add test harness (from #97)

Author: emma-sg

scripts/test-harness.mjs

@@ -0,0 +1,72 @@
+import puppeteer from "puppeteer";
+import Webpack from "webpack";
+import { fs } from "memfs";
+
+import webpackConfig from "../webpack.config.js";
+
+/**
+ * Validate a URL
+ * @param {URL} url
+ * @returns {boolean}
+ */
+const validateUrl = (url) => {
+  try {
+    return new URL(url);
+  } catch (_e) {
+    return false;
+  }
+};
+
+if (!process.argv[2]) {
+  console.error("Usage: yarn test '<url>'");
+  process.exit(1);
+}
+
+if (!validateUrl(process.argv[2])) {
+  console.error("Invalid URL (hint: include http:// or https://)");
+  process.exit(1);
+}
+
+const config = webpackConfig({}, { mode: "development" });
+
+const compiler = Webpack(config);
+compiler.outputFileSystem = fs;
+
+const browser = await puppeteer.launch({ headless: false, devtools: true });
+const page = await browser.newPage();
+
+const _watching = compiler.watch({}, async (err, stats) => {
+  if (err) {
+    console.error(err);
+    console.error("Not opening browser");
+    return;
+  }
+  console.log(
+    stats.toString({
+      colors: true,
+      preset: "summary",
+    }),
+  );
+  const behaviorScript = fs.readFileSync("dist/behaviors.js", "utf8");
+
+  await page.goto(validateUrl(process.argv[2]));
+
+  await page.evaluate(
+    behaviorScript +
+      `
+  self.__bx_behaviors.init({
+    autofetch: true,
+    autoplay: true,
+    autoscroll: true,
+    siteSpecific: true,
+  });
+  `,
+  );
+
+  // call and await run on top frame and all child iframes
+  await Promise.allSettled(
+    page
+      .frames()
+      .map(async (frame) => frame.evaluate("self.__bx_behaviors.run()")),
+  );
+});