🎉 Initial commit

Author: Juliano Rafael

.gitignore

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+# package directories
+node_modules
+jspm_packages
+
+# Serverless directories
+.serverless
+
+# Environment variables
+env.yml

README.md

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+# TheReactDev
+
+The function that feeds @TheReactDev twitter.
+
+This project was inspired by
+[this article](https://dev.to/danielelkington/a-bot-that-tweets-new-dev-articles-about-vue-4p5a).
+
+This function depends on a few environment variables:
+
+- `dev_tag`: the dev.to tag to which the crawler will get the latest articles.
+- `twitter_bot_screen_name`: the name of the account that will tweet the
+  articles.
+- Twitter keys:
+  - `twitter_consumer_key`
+  - `twitter_consumer_secret`
+  - `twitter_access_token`
+  - `twitter_access_token_secret`
+- `telegram_bot_token`: the telegram bot who's going to log messages for
+  maintenance/debug purposes
+- `telegram_chat_id`: the channel where the bot will send messages
+
+You just need to create a `env.yml` file and put those values in, like this:
+
+```yml
+dev_tag: "react"
+twitter_bot_screen_name: "NameOfTheTwitterAccount"
+twitter_consumer_key: "..."
+twitter_consumer_secret: "..."
+twitter_access_token: "..."
+twitter_access_token_secret: "..."
+telegram_bot_token: "..."
+telegram_chat_id: "..."
+```
+
+It's worth noting that I used telegram here because it was simple and it
+probably is the fastest way I can see a message in case things go wrong.
+Probably sentry.io would be more
+
+I started using azure, like
+[twitter-vue-dev](http://github.com/danielelkington/twitter-vue-dev/), but after
+a few hours of headaches I'm switching to the serverless framework with aws.

getLatestArticles.js

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+const Xray = require("x-ray")
+const URL = require("url").URL
+
+const X = Xray({
+  filters: {
+    trim: value => value.trim(),
+    parseName: value => value.split("・")[0]
+  }
+})
+
+module.exports = async tag => {
+  const articles = await X(
+    `https://dev.to/t/${tag}/latest`,
+    "#substories .single-article",
+    [
+      {
+        title: ".index-article-link .content h3 | trim",
+        link: ".index-article-link@href",
+        tags: [".tags .tag"],
+        author: {
+          name: "h4 a | parseName",
+          link: ".small-pic-link-wrapper@href"
+        }
+      }
+    ]
+  ).then(articles => articles.filter(article => article.title))
+
+  // get twitter handle
+  for (article of articles) {
+    const socialLinks = await X(article.author.link, [
+      ".profile-details .social a@href"
+    ])
+    const twitter = socialLinks.find(url => url.includes("twitter.com/"))
+    if (twitter) {
+      const twitterURL = new URL(twitter)
+      article.author.twitterHandle = `@${twitterURL.pathname.substring(1)}`
+    }
+  }
+
+  return articles
+}

handler.js

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+"use strict"
+
+const axios = require("axios")
+
+const getLatestDevArticles = require("./getLatestArticles")
+const { getRecentTweets, tweet, isPublished, format } = require("./twitter")
+
+const sendToTelegram = async text =>
+  axios.post(
+    `https://api.telegram.org/bot${process.env.telegram_bot_token}/sendMessage`,
+    { chat_id: process.env.telegram_chat_id, text }
+  )
+
+module.exports.scrapArticlesAndTweet = async () => {
+  const articles = await getLatestDevArticles(process.env.dev_tag)
+  const recentTweets = await getRecentTweets(
+    process.env.twitter_bot_screen_name
+  )
+
+  for (article of articles) {
+    if (!isPublished(article, recentTweets)) {
+      const data = await tweet(format(article))
+      const log = `Tweeted ${article.title} on ${
+        data.id
+      } at ${new Date().toISOString()}`
+      sendToTelegram(log)
+    }
+  }
+}

package.json

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+{
+  "dependencies": {
+    "axios": "^0.18.0",
+    "twit": "^2.2.11",
+    "x-ray": "^2.3.3"
+  }
+}

serverless.yml

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+service: TheReactDev
+
+provider:
+  name: aws
+  runtime: nodejs8.10
+  environment: ${file(env.yml)}
+
+functions:
+  scrapArticlesAndTweet:
+    handler: handler.scrapArticlesAndTweet
+    events:
+      - schedule: rate(2 minutes)

twitter.js

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+const Twit = require("twit")
+const T = Twit({
+  consumer_key: process.env.twitter_consumer_key,
+  consumer_secret: process.env.twitter_consumer_secret,
+  access_token: process.env.twitter_access_token,
+  access_token_secret: process.env.twitter_access_token_secret
+})
+
+module.exports = {
+  getRecentTweets: async () =>
+    T.get("statuses/user_timeline", {
+      screen_name: process.env.twitter_bot_screen_name,
+      trim_user: true,
+      tweet_mode: "extended"
+    }).then(res => res.data),
+  tweet: async status => T.post("statuses/update", { status }),
+  isPublished: (article, tweets) => {
+    const tweet = tweets
+      .map(tweet => tweet.entities.urls[0])
+      .find(entity => entity.expanded_url === article.link)
+    return !!tweet
+  },
+  format: article =>
+    `"${article.title}" by ${article.author.twitterHandle ||
+      article.author.name}\n#DEVcommunity ${article.tags.join(" ")}\n${
+      article.link
+    }`
+}