complete performance and reliability follow-ups

packages/uploader/src/runtime.ts

@@ -170,7 +170,8 @@ export const UPLOAD_RUNTIME = `
       });
       xhr.addEventListener("load", function () {
         var data = null;
-        try { data = JSON.parse(xhr.responseText); } catch (e2) {}
+        try { data = JSON.parse(xhr.responseText); }
+        catch (error) { console.warn("[wrnexus:uploader] upload response was not valid JSON", error); }
         if (xhr.status >= 200 && xhr.status < 300 && data && data.ok) {
           done(ui, (data.files && data.files[0]) || null, file);
         } else {

packages/uploader/test/uploader.test.ts

@@ -11,6 +11,12 @@ import {
   upload,
   verifySignedFileToken,
 } from "../src/index.ts";
+import { UPLOAD_RUNTIME } from "../src/runtime.ts";
+
+test("browser upload response parse failures emit a diagnostic", () => {
+  expect(UPLOAD_RUNTIME).toContain("upload response was not valid JSON");
+  expect(UPLOAD_RUNTIME).not.toContain("catch (e2) {}");
+});
 
 function configure() {
   configureStorage(