Send a path, not full url, to trackers for pageviews

CHANGELOG.md

@@ -1,3 +1,7 @@
+# Unreleased
+
+- Use a path, not a full url, as the `defaultPathForTrackPageview` because our analytics trackers expect the explicit page param to be a path, not a url ([PR #451](https://github.com/alphagov/govuk_frontend_toolkit/pull/451)).  Analytics sent with 7.3.0 and 7.4.0 are broken without this fix.
+
 # 7.4.0
 
 - Allow wrapping arguments to analytics as PII safe to tell the analytics code not to attempt to strip PII from the values: ([PR #448](https://github.com/alphagov/govuk_frontend_toolkit/pull/448))

javascripts/govuk/analytics/analytics.js

@@ -93,17 +93,17 @@
     GOVUK.GOVUKTracker.load()
   }
 
-  Analytics.prototype.defaultPathForTrackPageview = function () {
-    // Ignore anchor, but keep query string as per default behaviour of
-    // GA (see: https://developers.google.com/analytics/devguides/collection/analyticsjs/pages#overview)
+  Analytics.prototype.defaultPathForTrackPageview = function (location) {
+    // Get the page path including querystring, but ignoring the anchor
+    // as per default behaviour of GA (see: https://developers.google.com/analytics/devguides/collection/analyticsjs/pages#overview)
     // we ignore the possibility of there being campaign variables in the
     // anchor because we wouldn't know how to detect and parse them if they
     // were present
-    return this.stripPIIFromString(window.location.href.split('#')[0])
+    return this.stripPIIFromString(location.href.substring(location.origin.length).split('#')[0])
   }
 
   Analytics.prototype.trackPageview = function (path, title, options) {
-    arguments[0] = arguments[0] || this.defaultPathForTrackPageview()
+    arguments[0] = arguments[0] || this.defaultPathForTrackPageview(window.location)
     if (arguments.length === 0) { arguments.length = 1 }
     this.sendToTrackers('trackPageview', this.stripPII(arguments))
   }

spec/unit/analytics/analytics.spec.js

@@ -49,25 +49,53 @@ describe('GOVUK.Analytics', function () {
     })
   })
 
+  describe('extracting the default path for a page view', function () {
+    it('returns a path extracted from the location', function () {
+      var location = {
+        href: 'https://govuk-frontend-toolkit.example.com/a/path',
+        origin: 'https://govuk-frontend-toolkit.example.com'
+      }
+      expect(analytics.defaultPathForTrackPageview(location)).toEqual('/a/path')
+    })
+
+    it('includes the querystring in the path extracted from the location', function () {
+      var location = {
+        href: 'https://govuk-frontend-toolkit.example.com/a/path?with=a&query=string',
+        origin: 'https://govuk-frontend-toolkit.example.com'
+      }
+      expect(analytics.defaultPathForTrackPageview(location)).toEqual('/a/path?with=a&query=string')
+    })
+
+    it('removes any anchor from the path extracted from the location', function () {
+      var location = {
+        href: 'https://govuk-frontend-toolkit.example.com/a/path#with-an-anchor',
+        origin: 'https://govuk-frontend-toolkit.example.com'
+      }
+      expect(analytics.defaultPathForTrackPageview(location)).toEqual('/a/path')
+      location.href = 'https://govuk-frontend-toolkit.example.com/a/path?with=a&query=string#with-an-anchor'
+      expect(analytics.defaultPathForTrackPageview(location)).toEqual('/a/path?with=a&query=string')
+    })
+  })
+
   describe('tracking pageviews', function () {
     beforeEach(function () {
-      spyOn(analytics, 'defaultPathForTrackPageview').and.returnValue('https://govuk-frontend-toolkit.example.com/a/page?with=a&query=string')
+      spyOn(analytics, 'defaultPathForTrackPageview').and.returnValue('/a/page?with=a&query=string')
     })
 
     it('injects a default path if no args are supplied', function () {
       analytics.trackPageview()
       console.log(window.ga.calls.mostRecent().args)
-      expect(window.ga.calls.mostRecent().args[2].page).toEqual('https://govuk-frontend-toolkit.example.com/a/page?with=a&query=string')
+      expect(window.ga.calls.mostRecent().args[2].page).toEqual('/a/page?with=a&query=string')
     })
 
     it('injects a default path if args are supplied, but the path arg is blank', function () {
       analytics.trackPageview(null)
       console.log(window.ga.calls.mostRecent().args)
-      expect(window.ga.calls.mostRecent().args[2].page).toEqual('https://govuk-frontend-toolkit.example.com/a/page?with=a&query=string')
+      expect(window.ga.calls.mostRecent().args[2].page).toEqual('/a/page?with=a&query=string')
 
       analytics.trackPageview(undefined)
       console.log(window.ga.calls.mostRecent().args)
-      expect(window.ga.calls.mostRecent().args[2].page).toEqual('https://govuk-frontend-toolkit.example.com/a/page?with=a&query=string')
+      expect(window.ga.calls.mostRecent().args[2].page).toEqual('/a/page?with=a&query=string')
     })
 
     it('uses the supplied path', function () {