[Feature]: enforce explicit public API annotations via linter

[Hotell]

Area

React Components (@fluentui/react-components)

Describe the feature that you would like added

ATM our public APIs rely on TypeScript inference.

Example:

// Source
export const FluentProvider = React.forwardRef<HTMLElement, FluentProviderProps>((props, ref) => { ... }

⬇️ tsc emit ⬇️

// Emit
export declare const FluentProvider: React_2.ForwardRefExoticComponent<Omit<ComponentProps<FluentProviderSlots>, "dir"> & {
    applyStylesToPortals?: boolean | undefined;
    customStyleHooks_unstable?: Partial<{
        useAccordionHeaderStyles_unstable: (state: unknown) => void;
        useAccordionItemStyles_unstable: (state: unknown) => void;
        useAccordionPanelStyles_unstable: (state: unknown) => void;
        useAccordionStyles_unstable: (state: unknown) => void;
        useAvatarStyles_unstable: (state: unknown) => void;
        useAvatarGroupStyles_unstable: (state: unknown) => void;
        useAvatarGroupItemStyles_unstable: (state: unknown) => void;
        useAvatarGroupPopoverStyles_unstable: (state: unknown) => void;
        useBadgeStyles_unstable: (state: unknown) => void;
        useCounterBadgeStyles_unstable: (state: unknown) => void;
        useCardHeaderStyles_unstable: (state: unknown) => void;
        useCardStyles_unstable: (state: unknown) => void;
        useCardFooterStyles_unstable: (state: unknown) => void;
}>
}

This introduces various drawbacks:

• when TSC and API-Extractor emit changes during migration to new versions it affects every v9 package
• rolluped index.d.ts files are becoming bigger as inferred types are usually exapnded, if TSC cannot find proper type alias
• significant perf impact on emitting .d.ts

The ask here is to mitigate these drawbacks

Solution proposal:

we can enforce these behaviours via existing lint rules

• https://typescript-eslint.io/rules/explicit-module-boundary-types
• https://typescript-eslint.io/rules/explicit-function-return-type

After that is implemented and setup - we can enable --isolatedDeclarations tsc emit that is also supported by swc cli (via jsc.experimental.emitIsolatedDts )

• both js and d.ts emitted by 1 tool 💪

// Source
- export const FluentProvider = React.forwardRef<HTMLElement, FluentProviderProps>((props, ref) => { ... }
+ export const FluentProvider: ForwardRefComponent<FluentProviderProps> = React.forwardRef((props, ref) => {}

⬇️ tsc emit ⬇️

// Emit
- export declare const FluentProvider: React_2.ForwardRefExoticComponent<Omit<ComponentProps<FluentProviderSlots>, "dir"> & {
+ export declare const FluentProvider: Omit<ComponentProps<FluentProviderSlots>, 'dir'> & {
    applyStylesToPortals?: boolean | undefined;
+  customStyleHooks_unstable?: FluentProviderCustomStyleHooks;
-   customStyleHooks_unstable?: Partial<{
-       useAccordionHeaderStyles_unstable: (state: unknown) => void;
-        useAccordionItemStyles_unstable: (state: unknown) => void;
-        useAccordionPanelStyles_unstable: (state: unknown) => void;
-        useAccordionStyles_unstable: (state: unknown) => void;
-        useAvatarStyles_unstable: (state: unknown) => void;
-        useAvatarGroupStyles_unstable: (state: unknown) => void;
-        useAvatarGroupItemStyles_unstable: (state: unknown) => void;
-        useAvatarGroupPopoverStyles_unstable: (state: unknown) => void;
-        useBadgeStyles_unstable: (state: unknown) => void;
-        useCounterBadgeStyles_unstable: (state: unknown) => void;
-        useCardHeaderStyles_unstable: (state: unknown) => void;
-        useCardStyles_unstable: (state: unknown) => void;
-        useCardFooterStyles_unstable: (state: unknown) => void;
}>
}

Additional context

• chore(react-provider): Updating FluentProvider types to avoid implicit import in API definition #33590 (comment)
• [Feature]: create eslint rule to enforce style hook API consistency #30385

Have you discussed this feature with our team

No response

Validations

• Check that there isn't already an issue that requests the same feature to avoid creating a duplicate.

Priority

None