Implement experiment for new create project

Add Vue-based experiment for new create project UX

app/assets/javascripts/pages/projects/new/index.js

 import initProjectVisibilitySelector from '../../../project_visibility';
 import initProjectNew from '../../../projects/project_new';
+import { __ } from '~/locale';
+import createFlash from '~/flash';
+import Tracking from '~/tracking';
 
 document.addEventListener('DOMContentLoaded', () => {
   initProjectVisibilitySelector();
   initProjectNew.bindEvents();
+
+  const { category, property } = gon.tracking_data ?? { category: 'projects:new' };
+  const hasNewCreateProjectUi = 'newCreateProjectUi' in gon?.features;
+
+  if (!hasNewCreateProjectUi) {
+    // Setting additional tracking for HAML template
+
+    Array.from(
+      document.querySelectorAll('.project-edit-container [data-experiment-track-label]'),
+    ).forEach(node =>
+      node.addEventListener('click', event => {
+        const { experimentTrackLabel: label } = event.currentTarget.dataset;
+        Tracking.event(category, 'click_tab', { property, label });
+      }),
+    );
+  } else {
+    import(
+      /* webpackChunkName: 'experiment_new_project_creation' */ '../../../projects/experiment_new_project_creation'
+    )
+      .then(m => {
+        const el = document.querySelector('.js-experiment-new-project-creation');
+
+        if (!el) {
+          return;
+        }
+
+        const config = {
+          hasErrors: 'hasErrors' in el.dataset,
+          isCiCdAvailable: 'isCiCdAvailable' in el.dataset,
+        };
+        m.default(el, config);
+      })
+      .catch(() => {
+        createFlash(__('An error occurred while loading project creation UI'));
+      });
+  }
 });

app/assets/javascripts/projects/experiment_new_project_creation/components/app.vue

+<script>
+import WelcomePage from './welcome.vue';
+import LegacyContainer from './legacy_container.vue';
+import { GlBreadcrumb, GlIcon } from '@gitlab/ui';
+import { __, s__ } from '~/locale';
+
+import blankProjectIllustration from '../illustrations/blank-project.svg';
+import createFromTemplateIllustration from '../illustrations/create-from-template.svg';
+import importProjectIllustration from '../illustrations/import-project.svg';
+import ciCdProjectIllustration from '../illustrations/ci-cd-project.svg';
+
+const BLANK_PANEL = 'blank_project';
+const CI_CD_PANEL = 'cicd_for_external_repo';
+const PANELS = [
+  {
+    name: BLANK_PANEL,
+    selector: '#blank-project-pane',
+    title: s__('ProjectsNew|Create blank project'),
+    description: s__(
+      'ProjectsNew|Create a blank project to house your files, plan your work, and collaborate on code, among other things.',
+    ),
+    illustration: blankProjectIllustration,
+  },
+  {
+    name: 'create_from_template',
+    selector: '#create-from-template-pane',
+    title: s__('ProjectsNew|Create from template'),
+    description: s__(
+      'Create a project pre-populated with the necessary files to get you started quickly.',
+    ),
+    illustration: createFromTemplateIllustration,
+  },
+  {
+    name: 'import_project',
+    selector: '#import-project-pane',
+    title: s__('ProjectsNew|Import project'),
+    description: s__(
+      'Migrate your data from an external source like GitHub, Bitbucket, or another instance of GitLab.',
+    ),
+    illustration: importProjectIllustration,
+  },
+  {
+    name: CI_CD_PANEL,
+    selector: '#ci-cd-project-pane',
+    title: s__('ProjectsNew|Run CI/CD for external repository'),
+    description: s__('ProjectsNew|Connect your external repository to GitLab CI/CD.'),
+    illustration: ciCdProjectIllustration,
+  },
+];
+
+export default {
+  components: {
+    GlBreadcrumb,
+    GlIcon,
+    WelcomePage,
+    LegacyContainer,
+  },
+
+  props: {
+    hasErrors: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    isCiCdAvailable: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+
+  data() {
+    return {
+      activeTab: null,
+    };
+  },
+
+  computed: {
+    availablePanels() {
+      if (this.isCiCdAvailable) {
+        return PANELS;
+      }
+
+      return PANELS.filter(p => p.name !== CI_CD_PANEL);
+    },
+
+    activePanel() {
+      return PANELS.find(p => p.name === this.activeTab);
+    },
+
+    breadcrumbs() {
+      if (!this.activeTab || !this.activePanel) {
+        return null;
+      }
+
+      return [
+        { text: __('New project'), href: '#' },
+        { text: this.activePanel.title, href: `#${this.activeTab}` },
+      ];
+    },
+  },
+
+  created() {
+    this.handleLocationHashChange();
+
+    if (this.hasErrors) {
+      this.activeTab = BLANK_PANEL;
+    }
+
+    window.addEventListener('hashchange', () => {
+      this.handleLocationHashChange();
+      this.resetProjectErrors();
+    });
+    this.$root.$on('clicked::link', e => {
+      window.location = e.target.href;
+    });
+  },
+
+  methods: {
+    resetProjectErrors() {
+      const errorsContainer = document.querySelector('.project-edit-errors');
+      if (errorsContainer) {
+        errorsContainer.innerHTML = '';
+      }
+    },
+
+    handleLocationHashChange() {
+      this.activeTab = window.location.hash.substring(1) || null;
+    },
+  },
+
+  PANELS,
+};
+</script>
+
+<template>
+  <welcome-page v-if="activeTab === null" :panels="availablePanels" />
+  <div v-else class="row">
+    <div class="col-lg-3">
+      <div class="text-center" v-html="activePanel.illustration"></div>
+      <h4>{{ activePanel.title }}</h4>
+      <p>{{ activePanel.description }}</p>
+    </div>
+    <div class="col-lg-9">
+      <gl-breadcrumb v-if="breadcrumbs" :items="breadcrumbs">
+        <template #separator>
+          <gl-icon name="chevron-right" :size="8" />
+        </template>
+      </gl-breadcrumb>
+      <template v-for="panel in $options.PANELS">
+        <legacy-container
+          v-if="activeTab === panel.name"
+          :key="panel.name"
+          class="gl-mt-3"
+          :selector="panel.selector"
+        />
+      </template>
+    </div>
+  </div>
+</template>

app/assets/javascripts/projects/experiment_new_project_creation/components/legacy_container.vue

+<script>
+export default {
+  inheritAttrs: false,
+  props: {
+    selector: {
+      type: String,
+      required: true,
+    },
+  },
+  mounted() {
+    const legacyEntry = document.querySelector(this.selector);
+    if (legacyEntry.tagName === 'TEMPLATE') {
+      this.$el.innerHTML = legacyEntry.innerHTML;
+    } else {
+      this.source = legacyEntry.parentNode;
+      this.$el.appendChild(legacyEntry);
+    }
+  },
+
+  beforeDestroy() {
+    if (this.source) {
+      this.source.appendChild(this.$el.firstChild);
+    }
+  },
+};
+</script>
+<template>
+  <div></div>
+</template>

app/assets/javascripts/projects/experiment_new_project_creation/components/welcome.vue

+<script>
+import Tracking from '~/tracking';
+import { GlPopover } from '@gitlab/ui';
+import LegacyContainer from './legacy_container.vue';
+
+const trackingMixin = Tracking.mixin(gon.tracking_data);
+
+export default {
+  components: {
+    GlPopover,
+    LegacyContainer,
+  },
+  mixins: [trackingMixin],
+  props: {
+    panels: {
+      type: Array,
+      required: true,
+    },
+  },
+};
+</script>
+<template>
+  <div class="container">
+    <div class="blank-state-welcome">
+      <h2 class="blank-state-welcome-title gl-mt-5! gl-mb-3!">
+        {{ s__('ProjectsNew|Create new project') }}
+      </h2>
+      <p div class="blank-state-text">&nbsp;</p>
+    </div>
+    <div class="row blank-state-row">
+      <a
+        v-for="panel in panels"
+        :key="panel.name"
+        :href="`#${panel.name}`"
+        class="blank-state blank-state-link experiment-new-project-page-blank-state"
+        @click="track('click_tab', { label: panel.name })"
+      >
+        <div class="blank-state-icon" v-html="panel.illustration"></div>
+        <div class="blank-state-body gl-pl-4!">
+          <h3 class="blank-state-title experiment-new-project-page-blank-state-title">
+            {{ panel.title }}
+          </h3>
+          <p class="blank-state-text">
+            {{ panel.description }}
+          </p>
+        </div>
+      </a>
+    </div>
+    <div class="blank-state-welcome">
+      <p>
+        {{ __('You can also create a project from the command line.') }}
+        <a
+          id="cli-tip"
+          href="#"
+          click.prevent
+          class="push-new-project-tip"
+          data-title="Push to create a project"
+          rel="noopener noreferrer"
+        >
+          {{ __('Show command') }}
+        </a>
+
+        <gl-popover target="cli-tip" triggers="click blur" placement="top">
+          <legacy-container selector=".push-new-project-tip-template" />
+        </gl-popover>
+      </p>
+    </div>
+  </div>
+</template>

app/assets/javascripts/projects/experiment_new_project_creation/illustrations/blank-project.svg

+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="215px" height="115px" viewBox="0 0 215 115" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+    <!-- Generator: Sketch 61.2 (89653) - https://sketch.com -->
+    <title>create-new-project-md</title>
+    <desc>Created with Sketch.</desc>
+    <g id="create-new-project-md" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd">
+        <g id="Group-3" transform="translate(71.000000, 18.000000)" fill-rule="nonzero">
+            <g id="New-Blank1">
+                <path d="M6.11141667,3.90697674 L62.6947849,3.90697674 C65.9485064,3.90697674 68.5891473,6.56494969 68.5891473,9.8400273 L68.5891473,78.0669494 C68.5891473,81.342027 65.9485064,84 62.6947849,84 L6.11141667,84 C2.85769514,84 0.217054264,81.342027 0.217054264,78.0669494 L0.217054264,9.8400273 C0.217054264,6.56494969 2.85769514,3.90697674 6.11141667,3.90697674 Z" id="Path" fill="#F9F9F9"></path>
+                <path d="M8.89436241,1 L65.4777306,1 C68.7314521,1 71.372093,3.65598929 71.372093,6.9286227 L71.372093,74.5132378 C71.372093,77.7858712 68.7314521,80.4418605 65.4777306,80.4418605 L8.89436241,80.4418605 C5.64064088,80.4418605 3,77.7858712 3,74.5132378 L3,6.9286227 C3.00209243,3.65598929 5.64064088,1 8.89436241,1 Z" id="Path" fill="#FFFFFF"></path>
+                <path d="M9.2677971,2.35980136 C6.65357171,2.35980136 4.53489427,4.47043114 4.53489427,7.07940407 L4.53489427,74.3201325 C4.53489427,76.9270116 6.65147193,79.0397352 9.2677971,79.0397352 L66.0500324,79.0397352 C68.6642577,79.0397352 70.7829352,76.9291055 70.7829352,74.3201325 L70.7829352,7.07731019 C70.7829352,4.47043114 68.6663575,2.35770748 66.0500324,2.35770748 L9.2677971,2.35980136 L9.2677971,2.35980136 Z M9.2677971,0 L66.0500324,0 C69.9724203,0 73.1472868,3.16803856 73.1472868,7.07731019 L73.1472868,74.3180386 C73.1472868,78.2294042 69.9703205,81.3953488 66.0500324,81.3953488 L9.2677971,81.3953488 C5.34540913,81.3953488 2.17054264,78.2273103 2.17054264,74.3180386 L2.17054264,7.07731019 C2.17054264,3.17222631 5.34750891,0 9.2677971,0 Z" id="Shape" fill="#EEEEEE"></path>
+                <path d="M21.6234891,28.6511628 L28.9501543,28.6511628 C29.6221266,28.6511628 30.1705426,29.2387129 30.1705426,29.9534884 C30.1705426,30.6682639 29.6199589,31.255814 28.9501543,31.255814 L21.6234891,31.255814 C20.9515168,31.255814 20.4031008,30.6682639 20.4031008,29.9534884 C20.4031008,29.2387129 20.9515168,28.6511628 21.6234891,28.6511628 Z" id="Path" fill="#E1DBF1"></path>
+                <path d="M33.9142229,35.8139535 L36.1943042,35.8139535 C36.8214783,35.8139535 37.3333333,36.4015036 37.3333333,37.1162791 C37.3333333,37.8333678 36.8194552,38.4186047 36.1943042,38.4186047 L33.9142229,38.4186047 C33.2870488,38.4186047 32.7751938,37.8310546 32.7751938,37.1162791 C32.7751938,36.4015036 33.2890719,35.8139535 33.9142229,35.8139535 Z" id="Path" fill="#FC6D26"></path>
+                <path d="M24.200844,42.9767442 L28.9774506,42.9767442 C29.6343929,42.9767442 30.1705426,43.5642943 30.1705426,44.2790698 C30.1705426,44.9961585 29.6322737,45.5813953 28.9774506,45.5813953 L24.200844,45.5813953 C23.5439017,45.5813953 23.0077519,44.9938453 23.0077519,44.2790698 C23.0077519,43.5642943 23.5439017,42.9767442 24.200844,42.9767442 Z" id="Path" fill="#E1DBF1"></path>
+                <path d="M41.0770181,35.8139535 L43.3570964,35.8139535 C43.9842697,35.8139535 44.496124,36.4015036 44.496124,37.1162791 C44.496124,37.8333678 43.9822466,38.4186047 43.3570964,38.4186047 L41.0770181,38.4186047 C40.4498448,38.4186047 39.9379845,37.8310546 39.9379845,37.1162791 C39.9359673,36.4015036 40.4498448,35.8139535 41.0770181,35.8139535 Z" id="Path" fill="#FC6D26"></path>
+                <path d="M33.9372473,28.6511628 L47.89221,28.6511628 C48.5320619,28.6511628 49.0542636,29.2387129 49.0542636,29.9534884 C49.0542636,30.6682639 48.5299978,31.255814 47.89221,31.255814 L33.9372473,31.255814 C33.2973955,31.255814 32.7751938,30.6682639 32.7751938,29.9534884 C32.7751938,29.2387129 33.2994595,28.6511628 33.9372473,28.6511628 Z" id="Path" fill="#C3B8E3"></path>
+                <path d="M33.9142229,42.9767442 L36.1943042,42.9767442 C36.8214783,42.9767442 37.3333333,43.5642943 37.3333333,44.2790698 C37.3333333,44.9961585 36.8194552,45.5813953 36.1943042,45.5813953 L33.9142229,45.5813953 C33.2870488,45.5813953 32.7751938,44.9938453 32.7751938,44.2790698 C32.7751938,43.5642943 33.2890719,42.9767442 33.9142229,42.9767442 Z" id="Path" fill="#6B4FBB"></path>
+                <g id="Group" transform="translate(16.000000, 19.000000)">
+                    <circle id="Oval" fill="#FFFFFF" cx="20.8396947" cy="20.8396947" r="20.7533889"></circle>
+                    <path d="M20.8396947,41.5930835 C9.3778626,41.5930835 0.0863058062,32.3015267 0.0863058062,20.8396947 C0.0863058062,9.3778626 9.3778626,0.0863058062 20.8396947,0.0863058062 C32.3015267,0.0863058062 41.5930835,9.3778626 41.5930835,20.8396947 C41.5930835,32.3015267 32.3015267,41.5930835 20.8396947,41.5930835 Z M20.8396947,39.2207263 C30.9922045,39.2207263 39.2207263,30.9900995 39.2207263,20.8396947 C39.2207263,10.6892898 30.9900995,2.45866297 20.8396947,2.45866297 C10.6892898,2.45866297 2.45866297,10.6892898 2.45866297,20.8396947 C2.45866297,30.9900995 10.6871848,39.2207263 20.8396947,39.2207263 Z" id="Shape" fill="#EEEEEE"></path>
+                    <path d="M13.7647236,19.060953 L27.9967615,19.060953 C28.6493176,19.060953 29.1818876,19.595628 29.1818876,20.2460791 C29.1818876,20.8986352 28.6472126,21.4312052 27.9967615,21.4312052 L13.7647236,21.4312052 C13.1121675,21.4312052 12.5795975,20.8965302 12.5795975,20.2460791 C12.5795975,19.593523 13.1142725,19.060953 13.7647236,19.060953 Z" id="Path" fill="#6B4FBB"></path>
+                    <path d="M22.0669211,13.1311127 L22.0669211,27.3631506 C22.0669211,28.0157067 21.5322461,28.5482767 20.881795,28.5482767 C20.231344,28.5482767 19.696669,28.0136017 19.696669,27.3631506 L19.696669,13.1311127 C19.696669,12.4785566 20.231344,11.9459866 20.881795,11.9459866 C21.5322461,11.9459866 22.0669211,12.4785566 22.0669211,13.1311127 Z" id="Path" fill="#6B4FBB"></path>
+                </g>
+            </g>
+        </g>
+    </g>
+</svg>
\ No newline at end of file

app/assets/javascripts/projects/experiment_new_project_creation/index.js

+import Vue from 'vue';
+import NewProjectCreationApp from './components/app.vue';
+
+export default function(el, props) {
+  return new Vue({
+    el,
+    components: {
+      NewProjectCreationApp,
+    },
+    render(h) {
+      return h(NewProjectCreationApp, { props });
+    },
+  });
+}

app/assets/stylesheets/framework/blank.scss

@@ -116,3 +116,17 @@
     }
   }
 }
+
+.experiment-new-project-page-blank-state {
+  @include media-breakpoint-down(md) {
+    flex-direction: column;
+    justify-content: center;
+    text-align: center;
+  }
+}
+
+$experiment-new-project-indigo-700: #41419f;
+
+.experiment-new-project-page-blank-state-title {
+  color: $experiment-new-project-indigo-700;
+}

app/controllers/projects_controller.rb

@@ -34,6 +34,12 @@ class ProjectsController < Projects::ApplicationController
   # Project Export Rate Limit
   before_action :export_rate_limit, only: [:export, :download_export, :generate_new_export]
 
+  # Experiments
+  before_action only: [:new, :create] do
+    frontend_experimentation_tracking_data(:new_create_project_ui, 'click_tab')
+    push_frontend_feature_flag(:new_create_project_ui) if experiment_enabled?(:new_create_project_ui)
+  end
+
   layout :determine_layout
 
   def index

app/views/projects/new.html.haml

@@ -7,7 +7,11 @@
 .project-edit-container.prepend-top-default
   .project-edit-errors
     = render 'projects/errors'
-  .row
+
+  - if experiment_enabled?(:new_create_project_ui)
+    .js-experiment-new-project-creation{ data: { is_ci_cd_available: ci_cd_projects_available?, has_errors: @project.errors.any? } }
+
+  .row{ 'v-cloak': experiment_enabled?(:new_create_project_ui) }
     .col-lg-3.profile-settings-sidebar
       %h4.gl-mt-0
         = _('New project')
@@ -32,15 +36,15 @@
     .col-lg-9.js-toggle-container
       %ul.nav.nav-tabs.nav-links.gitlab-tabs{ role: 'tablist' }
         %li.nav-item{ role: 'presentation' }
-          %a.nav-link.active{ href: '#blank-project-pane', id: 'blank-project-tab', data: { toggle: 'tab', track_label: 'blank_project', track_event: "click_tab", track_value: "" }, role: 'tab' }
+          %a.nav-link.active{ href: '#blank-project-pane', id: 'blank-project-tab', data: { toggle: 'tab', experiment_track_label: 'blank_project' }, role: 'tab' }
             %span.d-none.d-sm-block= s_('ProjectsNew|Blank project')
             %span.d-block.d-sm-none= s_('ProjectsNew|Blank')
         %li.nav-item{ role: 'presentation' }
-          %a.nav-link{ href: '#create-from-template-pane', id: 'create-from-template-tab', data: { toggle: 'tab', track_label: 'create_from_template', track_event: "click_tab", track_value: "" }, role: 'tab' }
+          %a.nav-link{ href: '#create-from-template-pane', id: 'create-from-template-tab', data: { toggle: 'tab', experiment_track_label: 'create_from_template' }, role: 'tab' }
             %span.d-none.d-sm-block.qa-project-create-from-template-tab= s_('ProjectsNew|Create from template')
             %span.d-block.d-sm-none= s_('ProjectsNew|Template')
         %li.nav-item{ role: 'presentation' }
-          %a.nav-link{ href: '#import-project-pane', id: 'import-project-tab', data: { toggle: 'tab', track_label: 'import_project', track_event: "click_tab", track_value: "" }, role: 'tab' }
+          %a.nav-link{ href: '#import-project-pane', id: 'import-project-tab', data: { toggle: 'tab', experiment_track_label: 'import_project' }, role: 'tab' }
             %span.d-none.d-sm-block= s_('ProjectsNew|Import project')
             %span.d-block.d-sm-none= s_('ProjectsNew|Import')
         = render_if_exists 'projects/new_ci_cd_only_project_tab', active_tab: active_tab

ee/app/views/projects/_new_ci_cd_only_project_tab.html.haml

 - return unless ci_cd_projects_available?
 
 %li.nav-item{ class: active_when(active_tab == 'ci_cd_only'), role: 'presentation' }
-  %a.nav-link{ href: '#ci-cd-project-pane', id: 'ci-cd-project-tab', data: { toggle: 'tab', track_label: 'cicd_for_external_repo', track_event: "click_tab", track_value: "" }, role: 'tab' }
+  %a.nav-link{ href: '#ci-cd-project-pane', id: 'ci-cd-project-tab', data: { toggle: 'tab', experiment_track_label: 'cicd_for_external_repo' }, role: 'tab' }
     %span.d-none.d-sm-block
       = _('CI/CD for external repo')
     %span.d-block.d-sm-none

lib/gitlab/experimentation.rb

@@ -50,6 +50,9 @@ module Gitlab
       },
       invite_members_version_a: {
         tracking_category: 'Growth::Expansion::Experiment::InviteMembersVersionA'
+      },
+      new_create_project_ui: {
+        tracking_category: 'Manage::Import::Experiment::NewCreateProjectUi'
       }
     }.freeze
 

locale/gitlab.pot

@@ -2317,6 +2317,9 @@ msgstr ""
 msgid "An error occurred while loading milestones"
 msgstr ""
 
+msgid "An error occurred while loading project creation UI"
+msgstr ""
+
 msgid "An error occurred while loading terraform report"
 msgstr ""
 
@@ -6441,6 +6444,9 @@ msgstr ""
 msgid "Create a personal access token on your account to pull or push via %{protocol}."
 msgstr ""
 
+msgid "Create a project pre-populated with the necessary files to get you started quickly."
+msgstr ""
+
 msgid "Create an account using:"
 msgstr ""
 
@@ -14044,6 +14050,9 @@ msgstr ""
 msgid "Middleman project with Static Site Editor support"
 msgstr ""
 
+msgid "Migrate your data from an external source like GitHub, Bitbucket, or another instance of GitLab."
+msgstr ""
+
 msgid "Migrated %{success_count}/%{total_count} files."
 msgstr ""
 
@@ -17446,15 +17455,27 @@ msgstr ""
 msgid "ProjectsNew|Blank project"
 msgstr ""
 
+msgid "ProjectsNew|Connect your external repository to GitLab CI/CD."
+msgstr ""
+
 msgid "ProjectsNew|Contact an administrator to enable options for importing your project."
 msgstr ""
 
 msgid "ProjectsNew|Create"
 msgstr ""
 
+msgid "ProjectsNew|Create a blank project to house your files, plan your work, and collaborate on code, among other things."
+msgstr ""
+
+msgid "ProjectsNew|Create blank project"
+msgstr ""
+
 msgid "ProjectsNew|Create from template"
 msgstr ""
 
+msgid "ProjectsNew|Create new project"
+msgstr ""
+
 msgid "ProjectsNew|Creating project & repository."
 msgstr ""
 
@@ -17479,6 +17500,9 @@ msgstr ""
 msgid "ProjectsNew|Project description %{tag_start}(optional)%{tag_end}"
 msgstr ""
 
+msgid "ProjectsNew|Run CI/CD for external repository"
+msgstr ""
+
 msgid "ProjectsNew|Template"
 msgstr ""
 

spec/controllers/projects_controller_spec.rb

@@ -41,6 +41,27 @@ RSpec.describe ProjectsController do
           end
         end
       end
+
+      context 'with the new_create_project_ui experiment enabled and the user is part of the control group' do
+        before do
+          stub_experiment(new_create_project_ui: true)
+          stub_experiment_for_user(new_create_project_ui: false)
+          allow_any_instance_of(described_class).to receive(:experimentation_subject_id).and_return('uuid')
+        end
+
+        it 'passes the right tracking parameters to the frontend' do
+          get(:new)
+
+          expect(Gon.tracking_data).to eq(
+            {
+              category: 'Manage::Import::Experiment::NewCreateProjectUi',
+              action: 'click_tab',
+              label: 'uuid',
+              property: 'control_group'
+            }
+          )
+        end
+      end
     end
   end
 

spec/frontend/projects/experiment_new_project_creation/components/app_spec.js

+import { shallowMount } from '@vue/test-utils';
+import { GlBreadcrumb } from '@gitlab/ui';
+import App from '~/projects/experiment_new_project_creation/components/app.vue';
+import WelcomePage from '~/projects/experiment_new_project_creation/components/welcome.vue';
+import LegacyContainer from '~/projects/experiment_new_project_creation/components/legacy_container.vue';
+
+describe('Experimental new project creation app', () => {
+  let wrapper;
+
+  const createComponent = propsData => {
+    wrapper = shallowMount(App, { propsData });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+    window.location.hash = '';
+    wrapper = null;
+  });
+
+  describe('with empty hash', () => {
+    beforeEach(() => {
+      createComponent();
+    });
+
+    it('renders welcome page', () => {
+      expect(wrapper.find(WelcomePage).exists()).toBe(true);
+    });
+
+    it('does not render breadcrumbs', () => {
+      expect(wrapper.find(GlBreadcrumb).exists()).toBe(false);
+    });
+  });
+
+  it('renders blank project container if there are errors', () => {
+    createComponent({ hasErrors: true });
+    expect(wrapper.find(WelcomePage).exists()).toBe(false);
+    expect(wrapper.find(LegacyContainer).exists()).toBe(true);
+  });
+
+  describe('when hash is not empty on load', () => {
+    beforeEach(() => {
+      window.location.hash = '#blank_project';
+      createComponent();
+    });
+
+    it('renders relevant container', () => {
+      expect(wrapper.find(WelcomePage).exists()).toBe(false);
+      expect(wrapper.find(LegacyContainer).exists()).toBe(true);
+    });
+
+    it('renders breadcrumbs', () => {
+      expect(wrapper.find(GlBreadcrumb).exists()).toBe(true);
+    });
+  });
+
+  it('renders relevant container when hash changes', () => {
+    createComponent();
+    expect(wrapper.find(WelcomePage).exists()).toBe(true);
+
+    window.location.hash = '#blank_project';
+    const ev = document.createEvent('HTMLEvents');
+    ev.initEvent('hashchange', false, false);
+    window.dispatchEvent(ev);
+
+    return wrapper.vm.$nextTick().then(() => {
+      expect(wrapper.find(WelcomePage).exists()).toBe(false);
+      expect(wrapper.find(LegacyContainer).exists()).toBe(true);
+    });
+  });
+});

spec/frontend/projects/experiment_new_project_creation/components/legacy_container_spec.js

+import { shallowMount } from '@vue/test-utils';
+import LegacyContainer from '~/projects/experiment_new_project_creation/components/legacy_container.vue';
+import { setHTMLFixture, resetHTMLFixture } from 'helpers/fixtures';
+
+describe('Legacy container component', () => {
+  let wrapper;
+  let dummy;
+
+  const createComponent = propsData => {
+    wrapper = shallowMount(LegacyContainer, { propsData });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+    resetHTMLFixture();
+    wrapper = null;
+  });
+
+  describe('when selector targets real node', () => {
+    beforeEach(() => {
+      setHTMLFixture('<div class="dummy-target"></div>');
+      dummy = document.querySelector('.dummy-target');
+      createComponent({ selector: '.dummy-target' });
+    });
+
+    it('moves node inside component when mounted', () => {
+      expect(dummy.parentNode).toBe(wrapper.element);
+    });
+
+    it('moves node back when unmounted', () => {
+      wrapper.destroy();
+      expect(dummy.parentNode).toBe(document.body);
+    });
+  });
+
+  describe('when selector targets template node', () => {
+    beforeEach(() => {
+      setHTMLFixture('<template class="dummy-target">content</template>');
+      dummy = document.querySelector('.dummy-target');
+      createComponent({ selector: '.dummy-target' });
+    });
+
+    it('copies node content when mounted', () => {
+      expect(dummy.innerHTML).toEqual(wrapper.element.innerHTML);
+      expect(dummy.parentNode).toBe(document.body);
+    });
+  });
+});

spec/frontend/projects/experiment_new_project_creation/components/welcome_spec.js

+import { shallowMount } from '@vue/test-utils';
+import WelcomePage from '~/projects/experiment_new_project_creation/components/welcome.vue';
+import { mockTracking } from 'helpers/tracking_helper';
+
+describe('Welcome page', () => {
+  let wrapper;
+  let trackingSpy;
+
+  const createComponent = propsData => {
+    wrapper = shallowMount(WelcomePage, { propsData });
+  };
+
+  beforeEach(() => {
+    trackingSpy = mockTracking('_category_', document, jest.spyOn);
+    trackingSpy.mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+    window.location.hash = '';
+    wrapper = null;
+  });
+
+  it('tracks link clicks', () => {
+    createComponent({ panels: [{ name: 'test', href: '#' }] });
+    wrapper.find('a').trigger('click');
+    return wrapper.vm.$nextTick().then(() => {
+      expect(trackingSpy).toHaveBeenCalledWith(undefined, 'click_tab', { label: 'test' });
+    });
+  });
+});