chore: first commit

.gitignore

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+node_modules/

index.js

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+import {
+  fetchResponseAsText,
+  getStaticScriptsUrl,
+  getEnvFromBundles,
+} from "./utils.js";
+
+const [, , url] = process.argv;
+
+export default async function main() {
+  const markupText = await fetchResponseAsText(url);
+  const staticScriptsUrl = getStaticScriptsUrl(markupText, url);
+  const result = await getEnvFromBundles(staticScriptsUrl);
+  console.log(result);
+}
+
+(async () => main())();

package.json

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+{
+  "name": "get-react-envs",
+  "version": "0.0.1",
+  "description": "",
+  "type": "module",
+  "main": "index.js",
+  "scripts": {},
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "cheerio": "^1.0.0-rc.12",
+    "node-fetch": "^3.2.10"
+  }
+}

utils.js

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+import fetch from "node-fetch";
+import { load } from "cheerio";
+
+/**
+ * Fetchs text response for a url
+ *
+ * @param {String} url Url to be fetched
+ * @returns {Promise<String>} Text Response
+ */
+export async function fetchResponseAsText(url) {
+  const response = await fetch(url);
+  const text = await response.text();
+  return text;
+}
+
+/**
+ * Gets an array of all static script urls
+ *
+ * @param {String} markup MarkupString
+ * @returns {Array<string>} Array of static script urls
+ */
+export function getStaticScriptsUrl(markup, url) {
+  const $ = load(markup);
+  const bundleUrls = $("script")
+    .map((_, el) => {
+      if (!el.attribs.src) return undefined;
+      const _url = url.endsWith("/") ? url.slice(0, url.length - 1) : url;
+      const _src = el.attribs.src.startsWith(".")
+        ? el.attribs.src.slice(1)
+        : el.attribs.src;
+      return _src.startsWith("http") ? _src : _url + _src;
+    })
+    .filter(Boolean)
+    .toArray();
+  return bundleUrls;
+}
+
+/**
+ * Searches for React environment variables and
+ * returns array of env. objects
+ *
+ * @param {Array<string>} urls Script Urls
+ * @returns {Promise<Array<Record<string, string>>>} Array of founded enviroment objects
+ */
+export async function getEnvFromBundles(urls) {
+  const results = await Promise.all(
+    urls.map(async (url) => {
+      const jsText = await fetchResponseAsText(url);
+      const envs = jsText.match(/REACT_APP[\w]+:[\S]+?('|"|$)/g);
+      if (envs) {
+        const data = envs
+          .map((envStr) => envStr.split(/:(.*)/s).slice(0, 2))
+          .map(([k, v]) => [k, v.replace(/"/g, "")]);
+        return Object.fromEntries(data);
+      }
+    })
+  );
+  return results.filter(Boolean);
+}