jsperf-img-svc/lib/test-case.js

A simple micro service for loading jsperf result charts as a static image

'use strict';

const
	_ = require('lodash'),
	Promise = require('bluebird'),
	FeedParser = require('feedparser'),
	request = require('request'),
	highland = require('highland'),
	moment = require('moment'),
	MD5 = require('crypto-js/md5'),
	cache = require('./cache'),
	shared = require('./shared'),
	config = require('./config');

module.exports = class TestCase {
	constructor(slug, rev){
		this.slug = slug;
		this.feed = `${config.remoteBase}/${slug}.atom`;
		this.rev = (rev == 'latest' ? rev : (_.parseInt(_.isUndefined(rev) ? 0 : rev) || 1));
		this.feedKey = `feed:${MD5(this.feed).toString()}@${this.rev}`;
	}
	fetch(){
		const client = cache.getClient();
		return cache
			.expired(client, this.feedKey)
			.then(() => {
				return cache
					.read(client, this.feedKey)
					.then(json => JSON.parse(json));
			})
			.catch(() => {
				return new Promise((resolve, reject) => {
					return request
						.get(this.feed)
						.pipe(new FeedParser({addmeta: false}))
						.on('error', reject)
						.pipe(highland())
						.flatten()
						.through(shared.streamToPromise)
						.then((feedArray) => {
							let index = (this.rev == 'latest' ? feedArray.length : this.rev) - 1;
							return feedArray[index];
						})
						.then(resolve);
				})
			})
			.then((revision) => {
				this.guid = revision.guid;
				this.link = revision.link;
				this.date = moment(revision.date).toISOString();

				let imageId = MD5(`${this.guid}${this.date}`).toString();
				this.image = `/cache/image/${imageId}`;
				this.imageKey = `image:${imageId}`;

				// don't wait for cache write to complete
				cache.write(client, this.feedKey, JSON.stringify(revision), config.feedTTL);
			})
			.return(this);
	}
};