URLSearchParams to object

searchParamsParser.ts

function objToParams(obj: any) {
    let params = new URLSearchParams();
    for (let name in obj) {
        let value = obj[name];
        if (Array.isArray(value)) {
            for (let item of value) {
                params.append(name, item);
            }
        } else {
            params.set(name, value)
        }
    }
    return params.toString();
}

function paramsToObj<T>(paramsString: string, sample: T): T {

    const parseScalar = (paramValue: string, sampleValue: any) => {
        if (typeof sampleValue === 'boolean') {
            paramValue = ('' + paramValue).toLowerCase().trim();
            return ['true', 'yes', '1'].indexOf(paramValue) >= 0;
        } else if (typeof sampleValue === 'number') {
            return Number(paramValue);
        }
        return paramValue;
    }

    let params = new URLSearchParams(paramsString);
    let result = <any>{};
    for (let [name, value] of params) {
        let sampleValue = (<any>sample)[name];
        if (Array.isArray(sampleValue)) {
            let array = result[name] || [];
            array.push(parseScalar(value, sampleValue[0]))
            result[name] = array;
        } else {
            result[name] = parseScalar(value, sampleValue);
        }
    }
    return result;
}

let params = objToParams({
    description: 'xxx',
    tags: ['a', 'b'],
    isStarted: true
});
console.log(params);

let result = paramsToObj(params, {
    tags: [0],
    isStarted: true
});
console.log(JSON.stringify(result));