sqmicro-commons/test/retrier.test.js

Commons for SQ analytics microservices.

const wait = require('util').promisify(setTimeout);
const { Retrier } = require('../');

const LATENCY = 800; // ms

[{
    fails: 3,
    tries: 4
}, {
    fails: 3,
    tries: 3,
    expectError: true
}, {
    fails: 3,
    tries: 4,
    delay: 200 // while latency is 800
}].reduce(test, Promise.resolve());

function test(p, c) {
    const name = `${c.fails} failures, ${c.tries} tries with ${c.delay || 5000}ms delay`;
    const retrier = new Retrier(c.delay, c.tries);
    const action = getAction(c.fails);
    return p.then(
        () => {
            console.log(`START: ${name}`);
            return retrier.retry(action).then(
                () => console.log(`No error in ${name} ${c.expectError ? 'while it was EXPECTED!' : '.'}`),
                e => console.log(`Got ${c.expectError ? 'expected' : 'UNEXPECTED'} error in ${name}: ${e}`)
            ).then(
                () => console.log( `STOP ${name}\n\n`)
            );
        }
    );
}


function getAction(nFailures) {
    let ntries = 0;
    return async function action() {
        await wait(LATENCY);
        ntries++;
        if (ntries > nFailures) return 'yay!';
        throw Error(`Try #${ntries} fails for some reason`);
    };
}

process.on('unhandledRejection', (reason) => {
    reason.stack;
    console.error(`\nGot unhandled rejection: ${reason}`);
});