platform-specific automation internally, but that
  detail must not leak into portable authored plans.
• A fake-host pass proves schema and orchestration determinism only.
• Native story traversal proves the application can enumerate and render the
  supported catalog, not that authored accessibility assertions ran natively.
• Deterministic gates and optional visual evidence must remain separate.

Current catalog exclusions

• Windows Fabric excludes Accordion and Callout because they still fail-fast
  the RNW 0.81 Fabric host during traversal.
• Win32 Paper excludes Accordion and ListItem; Callout remains covered on the
  Paper endpoint.

These exclusions must remain explicit in manifests and reports until the
underlying platform failures are resolved.

Sequencing

1. Native providers and false-green fixes precede required interactive jobs.
2. Accessibility normalization should stabilize before expanding the authored
   cohort.
3. Real Windows sessions should evaluate native screenshot fidelity before a
   host-level fallback is built.
4. Required bundle budgets should use observed variance rather than thresholds
   selected merely to make the first run pass.
5. macOS automation needs an authenticated, unlocked GUI session and stable
   Automation Mode; Windows native runs need an unlocked interactive desktop.

Merged evidence

• PR #4294 - Infrastructure: land the public desktop driver
• PR #4295 - Add appearance-aware Flex theme sources
• PR #4284 - Infrastructure: add bundle size checks and pipeline with warnings
• @fluentui-react-native/desktop-driver
• Shared storybook-desktop CLI and generated platform manifests
• Windows validation: 136 native stories and 3 fake-authored plans
• Win32 validation: 130 native stories and 3 fake-authored plans