Adding blocking hosts example (#120)

* Update README.md

* Create BlockHosts.md

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* Update BlockHosts.md

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docs/README.md

@@ -56,3 +56,4 @@ For now, the examples exist in markdown files that you can read and copy into yo
 - [SSO Redirects and Basic Auth](examples/HandleSSORedirectAndBasicAuth.md) -
 - [Log Into Drupal and Create a Node](examples/LogIntoDrupalAndCreateANode.md) -
 - [Lighthouse Audits](examples/LighthouseAudits.md) -
+- [Block Hosts](examples/BlockHosts.md) -

docs/examples/BlockHosts.md

@@ -0,0 +1,43 @@
+# Blocking Hosts in Tests
+
+The most common host you want to block in the tests in Google Analytics. To do that use the [`blockHosts`](https://docs.cypress.io/app/references/configuration#blockHosts) configuration option. Here is an example of a list of hosts we block including Google Analytics:
+
+```javascript
+  blockHosts: [
+    '*doubleclick.net',
+    '*google-analytics.com',
+    '*tealiumiq.com',
+    '*quantummetric.com',
+    'g*qualtrics.com',
+    '*nr-data.net',
+    '*youtube.com',
+    '*tiqcdn.com',
+    '*touchpoints.app.cloud.gov',
+    '*script.crazyegg.com',
+    '*googletagmanager.com',
+    '*googleapis.com'
+  ],
+```
+
+While the hosts are blocked you still might see fetch/xhr requests in the Cypress logs/screenshots/videos. To hide those add the following to the `cypress/support/e2e.js` file:
+
+```javascript
+// Hide fetch/XHR requests
+const cypressLogOriginal = Cypress.log
+const cypressLogDomainsHidden = ['https://www.google-analytics.com']
+Cypress.log = function (opts, ...other) {
+  const logFetchIs = ['fetch'].includes(opts.displayName)
+  const logFetchDomainMatch =
+    logFetchIs && cypressLogDomainsHidden.find((d) => opts.url.includes(d))
+  if (logFetchDomainMatch) return
+
+  return cypressLogOriginal(opts, ...other)
+}
+```
+
+[Credit for the code snippet](https://gist.github.com/simenbrekken/3d2248f9e50c1143bf9dbe02e67f5399?permalink_comment_id=4190114#gistcomment-4190114).
+
+## Useful references
+
+- https://docs.cypress.io/app/references/configuration#blockHosts
+- https://gist.github.com/simenbrekken/3d2248f9e50c1143bf9dbe02e67f5399?permalink_comment_id=4190114#gistcomment-4190114