Prevent GA4 data sending during Smokey tests

This prevents the GA4 dashboards being polluted with Smokey test data

CHANGELOG.md

@@ -10,6 +10,7 @@
 ## Unreleased
 
 * Add metadata inverse no padding option ([PR #3689](/~https://github.com/alphagov/govuk_publishing_components/pull/3689))
+* Prevent GA4 data sending during Smokey tests ([PR #3680](/~https://github.com/alphagov/govuk_publishing_components/pull/3680))
 
 ## 35.20.1
 

app/assets/javascripts/govuk_publishing_components/analytics-ga4/ga4-core.js

@@ -30,7 +30,16 @@ window.GOVUK.analyticsGa4 = window.GOVUK.analyticsGa4 || {};
       firstScript.parentNode.insertBefore(newScript, firstScript)
     },
 
+    getUserAgent: function () {
+      return navigator.userAgent
+    },
+
     sendData: function (data) {
+      // Prevent any GA4 data being sent during Smokey tests
+      if (this.getUserAgent() === 'Smokey Test / Ruby') {
+        return
+      }
+
       data.govuk_gem_version = this.getGemVersion()
       // set this in the console as a debugging aid
       if (window.GOVUK.analyticsGa4.showDebug) {

spec/javascripts/govuk_publishing_components/analytics-ga4/ga4-core.spec.js

@@ -68,6 +68,15 @@ describe('GA4 core', function () {
     })
   })
 
+  it('does not push data to the dataLayer if it is a Smokey test', function () {
+    spyOn(GOVUK.analyticsGa4.core, 'getUserAgent').and.returnValue('Smokey Test / Ruby')
+    var data = {
+      hello: 'I must be going'
+    }
+    GOVUK.analyticsGa4.core.sendData(data)
+    expect(window.dataLayer).toEqual([])
+  })
+
   describe('link tracking functions', function () {
     describe('find tracking attributes on elements', function () {
       var element