TS Async await fetch and io-ts

indicators-api.ts

    async getIndicatorData(indicator: WorldBankApiV2Indicators, country: Country, dateRange: string, perPage: number): Promise<DataPoint[]> {
        const response: Response = await fetch(`${this.getBaseIndicatorApiUrlFor(indicator, country)}?${WorldBankApiV2Params.FORMAT}=${WorldBankApiV2Formats.JSON}&${WorldBankApiV2Params.PER_PAGE}=${perPage}&${WorldBankApiV2Params.DATE}=${dateRange}`);

        const checkedResponse: Response = await this.checkResponseStatus(response);

        let jsonContent: unknown = await this.getJsonContent(checkedResponse);

        const validationResult = worldBankApiV2IndicatorResponseValidator.decode(jsonContent);

        ThrowReporter.report(validationResult);

        // from here on, we know that the validation has passed
        const dataPoints = (validationResult.value as WorldBankApiV2IndicatorResponse)[1];

        let retVal: DataPoint[] = [];
        if (dataPoints) { // we might not get anything back
            dataPoints.forEach(dataPoint => {
                retVal.push(new DataPoint(
                    dataPoint.date,
                    dataPoint.value
                ));
            });
        }
        return retVal;
    }