test.retry.ts

// Copyright 2018 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import {AbortController} from 'abort-controller';
import assert from 'assert';
import nock from 'nock';
import {describe, it, afterEach} from 'mocha';
import {Gaxios, GaxiosError, GaxiosOptions, request} from '../src';

nock.disableNetConnect();

const url = 'https://example.com';

function getConfig(err: Error) {
  const e = err as GaxiosError;
  if (e && e.config && e.config.retryConfig) {
    return e.config.retryConfig;
  }
  return;
}

afterEach(() => {
  nock.cleanAll();
});

describe('🛸 retry & exponential backoff', () => {
  it('should provide an expected set of defaults', async () => {
    const scope = nock(url).get('/').times(4).reply(500);
    await assert.rejects(request({url, retry: true}), (e: Error) => {
      scope.done();
      const config = getConfig(e);
      if (!config) {
        assert.fail('no config available');
      }
      assert.strictEqual(config!.currentRetryAttempt, 3);
      assert.strictEqual(config!.retry, 3);
      assert.strictEqual(config!.noResponseRetries, 2);
      const expectedMethods = ['GET', 'HEAD', 'PUT', 'OPTIONS', 'DELETE'];
      for (const method of config!.httpMethodsToRetry!) {
        assert(expectedMethods.indexOf(method) > -1);
      }
      const expectedStatusCodes = [
        [100, 199],
        [408, 408],
        [429, 429],
        [500, 599],
      ];
      const statusCodesToRetry = config!.statusCodesToRetry!;
      for (let i = 0; i < statusCodesToRetry.length; i++) {
        const [min, max] = statusCodesToRetry[i];
        const [expMin, expMax] = expectedStatusCodes[i];
        assert.strictEqual(min, expMin);
        assert.strictEqual(max, expMax);
      }
      return true;
    });
  });

  it('should retry on 500 on the main export', async () => {
    const body = {buttered: '🥖'};
    const scopes = [
      nock(url).get('/').reply(500),
      nock(url).get('/').reply(200, body),
    ];
    const res = await request({
      url,
      retry: true,
    });
    assert.deepStrictEqual(res.data, body);
    scopes.forEach(s => s.done());
  });

  it('should not retry on a post', async () => {
    const scope = nock(url).post('/').reply(500);
    await assert.rejects(
      request({url, method: 'POST', retry: true}),
      (e: Error) => {
        const config = getConfig(e);
        return config!.currentRetryAttempt === 0;
      }
    );
    scope.done();
  });

  it('should not retry if user aborted request', async () => {
    const ac = new AbortController();
    const config: GaxiosOptions = {
      method: 'GET',
      url: 'https://google.com',
      signal: ac.signal,
      retryConfig: {retry: 10, noResponseRetries: 10},
    };
    const req = request(config);
    ac.abort();
    try {
      await req;
      throw Error('unreachable');
      // eslint-disable-next-line @typescript-eslint/no-explicit-any
    } catch (err: any) {
      assert(err.config);
      assert.strictEqual(err.config.retryConfig.currentRetryAttempt, 0);
    }
  });

  it('should retry at least the configured number of times', async () => {
    const body = {dippy: '🥚'};
    const scopes = [
      nock(url).get('/').times(3).reply(500),
      nock(url).get('/').reply(200, body),
    ];
    const cfg = {url, retryConfig: {retry: 4}};
    const res = await request(cfg);
    assert.deepStrictEqual(res.data, body);
    scopes.forEach(s => s.done());
  });

  it('should not retry more than configured', async () => {
    const scope = nock(url).get('/').twice().reply(500);
    const cfg = {url, retryConfig: {retry: 1}};
    await assert.rejects(request(cfg), (e: Error) => {
      return getConfig(e)!.currentRetryAttempt === 1;
    });
    scope.done();
  });

  it('should not retry on 4xx errors', async () => {
    const scope = nock(url).get('/').reply(404);
    await assert.rejects(request({url, retry: true}), (e: Error) => {
      const cfg = getConfig(e);
      return cfg!.currentRetryAttempt === 0;
    });
    scope.done();
  });

  it('should retain the baseUrl on retry', async () => {
    const body = {pumpkin: '🥧'};
    const url = '/path';
    const baseUrl = 'http://example.com';
    const scope = nock(baseUrl).get(url).reply(500).get(url).reply(200, body);
    const gaxios = new Gaxios({
      baseUrl,
    });
    const res = await gaxios.request({
      url,
      retry: true,
    });
    assert.deepStrictEqual(res.data, body);
    scope.done();
  });

  it('should not retry if retries set to 0', async () => {
    const scope = nock(url).get('/').reply(500);
    const cfg = {url, retryConfig: {retry: 0}};
    await assert.rejects(request(cfg), (e: Error) => {
      const cfg = getConfig(e);
      return cfg!.currentRetryAttempt === 0;
    });
    scope.done();
  });

  it('should notify on retry attempts', async () => {
    const body = {buttered: '🥖'};
    const scopes = [
      nock(url).get('/').reply(500),
      nock(url).get('/').reply(200, body),
    ];
    let flipped = false;
    const config: GaxiosOptions = {
      url,
      retryConfig: {
        onRetryAttempt: err => {
          const cfg = getConfig(err);
          assert.strictEqual(cfg!.currentRetryAttempt, 1);
          flipped = true;
        },
      },
    };
    await request(config);
    assert.strictEqual(flipped, true);
    scopes.forEach(s => s.done());
  });

  it('accepts async onRetryAttempt handler', async () => {
    const body = {buttered: '🥖'};
    const scopes = [
      nock(url).get('/').reply(500),
      nock(url).get('/').reply(200, body),
    ];
    let flipped = false;
    const config: GaxiosOptions = {
      url,
      retryConfig: {
        onRetryAttempt: async err => {
          const cfg = getConfig(err);
          assert.strictEqual(cfg!.currentRetryAttempt, 1);
          flipped = true;
        },
      },
    };
    await request(config);
    assert.strictEqual(flipped, true);
    scopes.forEach(s => s.done());
  });

  it('should support overriding the shouldRetry method', async () => {
    const scope = nock(url).get('/').reply(500);
    const config = {
      url,
      retryConfig: {
        shouldRetry: () => {
          return false;
        },
      },
    };
    await assert.rejects(request(config), (e: Error) => {
      const cfg = getConfig(e);
      return cfg!.currentRetryAttempt === 0;
    });
    scope.done();
  });

  it('should support overriding the shouldRetry method with a promise', async () => {
    const scope = nock(url).get('/').reply(500);
    const config = {
      url,
      retryConfig: {
        shouldRetry: async () => {
          return false;
        },
      },
    };
    await assert.rejects(request(config), (e: Error) => {
      const cfg = getConfig(e);
      return cfg!.currentRetryAttempt === 0;
    });
    scope.done();
  });

  it('should retry on ENOTFOUND', async () => {
    const body = {spicy: '🌮'};
    const scopes = [
      nock(url).get('/').replyWithError({code: 'ENOTFOUND'}),
      nock(url).get('/').reply(200, body),
    ];
    const res = await request({url, retry: true});
    assert.deepStrictEqual(res.data, body);
    scopes.forEach(s => s.done());
  });

  it('should retry on ETIMEDOUT', async () => {
    const body = {sizzling: '🥓'};
    const scopes = [
      nock(url).get('/').replyWithError({code: 'ETIMEDOUT'}),
      nock(url).get('/').reply(200, body),
    ];
    const res = await request({url, retry: true});
    assert.deepStrictEqual(res.data, body);
    scopes.forEach(s => s.done());
  });

  it('should allow configuring noResponseRetries', async () => {
    const scope = nock(url).get('/').replyWithError({code: 'ETIMEDOUT'});
    const config = {url, retryConfig: {noResponseRetries: 0}};
    await assert.rejects(request(config), (e: Error) => {
      const cfg = getConfig(e);
      return cfg!.currentRetryAttempt === 0;
    });
    scope.done();
  });

  it('should delay the initial retry by 100ms by default', async () => {
    const scope = nock(url).get('/').reply(500).get('/').reply(200, {});
    const start = Date.now();
    await request({
      url,
      retry: true,
    });
    const delay = Date.now() - start;
    assert.ok(delay > 100 && delay < 199);
    scope.done();
  });

  it('should respect the retryDelay if configured', async () => {
    const scope = nock(url).get('/').reply(500).get('/').reply(200, {});
    const start = Date.now();
    await request({
      url,
      retryConfig: {
        retryDelay: 500,
      },
    });
    const delay = Date.now() - start;
    assert.ok(delay > 500 && delay < 599);
    scope.done();
  });
});