first commit

dash/docs/screenshotter/screenshot.js

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+const puppeteer = require("puppeteer");
+const fs = require("fs");
+const PNG = require("pngjs").PNG;
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+const URL = process.env.URL || "CHANGEME";
+
+(async () => {
+  const browser = await puppeteer.launch({
+    args: ["--no-sandbox", "--disable-setuid-sandbox"],
+  });
+
+  const page = await browser.newPage();
+
+  /* Kindle 4 NT resolution */
+  await page.setViewport({ width: 600, height: 800 });
+
+  /* Might want to use networkidle0 here, depending on the type of page */
+  /* See https://github.com/puppeteer/puppeteer/blob/main/docs/api.md */
+  await page.goto(URL, { waitUntil: "networkidle2" });
+
+  /* This is a bit silly. ¯\_(ツ)_/¯
+  Networkidle2 doesn't always seem to wait long enough. */
+  await sleep(3000);
+
+  await page.screenshot({ path: "dash.png" });
+
+  await fs.createReadStream("dash.png")
+    .pipe(new PNG({ colorType: 0 }))
+    .on("parsed", function () {
+      this.pack().pipe(fs.createWriteStream("dash.png"));
+    });
+
+  browser.close();
+})();