Components: Generate Drawer

Summary

Generate Drawer with its canonical contract, implementation, tests, stories, platform validation, and explicit package export so secondary edge content is available in the agentic library. Its key blocker is the shared overlay and positioning infrastructure, including light dismiss and focus return for overlay drawers.

Observed. drawer is entry drawer in the canonical catalog and has no
implementation in packages/agentic/components. Upstream describes it as: Secondary content surface that slides in from one edge of a layout. Covers type (Inline/Overlay), position (Start/End/Bottom), four sizes, header/body/footer anatomy, and dependency delegation to Button and Divider.

Goal

Generate the drawer component in
packages/agentic/components/src/components against the
canonical Fluent Flex spec, with the colocated coverage, stories, and platform
validation the package requires, and export it explicitly from
src/index.ts.

Stage

Stage 2 (beta). Wave 2 - overlay and popover stack.

Why it matters

Observed. The canonical catalog has 50 components and the agentic library has
generated 18. drawer is one of the 32 in the gap, enumerated in
the missing-components index.

Inferred. It belongs to the overlay stack, which is the largest single cluster of blocked components. Delivering the cluster converts a broad "not implementable" state into ordinary component work.

Observed current state

Canonical spec and source

Field	Value
Canonical spec	plugins/components/skills/drawer/SKILL.md with usage.md, web/tokens.yaml, web/accessibility.md, and web/interaction.md, at x3-design/fluent-design @ d334acf
Upstream tier	molecule
Upstream catalog key	drawer in component-map.yaml
Local staged spec	packages/agentic/components/specs/drawer - SPEC.md, usage.md, interaction.md, accessibility.md, tokens.yaml, blockers.md
Local implementation	None. No src/components/drawer directory exists

Closest existing FURN or V1 implementation

• packages/experimental/Drawer - Drawer.tsx, useDrawer.ts, Drawer.styling.ts, and DrawerTokens.ts. There are no platform-specific files, so this single implementation is the cross-platform and desktop reference.

Note on platform canon. Where a legacy package has platform-specific files, the
desktop path (.win32, .windows, .macos, or the unsuffixed cross-platform file)
is the compatibility reference. .ios, .android, and .mobile variants are not
treated as the cross-platform canonical implementation.

Local dependencies

• src/components/button - Observed present (component).
• src/components/divider - Observed present (component).

Known blockers

Observed (blockers.md, blocker class B in the index).

Two blockers were recorded: Modal and Alert drawers must trap focus over arbitrary child content and "pure RN does not provide a built-in focus-trap/FocusZone primitive that can enumerate and cycle through unknown descendants across Windows/macOS"; and return-focus-to-trigger is not self-contained because the spec defines no trigger ref or return-focus target prop and the trigger lives outside the component boundary.

Reassessment.

Valid. Both blockers are focus-lifecycle problems. Inferred: the first is resolved by the focus decision in focus-zone.md; the second is a spec gap that must be closed by adding an explicit return-focus target to the contract.

Scope

• Ingest or promote the spec into the component directory in the generated shape
  (SPEC.md plus a spec/ folder), per
  spec-ingestion-and-generation.md.
• Establish the public contract first: variants, slots, native props, accessibility,
  interaction states, and platform behavior.
• Implement the required file structure from
  src/components/AGENTS.md:
  drawer.types.ts, drawer.styles.ts, use*.ts, use*Styles.ts, render*.tsx, and
  the assembly module with a displayName.
• Style from Flex tokens first and record genuine token gaps rather than substituting
  unrelated values.
• Export the component, its public types, and the state, style, and render stages
  explicitly from src/index.ts under component-qualified unstable names.
• Close the recorded spec gap by adding an explicit return-focus target to the contract.
• Reuse the scrim and overlay host from popover and dialog for the Overlay type; the Inline type needs neither.

Out of scope

• Changing the contract of an existing generated component, unless this task explicitly
  calls for it above; raise it as its own item.
• Building shared infrastructure owned by another task: overlay hosting
  (popover), roving focus (focus-zone.md), spec
  ingestion (spec-ingestion-and-generation.md),
  or the coverage contract (component-test-strategy.md).
• Migrating any legacy FURN consumer onto this component.
• Mobile platform support; the applicable upstream companion is web, retargeted to
  React Native for Windows and macOS.

Deliverables

• src/components/drawer/ implementing the full required file structure.
• SPEC.md and a spec/ companion folder with provenance recording the upstream path,
  SHA, and ingestion date.
• Colocated drawer.test.tsx, drawer.types.test.ts, and drawer.stories.tsx.
• Snapshot coverage where the visual contract is state-dependent, or a recorded
  exemption.
• Explicit exports from src/index.ts, with src/index.test.ts updated.
• A changeset, per the repository's version management rules.
• A recorded readiness level with its supporting evidence.

Required coverage, stories, and platform validation

Runtime and type coverage:

• Both types across all three positions and all four sizes.
• Inline does not trap focus; Overlay does.
• Open and close transitions, and that closing returns focus to the recorded target.
• Header, body, and footer slots with arbitrary children.
• Escape dismisses the Overlay type.
• User style and handler forwarding, and that user styles are applied after component
  styles.
• Compile-time slot acceptance and any mutually exclusive props.

Stories: a typed Meta titled Components/Drawer, an args-driven Default, a
grouped Overview when the contract has several axes, one focused story per variant
axis, and an interactive story for each stateful axis. Self-driving axes expose
default<State> as the control; externally driven selection is owned by the story with
React.useState. Identity-changing axes are not exposed as controls.

Platform validation: the component's stories render and behave correctly on macOS
and on React Native Windows Fabric through apps/storybook,
including hover, pressed, disabled, focus, optional-slot, and constrained-content
scenarios. Add a stable root testID if the component joins the automated smoke set.

Acceptance criteria

• src/components/drawer exists with the required file structure and a displayName.
• Every variant axis in the component's SPEC.md is implemented, or a deviation is recorded in the spec.
• The component styles from Flex tokens, with any genuine token gap recorded rather than approximated.
• Focus feedback renders through FocusVisual; no outline* props and no React Native Windows native focus visuals are introduced.
• State precedence is explicit: disabled wins over pressed, which wins over hovered.
• Every stateful axis is classified as self-driving or externally driven, and both paths are covered.
• Runtime, type, and story coverage satisfy the package coverage contract.
• The component, its public types, and its pipeline stages are exported explicitly from src/index.ts, and src/index.test.ts covers them.
• The component's stories render on macOS and on React Native Windows Fabric.
• yarn workspace @fluentui-react-native/components format, lint, build, and test pass, and the Storybook bundle succeeds for both desktop platforms.
• A readiness level is recorded with its supporting evidence.
• A changeset is included.

Dependencies and ordering

• Blocked by popover for the overlay host, anchoring, light dismiss, and focus return.
• Gated by component-test-strategy.md: the component must satisfy the coverage contract on arrival rather than being retrofitted.
• Gated by readiness-model.md: the target readiness level must be stated before the work starts.
• Consumes the Infrastructure workstream (storybook-e2e.md) for automated macOS and Windows Fabric validation; until it lands, platform validation is manual.

Risks and open decisions

1. The Inline and Overlay types have materially different layout and focus behavior and may be better as two implementations behind one contract; decide explicitly.
2. Slide animations on Windows Fabric need on-device verification; a layout-driven animation can conflict with the persistent focus-visual rings the package mounts eagerly.

Evidence and references

• Upstream spec: plugins/components/skills/drawer/SKILL.md and
  components-index/SKILL.md
  at x3-design/fluent-design @ d334acf.
• Local staged spec and blocker record: packages/agentic/components/specs/drawer.
• Canonical implementations to follow: src/components/button
  for a styled higher-order component and src/primitives/icon
  for a primitive.
• Authoring rules: src/components/AGENTS.md and the
  agentic component authoring skill.
• Workstream context: Components README and
  the missing-components index.

Sources retrieved 2026-08-20.

Start with packages/agentic/components/specs/drawer/SPEC.md and its spec companions, then compare packages/experimental/Drawer with the requirements in src/components/AGENTS.md. Read the existing popover and dialog components before implementing the overlay path, and review the focus-zone decision for focus behavior. Done means the drawer files, colocated tests and stories, explicit index exports, changeset, platform validation, and required workspace checks are complete.