🐛 Force @percy/dom globalization (#237)

* 🐛 Force @percy/dom globalization

Sometimes modules or exports are polyfilled causing the UMD bundle to not attach the DOM script to
the global scope. Since this scope issue seems to keep coming up, let's always set the serialize
function globally when the window object is defined.

* ♻ Type check gobalThis rather than try-catch usage

packages/dom/src/index.js

@@ -1,14 +1,9 @@
 import serialize from './serialize-dom';
 
 /* istanbul ignore next */
-// works around instances where the context has an incorrect global scope
-// https://github.com/mozilla/geckodriver/issues/1798
-try {
-  if (globalThis !== window) {
-    window.PercyDOM = { serialize };
-  }
-} catch (error) {
-  // `globalThis` is probably not defined
+// works around instances where the context has an incorrect scope
+if (typeof window !== 'undefined') {
+  window.PercyDOM = exports;
 }
 
 export { serialize };

rollup.config.js

@@ -45,8 +45,7 @@ const base = {
     ...pkg.rollup.output,
     intro: [
       // provide the bundle with a fake process.env if needed
-      'let process = {};',
-      'try { process = globalThis.process || {}; } catch (e) {}',
+      'const process = (typeof globalThis !== "undefined" && globalThis.process) || {};',
       'process.env = process.env || {};',
       // signals that the package is running in a browserified bundle
       'process.env.__PERCY_BROWSERIFIED__ = true;'