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import { expect, use } from 'chai';import { SinonFakeTimers, SinonStub, stub, useFakeTimers } from 'sinon';import { ExponentialBackoff, IterableBackoff, noJitterGenerator } from './backoff/Backoff';import { runInChild } from './common/util.test';import { handleAll, handleType, handleWhenResult, retry } from './Policy';
use(require('sinon-chai'));use(require('chai-as-promised'));
class MyErrorA extends Error {  constructor() {    super('Error A');  }}class MyErrorB extends Error {  constructor() {    super('Error B');  }}
describe('RetryPolicy', () => {  it('types return data correctly in all cases', async () => {    const policy = retry(handleAll, { maxAttempts: 1 });    const multiply = (n: number) => n * 2;    multiply(await policy.execute(() => 42));    multiply(await policy.execute(async () => 42));  });
  describe('setting backoffs', () => {    let s: SinonStub;    let clock: SinonFakeTimers;    let delays: number[];    beforeEach(() => {      clock = useFakeTimers();      delays = [];      s = stub().throws(new MyErrorA());    });
    afterEach(() => clock.restore());
    const makePolicy = (durations: number[]) => {      const p = retry(handleAll, {        maxAttempts: durations.length,        backoff: new IterableBackoff(durations),      });      p.onRetry(({ delay }) => {        delays.push(delay);        clock.tick(delay);      });      return p;    };
    it('sets the retry delay', async () => {      await expect(makePolicy([50]).execute(s)).to.eventually.be.rejectedWith(MyErrorA);      expect(delays).to.deep.equal([50]);      expect(s).to.have.been.calledTwice;    });
    it('sets the retry sequence', async () => {      await expect(makePolicy([10, 20, 20]).execute(s)).to.eventually.be.rejectedWith(MyErrorA);      expect(delays).to.deep.equal([10, 20, 20]);      expect(s).to.have.callCount(4);    });  });
  it('retries all errors', async () => {    const s = stub().onFirstCall().throws(new MyErrorA()).onSecondCall().returns('ok');
    expect(await retry(handleAll, {}).execute(s)).to.equal('ok');
    expect(s).to.have.been.calledTwice;  });
  it('filters error types', async () => {    const s = stub().onFirstCall().throws(new MyErrorA()).onSecondCall().throws(new MyErrorB());
    await expect(      retry(handleType(MyErrorA), { maxAttempts: 5 }).execute(s),    ).to.eventually.be.rejectedWith(MyErrorB);
    expect(s).to.have.been.calledTwice;  });
  it('filters returns', async () => {    const s = stub().onFirstCall().returns(1).onSecondCall().returns(2);
    expect(      await retry(        handleWhenResult(r => typeof r === 'number' && r < 2),        { maxAttempts: 5 },      ).execute(s),    ).to.equal(2);
    expect(s).to.have.been.calledTwice;  });
  it('permits specifying exponential backoffs', async () => {    const s = stub().returns(1);
    expect(      await retry(        handleWhenResult(r => typeof r === 'number'),        { backoff: new ExponentialBackoff({ generator: noJitterGenerator }), maxAttempts: 2 },      ).execute(s),    ).to.equal(1);
    expect(s).to.have.callCount(3);  });
  it('bubbles returns when retry attempts exceeded', async () => {    const s = stub().returns(1);
    expect(      await retry(        handleWhenResult(r => typeof r === 'number' && r < 2),        { maxAttempts: 5 },      ).execute(s),    ).to.equal(1);
    expect(s).to.have.callCount(6);  });
  it('bubbles errors when retry attempts exceeded', async () => {    const s = stub().throws(new MyErrorB());
    await expect(retry(handleAll, { maxAttempts: 5 }).execute(s)).to.eventually.be.rejectedWith(      MyErrorB,    );
    expect(s).to.have.callCount(6);  });
  it('does not unref by default', async () => {    const output = await runInChild(`      c.retry(c.handleAll, { maxAttempts: 1 }).execute(() => {        console.log('attempt');        throw new Error('oh no!');      });    `);
    expect(output).to.contain('oh no!');  });
  it('unrefs as requested', async () => {    const output = await runInChild(`    c.retry(c.handleAll, { maxAttempts: 1 }).dangerouslyUnref().execute(() => {      console.log('attempt');      throw new Error('oh no!');    });    `);
    expect(output).to.equal('attempt');  });
  it('stops retries if cancellation is requested', async () => {    const parent = new AbortController();    const err = new Error();    let calls = 0;    await expect(      retry(handleAll, { maxAttempts: 3 }).execute(({ signal }) => {        calls++;        expect(signal.aborted).to.be.false;        parent.abort();        expect(signal.aborted).to.be.true;        throw err;      }, parent.signal),    ).to.eventually.be.rejectedWith(err);    expect(calls).to.equal(1);  });
  it('fires onGiveUp', async () => {    const err = new MyErrorA();    const s = stub().throws(err);    const policy = retry(handleType(MyErrorA), { maxAttempts: 5 });    const onGiveUp = stub();    policy.onGiveUp(onGiveUp);
    await expect(policy.execute(s)).to.eventually.be.rejectedWith(MyErrorA);    expect(onGiveUp).to.have.been.calledWith({ error: err });  });});