/**
* Parses a native-`accept`-style string (`".csv,.xlsx"`, `"text/csv"`,
* `"image/*"`, or any mix, comma-separated) and reports whether `file`
* matches it — the same three forms the browser's own file picker accepts,
* now also enforced on the drag-drop path (previously `accept` only
* constrained the native picker dialog and had no effect on drop).
*
* `file` may be a `DataTransferItem` cast as `File` (the dragenter-preview
* call site, before the drop payload has real `File` objects) - unlike
* `File`, `DataTransferItem` has no `.name`, only `.type`, so extension
* patterns (`.csv`) can't be evaluated pre-drop. By default an unresolved
* extension pattern counts as no match, since that's the correct behavior
* once real `File` objects are available at drop time. Pass
* `assumeExtensionMatch: true` to instead treat an unresolved extension
* pattern as a possible match — this is what dragenter preview uses so it
* doesn't render a false "reject" state for accept lists that are
* extension-only, when the file may well be accepted once dropped.
*/
export declare function matchesAccept(file:File,accept:string,assumeExtensionMatch?:boolean):boolean;