1 files changed, 136 insertions, 18 deletions

diff --git a/app/assets/javascripts/pipeline_editor/components/file_nav/branch_switcher.vue b/app/assets/javascripts/pipeline_editor/components/file_nav/branch_switcher.vue
index b3eba0fcc19..1acf3a03e73 100644
--- a/app/assets/javascripts/pipeline_editor/components/file_nav/branch_switcher.vue
+++ b/app/assets/javascripts/pipeline_editor/components/file_nav/branch_switcher.vue
@@ -1,32 +1,77 @@
 <script>
-import { GlDropdown, GlDropdownItem, GlDropdownSectionHeader, GlIcon } from '@gitlab/ui';
+import {
+  GlDropdown,
+  GlDropdownItem,
+  GlDropdownSectionHeader,
+  GlInfiniteScroll,
+  GlLoadingIcon,
+  GlSearchBoxByType,
+} from '@gitlab/ui';
+import { historyPushState } from '~/lib/utils/common_utils';
+import { setUrlParams } from '~/lib/utils/url_utility';
 import { s__ } from '~/locale';
-import { DEFAULT_FAILURE } from '~/pipeline_editor/constants';
+import {
+  BRANCH_PAGINATION_LIMIT,
+  BRANCH_SEARCH_DEBOUNCE,
+  DEFAULT_FAILURE,
+} from '~/pipeline_editor/constants';
 import getAvailableBranches from '~/pipeline_editor/graphql/queries/available_branches.graphql';
 import getCurrentBranch from '~/pipeline_editor/graphql/queries/client/current_branch.graphql';
 
 export default {
   i18n: {
+    dropdownHeader: s__('Switch Branch'),
     title: s__('Branches'),
     fetchError: s__('Unable to fetch branch list for this project.'),
   },
+  inputDebounce: BRANCH_SEARCH_DEBOUNCE,
   components: {
     GlDropdown,
     GlDropdownItem,
     GlDropdownSectionHeader,
-    GlIcon,
+    GlInfiniteScroll,
+    GlLoadingIcon,
+    GlSearchBoxByType,
+  },
+  inject: ['projectFullPath', 'totalBranches'],
+  props: {
+    paginationLimit: {
+      type: Number,
+      required: false,
+      default: BRANCH_PAGINATION_LIMIT,
+    },
+  },
+  data() {
+    return {
+      branches: [],
+      page: {
+        limit: this.paginationLimit,
+        offset: 0,
+        searchTerm: '',
+      },
+    };
   },
-  inject: ['projectFullPath'],
   apollo: {
-    branches: {
+    availableBranches: {
       query: getAvailableBranches,
       variables() {
         return {
+          limit: this.page.limit,
+          offset: this.page.offset,
           projectFullPath: this.projectFullPath,
+          searchPattern: this.searchPattern,
         };
       },
       update(data) {
-        return data.project?.repository?.branches || [];
+        return data.project?.repository?.branchNames || [];
+      },
+      result({ data }) {
+        const newBranches = data.project?.repository?.branchNames || [];
+
+        // check that we're not re-concatenating existing fetch results
+        if (!this.branches.includes(newBranches[0])) {
+          this.branches = this.branches.concat(newBranches);
+        }
       },
       error() {
         this.$emit('showError', {
@@ -40,26 +85,99 @@ export default {
     },
   },
   computed: {
-    hasBranchList() {
-      return this.branches?.length > 0;
+    isBranchesLoading() {
+      return this.$apollo.queries.availableBranches.loading;
+    },
+    showBranchSwitcher() {
+      return this.branches.length > 0 || this.page.searchTerm.length > 0;
+    },
+    searchPattern() {
+      if (this.page.searchTerm === '') {
+        return '*';
+      }
+
+      return `*${this.page.searchTerm}*`;
+    },
+  },
+  methods: {
+    // if there is no searchPattern, paginate by {paginationLimit} branches
+    fetchNextBranches() {
+      if (
+        this.isBranchesLoading ||
+        this.page.searchTerm.length > 0 ||
+        this.branches.length === this.totalBranches
+      ) {
+        return;
+      }
+
+      this.page = {
+        ...this.page,
+        limit: this.paginationLimit,
+        offset: this.page.offset + this.paginationLimit,
+      };
+    },
+    async selectBranch(newBranch) {
+      if (newBranch === this.currentBranch) {
+        return;
+      }
+
+      await this.$apollo.getClient().writeQuery({
+        query: getCurrentBranch,
+        data: { currentBranch: newBranch },
+      });
+
+      const updatedPath = setUrlParams({ branch_name: newBranch });
+      historyPushState(updatedPath);
+
+      this.$emit('refetchContent');
+    },
+    setSearchTerm(newSearchTerm) {
+      this.branches = [];
+      this.page = {
+        limit: newSearchTerm.trim() === '' ? this.paginationLimit : this.totalBranches,
+        offset: 0,
+        searchTerm: newSearchTerm.trim(),
+      };
     },
   },
 };
 </script>
 
 <template>
-  <gl-dropdown v-if="hasBranchList" class="gl-ml-2" :text="currentBranch" icon="branch">
+  <gl-dropdown
+    v-if="showBranchSwitcher"
+    class="gl-ml-2"
+    :header-text="$options.i18n.dropdownHeader"
+    :text="currentBranch"
+    icon="branch"
+  >
+    <gl-search-box-by-type :debounce="$options.inputDebounce" @input="setSearchTerm" />
     <gl-dropdown-section-header>
-      {{ this.$options.i18n.title }}
+      {{ $options.i18n.title }}
     </gl-dropdown-section-header>
-    <gl-dropdown-item
-      v-for="branch in branches"
-      :key="branch.name"
-      :is-checked="currentBranch === branch.name"
-      :is-check-item="true"
+
+    <gl-infinite-scroll
+      :fetched-items="branches.length"
+      :total-items="totalBranches"
+      :max-list-height="250"
+      @bottomReached="fetchNextBranches"
     >
-      <gl-icon name="check" class="gl-visibility-hidden" />
-      {{ branch.name }}
-    </gl-dropdown-item>
+      <template #items>
+        <gl-dropdown-item
+          v-for="branch in branches"
+          :key="branch"
+          :is-checked="currentBranch === branch"
+          :is-check-item="true"
+          @click="selectBranch(branch)"
+        >
+          {{ branch }}
+        </gl-dropdown-item>
+      </template>
+      <template #default>
+        <gl-dropdown-item v-if="isBranchesLoading" key="loading">
+          <gl-loading-icon size="md" />
+        </gl-dropdown-item>
+      </template>
+    </gl-infinite-scroll>
   </gl-dropdown>
 </template>