Track the Continuous Onboarding Iteration 2 experiment

- Create a custom experiment class so we can add the project's
  namespace's id to the automatically tracked "assignment" event
- Add data-track-experiment attribute to the Learn GitLab dashboard
  links

app/assets/javascripts/pages/projects/learn_gitlab/components/learn_gitlab_section_link.vue

@@ -40,6 +40,7 @@ export default {
         data-track-action="click_link"
         :data-track-label="$options.i18n.ACTION_LABELS[action].title"
         data-track-property="Growth::Conversion::Experiment::LearnGitLab"
+        data-track-experiment="change_continuous_onboarding_link_urls"
       >
         {{ $options.i18n.ACTION_LABELS[action].title }}
       </gl-link>

app/experiments/change_continuous_onboarding_link_urls_experiment.rb

+# frozen_string_literal: true
+
+class ChangeContinuousOnboardingLinkUrlsExperiment < ApplicationExperiment # rubocop:disable Gitlab/NamespacedClass
+  attr_writer :namespace
+
+  def track(action, **event_args)
+    super(action, **event_args.merge(namespace: @namespace))
+  end
+end

app/helpers/learn_gitlab_helper.rb

@@ -13,6 +13,7 @@ module LearnGitlabHelper
     urls_to_use = nil
 
     experiment(:change_continuous_onboarding_link_urls) do |e|
+      e.namespace = project.namespace
       e.use { urls_to_use = action_urls }
       e.try { urls_to_use = new_action_urls(project) }
     end

spec/experiments/change_continuous_onboarding_link_urls_experiment_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ChangeContinuousOnboardingLinkUrlsExperiment, :snowplow do
+  before do
+    stub_experiments(change_continuous_onboarding_link_urls: 'control')
+  end
+
+  describe '#track' do
+    context 'when no namespace has been set' do
+      it 'tracks the action as normal' do
+        subject.track(:some_action)
+
+        expect_snowplow_event(
+          category: subject.name,
+          action: 'some_action',
+          namespace: nil,
+          context: [
+            {
+              schema: 'iglu:com.gitlab/gitlab_experiment/jsonschema/1-0-0',
+              data: an_instance_of(Hash)
+            }
+          ]
+        )
+      end
+    end
+
+    context 'when a namespace has been set' do
+      let_it_be(:namespace) { create(:namespace) }
+
+      before do
+        subject.namespace = namespace
+      end
+
+      it 'tracks the action and merges the namespace into the event args' do
+        subject.track(:some_action)
+
+        expect_snowplow_event(
+          category: subject.name,
+          action: 'some_action',
+          namespace: namespace,
+          context: [
+            {
+              schema: 'iglu:com.gitlab/gitlab_experiment/jsonschema/1-0-0',
+              data: an_instance_of(Hash)
+            }
+          ]
+        )
+      end
+    end
+  end
+end

spec/frontend/pages/projects/learn_gitlab/components/__snapshots__/learn_gitlab_spec.js.snap

@@ -135,6 +135,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Set up CI/CD"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -156,6 +157,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Start a free Ultimate trial"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -177,6 +179,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Add code owners"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -205,6 +208,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Add merge request approval"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -269,6 +273,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Create an issue"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -290,6 +295,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Submit a merge request"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"
@@ -347,6 +353,7 @@ exports[`Learn GitLab renders correctly 1`] = `
               <a
                 class="gl-link"
                 data-track-action="click_link"
+                data-track-experiment="change_continuous_onboarding_link_urls"
                 data-track-label="Run a Security scan using CI/CD"
                 data-track-property="Growth::Conversion::Experiment::LearnGitLab"
                 href="http://example.com/"