Suggests issues when typing title

This suggests possibly related issues when the user types a title.

This uses GraphQL to allow the frontend to request the exact
data that is requires. We also get free caching through the Vue Apollo
plugin.

With this we can include the ability to import .graphql files in JS
and Vue files.
Also we now have the Vue test utils library to make testing
Vue components easier.

Closes #22071

app/assets/javascripts/issuable_suggestions/components/app.vue

+<script>
+import _ from 'underscore';
+import { GlTooltipDirective } from '@gitlab/ui';
+import { __ } from '~/locale';
+import Icon from '~/vue_shared/components/icon.vue';
+import Suggestion from './item.vue';
+import query from '../queries/issues.graphql';
+
+export default {
+  components: {
+    Suggestion,
+    Icon,
+  },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
+  props: {
+    projectPath: {
+      type: String,
+      required: true,
+    },
+    search: {
+      type: String,
+      required: true,
+    },
+  },
+  apollo: {
+    issues: {
+      query,
+      debounce: 250,
+      skip() {
+        return this.isSearchEmpty;
+      },
+      update: data => data.project.issues.edges.map(({ node }) => node),
+      variables() {
+        return {
+          fullPath: this.projectPath,
+          search: this.search,
+        };
+      },
+    },
+  },
+  data() {
+    return {
+      issues: [],
+      loading: 0,
+    };
+  },
+  computed: {
+    isSearchEmpty() {
+      return _.isEmpty(this.search);
+    },
+    showSuggestions() {
+      return !this.isSearchEmpty && this.issues.length && !this.loading;
+    },
+  },
+  watch: {
+    search() {
+      if (this.isSearchEmpty) {
+        this.issues = [];
+      }
+    },
+  },
+  helpText: __(
+    'These existing issues have a similar title. It might be better to comment there instead of creating another similar issue.',
+  ),
+};
+</script>
+
+<template>
+  <div v-show="showSuggestions" class="form-group row issuable-suggestions">
+    <div v-once class="col-form-label col-sm-2 pt-0">
+      {{ __('Similar issues') }}
+      <icon
+        v-gl-tooltip.bottom
+        :title="$options.helpText"
+        :aria-label="$options.helpText"
+        name="question-o"
+        class="text-secondary suggestion-help-hover"
+      />
+    </div>
+    <div class="col-sm-10">
+      <ul class="list-unstyled m-0">
+        <li
+          v-for="(suggestion, index) in issues"
+          :key="suggestion.id"
+          :class="{
+            'append-bottom-default': index !== issues.length - 1,
+          }"
+        >
+          <suggestion :suggestion="suggestion" />
+        </li>
+      </ul>
+    </div>
+  </div>
+</template>

app/assets/javascripts/issuable_suggestions/components/item.vue

+<script>
+import _ from 'underscore';
+import { GlLink, GlTooltip, GlTooltipDirective } from '@gitlab/ui';
+import { __ } from '~/locale';
+import Icon from '~/vue_shared/components/icon.vue';
+import UserAvatarImage from '~/vue_shared/components/user_avatar/user_avatar_image.vue';
+import TimeagoTooltip from '~/vue_shared/components/time_ago_tooltip.vue';
+import timeago from '~/vue_shared/mixins/timeago';
+
+export default {
+  components: {
+    GlTooltip,
+    GlLink,
+    Icon,
+    UserAvatarImage,
+    TimeagoTooltip,
+  },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
+  mixins: [timeago],
+  props: {
+    suggestion: {
+      type: Object,
+      required: true,
+    },
+  },
+  computed: {
+    isOpen() {
+      return this.suggestion.state === 'opened';
+    },
+    isClosed() {
+      return this.suggestion.state === 'closed';
+    },
+    counts() {
+      return [
+        {
+          id: _.uniqueId(),
+          icon: 'thumb-up',
+          tooltipTitle: __('Upvotes'),
+          count: this.suggestion.upvotes,
+        },
+        {
+          id: _.uniqueId(),
+          icon: 'comment',
+          tooltipTitle: __('Comments'),
+          count: this.suggestion.userNotesCount,
+        },
+      ].filter(({ count }) => count);
+    },
+    stateIcon() {
+      return this.isClosed ? 'issue-close' : 'issue-open-m';
+    },
+    stateTitle() {
+      return this.isClosed ? __('Closed') : __('Opened');
+    },
+    closedOrCreatedDate() {
+      return this.suggestion.closedAt || this.suggestion.createdAt;
+    },
+    hasUpdated() {
+      return this.suggestion.updatedAt !== this.suggestion.createdAt;
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="suggestion-item">
+    <div class="d-flex align-items-center">
+      <icon
+        v-if="suggestion.confidential"
+        v-gl-tooltip.bottom
+        :title="__('Confidential')"
+        name="eye-slash"
+        class="suggestion-help-hover mr-1 suggestion-confidential"
+      />
+      <gl-link :href="suggestion.webUrl" target="_blank" class="suggestion bold str-truncated-100">
+        {{ suggestion.title }}
+      </gl-link>
+    </div>
+    <div class="text-secondary suggestion-footer">
+      <icon
+        ref="state"
+        :name="stateIcon"
+        :class="{
+          'suggestion-state-open': isOpen,
+          'suggestion-state-closed': isClosed,
+        }"
+        class="suggestion-help-hover"
+      />
+      <gl-tooltip :target="() => $refs.state" placement="bottom">
+        <span class="d-block">
+          <span class="bold"> {{ stateTitle }} </span> {{ timeFormated(closedOrCreatedDate) }}
+        </span>
+        <span class="text-tertiary">{{ tooltipTitle(closedOrCreatedDate) }}</span>
+      </gl-tooltip>
+      #{{ suggestion.iid }} &bull;
+      <timeago-tooltip
+        :time="suggestion.createdAt"
+        tooltip-placement="bottom"
+        class="suggestion-help-hover"
+      />
+      by
+      <gl-link :href="suggestion.author.webUrl">
+        <user-avatar-image
+          :img-src="suggestion.author.avatarUrl"
+          :size="16"
+          css-classes="mr-0 float-none"
+          tooltip-placement="bottom"
+          class="d-inline-block"
+        >
+          <span class="bold d-block">{{ __('Author') }}</span> {{ suggestion.author.name }}
+          <span class="text-tertiary">@{{ suggestion.author.username }}</span>
+        </user-avatar-image>
+      </gl-link>
+      <template v-if="hasUpdated">
+        &bull; {{ __('updated') }}
+        <timeago-tooltip
+          :time="suggestion.updatedAt"
+          tooltip-placement="bottom"
+          class="suggestion-help-hover"
+        />
+      </template>
+      <span class="suggestion-counts">
+        <span
+          v-for="{ count, icon, tooltipTitle, id } in counts"
+          :key="id"
+          v-gl-tooltip.bottom
+          :title="tooltipTitle"
+          class="suggestion-help-hover prepend-left-8 text-tertiary"
+        >
+          <icon :name="icon" /> {{ count }}
+        </span>
+      </span>
+    </div>
+  </div>
+</template>

app/assets/javascripts/issuable_suggestions/index.js

+import Vue from 'vue';
+import VueApollo from 'vue-apollo';
+import defaultClient from '~/lib/graphql';
+import App from './components/app.vue';
+
+Vue.use(VueApollo);
+
+export default function() {
+  const el = document.getElementById('js-suggestions');
+  const issueTitle = document.getElementById('issue_title');
+  const { projectPath } = el.dataset;
+  const apolloProvider = new VueApollo({
+    defaultClient,
+  });
+
+  return new Vue({
+    el,
+    apolloProvider,
+    data() {
+      return {
+        search: issueTitle.value,
+      };
+    },
+    mounted() {
+      issueTitle.addEventListener('input', () => {
+        this.search = issueTitle.value;
+      });
+    },
+    render(h) {
+      return h(App, {
+        props: {
+          projectPath,
+          search: this.search,
+        },
+      });
+    },
+  });
+}

app/assets/javascripts/issuable_suggestions/queries/issues.graphql

+query issueSuggestion($fullPath: ID!, $search: String) {
+  project(fullPath: $fullPath) {
+    issues(search: $search, sort: updated_desc, first: 5) {
+      edges {
+        node {
+          iid
+          title
+          confidential
+          userNotesCount
+          upvotes
+          webUrl
+          state
+          closedAt
+          createdAt
+          updatedAt
+          author {
+            name
+            username
+            avatarUrl
+            webUrl
+          }
+        }
+      }
+    }
+  }
+}

app/assets/javascripts/lib/graphql.js

+import ApolloClient from 'apollo-boost';
+import csrf from '~/lib/utils/csrf';
+
+export default new ApolloClient({
+  uri: `${gon.relative_url_root}/api/graphql`,
+  headers: {
+    [csrf.headerKey]: csrf.token,
+  },
+});

app/assets/javascripts/pages/projects/issues/form.js

@@ -7,6 +7,7 @@ import LabelsSelect from '~/labels_select';
 import MilestoneSelect from '~/milestone_select';
 import ShortcutsNavigation from '~/behaviors/shortcuts/shortcuts_navigation';
 import IssuableTemplateSelectors from '~/templates/issuable_template_selectors';
+import initSuggestions from '~/issuable_suggestions';
 export default () => {
   new ShortcutsNavigation();
@@ -15,4 +16,8 @@ export default () => {
   new LabelsSelect();
   new MilestoneSelect();
   new IssuableTemplateSelectors();
+
+  if (gon.features.issueSuggestions && gon.features.graphql) {
+    initSuggestions();
+  }
 };

app/assets/stylesheets/pages/issuable.scss

@@ -938,3 +938,37 @@
     }
   }
 }
+
+.issuable-suggestions svg {
+  vertical-align: sub;
+}
+
+.suggestion-item a {
+  color: initial;
+}
+
+.suggestion-confidential {
+  color: $orange-600;
+}
+
+.suggestion-state-open {
+  color: $green-500;
+}
+
+.suggestion-state-closed {
+  color: $blue-500;
+}
+
+.suggestion-help-hover {
+  cursor: help;
+}
+
+.suggestion-footer {
+  font-size: 12px;
+  line-height: 15px;
+
+  .avatar {
+    margin-top: -3px;
+    border: 0;
+  }
+}

app/controllers/projects/issues_controller.rb

@@ -38,6 +38,8 @@ class Projects::IssuesController < Projects::ApplicationController
   # Allow create a new branch and empty WIP merge request from current issue
   before_action :authorize_create_merge_request_from!, only: [:create_merge_request]
+  before_action :set_suggested_issues_feature_flags, only: [:new]
+
   respond_to :html
   def index
@@ -263,4 +265,9 @@ class Projects::IssuesController < Projects::ApplicationController
     # 3. https://gitlab.com/gitlab-org/gitlab-ce/issues/42426
     Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/42422')
   end
+
+  def set_suggested_issues_feature_flags
+    push_frontend_feature_flag(:graphql)
+    push_frontend_feature_flag(:issue_suggestions)
+  end
 end

app/graphql/resolvers/issues_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class IssuesResolver < BaseResolver
+    extend ActiveSupport::Concern
+
+    argument :search, GraphQL::STRING_TYPE,
+              required: false
+    argument :sort, Types::Sort,
+              required: false,
+              default_value: 'created_desc'
+
+    type Types::IssueType, null: true
+
+    alias_method :project, :object
+
+    def resolve(**args)
+      # Will need to be be made group & namespace aware with
+      # https://gitlab.com/gitlab-org/gitlab-ce/issues/54520
+      args[:project_id] = project.id
+
+      IssuesFinder.new(context[:current_user], args).execute
+    end
+  end
+end

app/graphql/types/issue_type.rb

+# frozen_string_literal: true
+
+module Types
+  class IssueType < BaseObject
+    expose_permissions Types::PermissionTypes::Issue
+
+    graphql_name 'Issue'
+
+    present_using IssuePresenter
+
+    field :iid, GraphQL::ID_TYPE, null: false
+    field :title, GraphQL::STRING_TYPE, null: false
+    field :description, GraphQL::STRING_TYPE, null: true
+    field :state, GraphQL::STRING_TYPE, null: false
+
+    field :author, Types::UserType,
+          null: false,
+          resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchModelLoader.new(User, obj.author_id).find } do
+      authorize :read_user
+    end
+
+    field :assignees, Types::UserType.connection_type, null: true
+
+    field :labels, Types::LabelType.connection_type, null: true
+    field :milestone, Types::MilestoneType,
+          null: true,
+          resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchModelLoader.new(Milestone, obj.milestone_id).find } do
+      authorize :read_milestone
+    end
+
+    field :due_date, Types::TimeType, null: true
+    field :confidential, GraphQL::BOOLEAN_TYPE, null: false
+    field :discussion_locked, GraphQL::BOOLEAN_TYPE,
+          null: false,
+          resolve: -> (obj, _args, _ctx) { !!obj.discussion_locked }
+
+    field :upvotes, GraphQL::INT_TYPE, null: false
+    field :downvotes, GraphQL::INT_TYPE, null: false
+    field :user_notes_count, GraphQL::INT_TYPE, null: false
+    field :web_url, GraphQL::STRING_TYPE, null: false
+
+    field :closed_at, Types::TimeType, null: true
+
+    field :created_at, Types::TimeType, null: false
+    field :updated_at, Types::TimeType, null: false
+  end
+end

app/graphql/types/label_type.rb

+# frozen_string_literal: true
+
+module Types
+  class LabelType < BaseObject
+    graphql_name 'Label'
+
+    field :description, GraphQL::STRING_TYPE, null: true
+    field :title, GraphQL::STRING_TYPE, null: false
+    field :color, GraphQL::STRING_TYPE, null: false
+    field :text_color, GraphQL::STRING_TYPE, null: false
+  end
+end

app/graphql/types/milestone_type.rb

+# frozen_string_literal: true
+
+module Types
+  class MilestoneType < BaseObject
+    graphql_name 'Milestone'
+
+    field :description, GraphQL::STRING_TYPE, null: true
+    field :title, GraphQL::STRING_TYPE, null: false
+    field :state, GraphQL::STRING_TYPE, null: false
+
+    field :due_date, Types::TimeType, null: true
+    field :start_date, Types::TimeType, null: true
+
+    field :created_at, Types::TimeType, null: false
+    field :updated_at, Types::TimeType, null: false
+  end
+end

app/graphql/types/order.rb

+# frozen_string_literal: true
+
+module Types
+  class Types::Order < Types::BaseEnum
+    value "id", "Created at date"
+    value "updated_at", "Updated at date"
+  end
+end

app/graphql/types/permission_types/issue.rb

+# frozen_string_literal: true
+
+module Types
+  module PermissionTypes
+    class Issue < BasePermissionType
+      description 'Check permissions for the current user on a issue'
+      graphql_name 'IssuePermissions'
+
+      abilities :read_issue, :admin_issue,
+                :update_issue, :create_note,
+                :reopen_issue
+    end
+  end
+end

app/graphql/types/project_type.rb

@@ -73,6 +73,11 @@ module Types
       authorize :read_merge_request
     end
+    field :issues,
+          Types::IssueType.connection_type,
+          null: true,
+          resolver: Resolvers::IssuesResolver
+
     field :pipelines,
           Types::Ci::PipelineType.connection_type,
           null: false,

app/graphql/types/sort.rb

+# frozen_string_literal: true
+
+module Types
+  class Types::Sort < Types::BaseEnum
+    value "updated_desc", "Updated at descending order"
+    value "updated_asc", "Updated at ascending order"
+    value "created_desc", "Created at descending order"
+    value "created_asc", "Created at ascending order"
+  end
+end

app/graphql/types/user_type.rb

+# frozen_string_literal: true
+
+module Types
+  class UserType < BaseObject
+    graphql_name 'User'
+
+    present_using UserPresenter
+
+    field :name, GraphQL::STRING_TYPE, null: false
+    field :username, GraphQL::STRING_TYPE, null: false
+    field :avatar_url, GraphQL::STRING_TYPE, null: false
+    field :web_url, GraphQL::STRING_TYPE, null: false
+  end
+end

app/policies/milestone_policy.rb

+# frozen_string_literal: true
+
+class MilestonePolicy < BasePolicy
+  delegate { @subject.project }
+end

app/presenters/issue_presenter.rb

+# frozen_string_literal: true
+
+class IssuePresenter < Gitlab::View::Presenter::Delegated
+  presents :issue
+
+  def web_url
+    Gitlab::UrlBuilder.build(issue)
+  end
+end

app/presenters/user_presenter.rb

+# frozen_string_literal: true
+
+class UserPresenter < Gitlab::View::Presenter::Delegated
+  presents :user
+
+  def web_url
+    Gitlab::Routing.url_helpers.user_url(user)
+  end
+end