Block Google telemetry in browser tests

Earlier Puppeteer/Chromium versions weren't phoning home to Google, but this
appears to have changed after #145. This updates are proxy configuration to
return 403s for any Google URLs which keeps them out of the test fixtures and
makes things more predictable. A browser test has been added which verifies
this behavior.

Connects #145

Merges #150

LGTM given by: @KPreisner

test/browser.test.ts

@@ -29,6 +29,31 @@ test("library is injected and authorized", async (t) => {
   t.truthy(baseUrl);
 });
 
+test("access to google.com is blocked", async (t) => {
+  // Squash Chrome's error logging for this page, we expect a 403 error.
+  t.context.page.removeAllListeners("console");
+  const status: number | null = await t.context.page.evaluate(async () => {
+    // Hackily use the sindri's internal client to make a request to Google.
+    sindri._clientConfig.BASE = "https://accounts.google.com";
+    try {
+      const response: { status: number } = await sindri._client.request.request(
+        {
+          method: "GET",
+          url: "/ListAccounts",
+        },
+      );
+      return response?.status ?? null;
+    } catch (error) {
+      return (error as { status: number })?.status ?? null;
+    }
+  });
+  t.deepEqual(
+    status,
+    403,
+    "Requests to google.com delays should be blocked with a 403 status code.",
+  );
+});
+
 test("create circuit from file array", async (t) => {
   const circuitDirectory = path.join(dataDirectory, "circom-multiplier2");
   const fileNames = await fs.readdir(circuitDirectory);

test/utils/usePage.ts

@@ -32,6 +32,21 @@ function createProxy(): Proxy {
   const proxy = new Proxy();
   proxy.use(Proxy.wildcard);
 
+  // Block Google phoning home.
+  proxy.onRequest((ctx, callback) => {
+    const host = ctx.clientToProxyRequest.headers.host ?? "";
+    if (/(^|.).google.com/i.test(host)) {
+      // Return 403 errors for any Google requests.
+      ctx.proxyToClientResponse.writeHead(403, {
+        "Content-Type": "text/plain",
+      });
+      ctx.proxyToClientResponse.end("Bad Request: Google Services Blocked");
+    } else {
+      // Continue processing the request normally if it's not Google.
+      return callback();
+    }
+  });
+
   // The library uses `console.debug()` a lot and it's noisy.
   console.debug = () => {};