fix: add retry and error handling

src/index.ts

@@ -1,18 +1,56 @@
 import { ByteBuffer } from 'flatbuffers';
 import { WeatherApiResponse } from '@openmeteo/sdk/weather-api-response';
 
+const sleep = (ms: number) => new Promise(r => setTimeout(r, ms));
+
+async function fetchRetried(
+ url: string,
+ retries = 3,
+ backoffFactor = 0.5,
+ backoffMax = 2
+): Promise<Response> {
+ const statusToRetry = [500, 502, 504];
+ const statusWithJsonError = [400, 429];
+ let currentTry = 0;
+ let response = await fetch(url);
+
+ while (statusToRetry.includes(response.status)) {
+ currentTry++;
+ if (currentTry >= retries) {
+ throw new Error(response.statusText);
+ }
+ const sleepMs =
+ Math.min(backoffFactor * 2 ** currentTry, backoffMax) * 1000;
+ await sleep(sleepMs);
+ response = await fetch(url);
+ }
+
+ if (statusWithJsonError.includes(response.status)) {
+ const json = await response.json();
+ if ('reason' in json) {
+ throw new Error((json as { reason: string }).reason);
+ }
+ throw new Error(response.statusText);
+ }
+ return response;
+}
+
 async function fetchWeatherApi(
  url: string,
- params: any
+ params: any,
+ retries = 3,
+ backoffFactor = 0.2,
+ backoffMax = 2
 ): Promise<WeatherApiResponse[]> {
  const urlParams = new URLSearchParams(params);
  urlParams.set('format', 'flatbuffers');
- //console.log(`${url}?${urlParams.toString()}`);
- const response = await fetch(`${url}?${urlParams.toString()}`);
- const bb = await response.arrayBuffer();
- const fb = new ByteBuffer(new Uint8Array(bb));
-
- // TODO: retry, error handling
+ const response = await fetchRetried(
+ `${url}?${urlParams.toString()}`,
+ retries,
+ backoffFactor,
+ backoffMax
+ );
+ const fb = new ByteBuffer(new Uint8Array(await response.arrayBuffer()));
 
  const results: WeatherApiResponse[] = [];
  let pos = 0;

test/index.spec.ts

@@ -7,6 +7,7 @@ describe('openmeteo', () => {
  // 2 location data, with hourly temp and precip
  global.fetch = jest.fn(() =>
  Promise.resolve({
+ status: 200,
  arrayBuffer: () =>
  Promise.resolve(
  new Uint8Array([
@@ -92,3 +93,49 @@ describe('openmeteo', () => {
  });
  });
 });
+
+describe('openmeteo', () => {
+ describe('client', () => {
+ test('test_error', async () => {
+ global.fetch = jest.fn(() =>
+ Promise.resolve({
+ status: 400,
+ json: () => Promise.resolve({ reason: 'Some error' }),
+ })
+ ) as jest.Mock;
+ await expect(fetchWeatherApi('', {})).rejects.toThrow('Some error');
+ });
+ });
+});
+
+describe('openmeteo', () => {
+ describe('client', () => {
+ test('test_unknown_error', async () => {
+ global.fetch = jest.fn(() =>
+ Promise.resolve({
+ status: 400,
+ statusText: 'Other error',
+ json: () => Promise.resolve({}),
+ })
+ ) as jest.Mock;
+ await expect(fetchWeatherApi('', {})).rejects.toThrow('Other error');
+ });
+ });
+});
+
+describe('openmeteo', () => {
+ describe('client', () => {
+ test('test_retry', async () => {
+ global.fetch = jest.fn(() =>
+ Promise.resolve({
+ status: 500,
+ statusText: 'Internal server error',
+ })
+ ) as jest.Mock;
+ await expect(fetchWeatherApi('', {})).rejects.toThrow(
+ 'Internal server error'
+ );
+ expect(fetch).toHaveBeenCalledTimes(3);
+ });
+ });
+});