examples of typescript annotations

typescriptExampe.jsx

export type OptGroupNestedArrayTypes = Array<Array<string, Array<Array<string, string>>>>;

export type OptionGroupTypes = Array<{
    groupLabel: string,
    options: Array<{
        label: string,
        value: string,
    }>,
}>;

export const getOptGroupChoicesFromNestedArrays = (
    countries: OptGroupNestedArrayTypes,
): OptionGroupTypes => countries.map(item => ({
    groupLabel: item[0],
    options: item[1].map(choice => ({
        label: choice[1],
        value: choice[0],
    })),
}));

type ValuesTypes = { country: string, };

export const isUSA = (values: ValuesTypes): boolean =>
    constants.US_TERRITORIES.includes(values.country);

export const getGrossPayout = (
    requestedQuantity: number = 0,
    actualQuantity: number,
    commonPrice: number,
): number => {
    const quantity = requestedQuantity || Number(actualQuantity);
    return Math.ceil(Number(commonPrice) * quantity * 100) / 100;
};

export const getExerciseCost = (
    requestedQuantity: number,
    actualQuantity: number,
    exercisePrice: number = 0,
): number => {
    const quantity = requestedQuantity || Number(actualQuantity);
    return Math.ceil(Number(exercisePrice) * quantity * 100) / 100;
};