Slack members scrapper

slack-members-scrapper.js

/**
 * Slack members scrapper.
 *
 * Downloads a .csv file with members details.
 *
 * 1. Open /people on slack webapp: https://app.slack.com/client/<WORKSPACE_ID>/people
 * 2. Paste it into the console
 */
(() => {
  class CSVTransformer {
    #columns = [];

    /**
     * @description Creates a new CSV transformer.
     * @param {DataEntry[]} data An array of entries to include in the CSV file.
     */
    constructor(data) {
      this.data = data;
    }

    /**
     * @description Add a new column that will be respected with the `build` method.
     * @param {string} label A column title.
     * @param {(item: DataEntry) => void} transformer Extract column data from the `data` entry.
     * @returns `CSVTransformer`
     */
    withColumn(label, transformer) {
      this.#columns.push({ label, transformer });

      return this;
    }

    /**
     * @description Build raw string of CSV formatted `data`.
     * @returns string
     */
    build(delimiter = ";") {
      const header = `${this.#columns.map(({ name }) => name).join(delimiter)}`;
      const rows = this.data.map((item) =>
        this.#columns
          .map(({ transformer }) => transformer(item))
          .join(delimiter)
      );

      return [header, ...rows].join(`\n`);
    }
  }

  class SlackScrapper {
    #selectors = {
      memberCard: {
        default: '[data-qa="browse_page_member"]',
        image: "img",
        name: '[data-qa="browse_page_member_card_entity__name_text"]',
      },
    };

    getAllMembers() {
      return [
        ...document.querySelectorAll(this.#selectors.memberCard.default),
      ].map((card) => {
        const imageUrl = card.querySelector(
          this.#selectors.memberCard.image
        ).src;
        const name = card.querySelector(
          this.#selectors.memberCard.name
        ).innerHTML;
        return { imageUrl, name };
      });
    }
  }

  function downloadAsFile(fileContent, fileName, fileExtension) {
    const hiddenElement = document.createElement("a");
    hiddenElement.href = "data:attachment/text," + encodeURI(fileContent);
    hiddenElement.target = "_blank";
    hiddenElement.download = `${fileName}.${fileExtension}`;
    hiddenElement.click();
  }

  function run() {
    const slackScrapper = new SlackScrapper();

    const members = slackScrapper.getAllMembers();
    const csvContent = new CSVTransformer(members)
      .withColumn("IMAGE_URL", (item) => item.imageUrl)
      .withColumn("NAME", (item) => item.name)
      .build();

    downloadAsFile(csvContent, "slack-members", "csv");
  }

  run();
})();