spelling-variations/dist/index.d.ts

gives you a word's spelling variations with detection whether it's a UK (English, british) or US (American) variations, also gives you the preferred variation.

export default class SpellingVariations {
    data: AnalysisResult;
    constructor(word: string);
    scoreUK(): number;
    scoreUS(): number;
    hasVariations(): boolean;
    USVariations(): string[];
    UKVariations(): string[];
    UKPreferred(): string;
    USPreferred(): string;
    variations(): string[];
    commonVariation(): string;
    toUK(): string;
    toUS(): string;
    analyse(): AnalysisResult;
    analyze(): AnalysisResult;
}
export interface AnalysisResult {
    word: string;
    scoreUK: number;
    scoreUS: number;
    hasVariations: boolean;
    UKPreferred: string;
    USPreferred: string;
    commonVariation: string;
    UKVariations: string[];
    USVariations: string[];
    variations: string[];
    analyse: (input: string) => AnalysisResult;
    analyze: (input: string) => AnalysisResult;
}