Expand/collapse close & backlog lists in issue boards

The closed & backlog lists in issue boards are no collapsible. They can
be collapsed independently of each other & this selection is then saved
to the browser through localStorage. When the page loads, the code gets
the data from localStorage & determines whether to show or hide the list

Closes #23917

3 files changed, 28 insertions, 4 deletions

diff --git a/app/assets/javascripts/boards/components/board.js b/app/assets/javascripts/boards/components/board.js
index 9ba84489910..06c28baf5cb 100644
--- a/app/assets/javascripts/boards/components/board.js
+++ b/app/assets/javascripts/boards/components/board.js
@@ -1,6 +1,7 @@
 /* eslint-disable comma-dangle, space-before-function-paren, one-var */
 /* global Sortable */
 import Vue from 'vue';
+import AccessorUtilities from '../../lib/utils/accessor';
 import boardList from './board_list';
 import boardBlankState from './board_blank_state';
 import './board_delete';
@@ -22,6 +23,10 @@ gl.issueBoards.Board = Vue.extend({
     disabled: Boolean,
     issueLinkBase: String,
     rootPath: String,
+    boardId: {
+      type: String,
+      required: true,
+    },
   },
   data () {
     return {
@@ -78,7 +83,13 @@ gl.issueBoards.Board = Vue.extend({
   methods: {
     showNewIssueForm() {
       this.$refs['board-list'].showIssueForm = !this.$refs['board-list'].showIssueForm;
-    }
+    },
+    toggleExpanded(e) {
+      if (this.list.isExpandable && !e.target.classList.contains('js-no-trigger-collapse')) {
+        this.list.isExpanded = !this.list.isExpanded;
+        localStorage.setItem(`boards.${this.boardId}.${this.list.type}.expanded`, this.list.isExpanded);
+      }
+    },
   },
   mounted () {
     this.sortableOptions = gl.issueBoards.getBoardSortableDefaultOptions({
@@ -102,4 +113,11 @@ gl.issueBoards.Board = Vue.extend({
 
     this.sortable = Sortable.create(this.$el.parentNode, this.sortableOptions);
   },
+  created() {
+    if (this.list.isExpandable && AccessorUtilities.isLocalStorageAccessSafe()) {
+      const isCollapsed = localStorage.getItem(`boards.${this.boardId}.${this.list.type}.expanded`) === 'false';
+
+      this.list.isExpanded = !isCollapsed;
+    }
+  },
 });
diff --git a/app/assets/javascripts/boards/models/list.js b/app/assets/javascripts/boards/models/list.js
index 90561d0f7a8..3591b2917d8 100644
--- a/app/assets/javascripts/boards/models/list.js
+++ b/app/assets/javascripts/boards/models/list.js
@@ -12,7 +12,9 @@ class List {
     this.position = obj.position;
     this.title = obj.title;
     this.type = obj.list_type;
-    this.preset = ['closed', 'blank'].indexOf(this.type) > -1;
+    this.preset = ['backlog', 'closed', 'blank'].indexOf(this.type) > -1;
+    this.isExpandable = ['backlog', 'closed'].indexOf(this.type) > -1;
+    this.isExpanded = true;
     this.page = 1;
     this.loading = true;
     this.loadingMore = false;
diff --git a/app/assets/javascripts/boards/stores/boards_store.js b/app/assets/javascripts/boards/stores/boards_store.js
index ad9997ac334..e58a0af2242 100644
--- a/app/assets/javascripts/boards/stores/boards_store.js
+++ b/app/assets/javascripts/boards/stores/boards_store.js
@@ -31,10 +31,14 @@ gl.issueBoards.BoardsStore = {
   },
   new (listObj) {
     const list = this.addList(listObj);
+    const backlogList = this.findList('type', 'backlog', 'backlog');
 
     list
       .save()
       .then(() => {
+        // Remove any new issues from the backlog
+        // as they will be visible in the new list
+        list.issues.forEach(backlogList.removeIssue.bind(backlogList));
         this.state.lists = _.sortBy(this.state.lists, 'position');
       })
       .catch(() => {
@@ -47,7 +51,7 @@ gl.issueBoards.BoardsStore = {
   },
   shouldAddBlankState () {
     // Decide whether to add the blank state
-    return !(this.state.lists.filter(list => list.type !== 'closed')[0]);
+    return !(this.state.lists.filter(list => list.type !== 'backlog' && list.type !== 'done')[0]);
   },
   addBlankState () {
     if (!this.shouldAddBlankState() || this.welcomeIsHidden() || this.disabled) return;
@@ -100,7 +104,7 @@ gl.issueBoards.BoardsStore = {
       issueTo.removeLabel(listFrom.label);
     }
 
-    if (listTo.type === 'closed') {
+    if (listTo.type === 'closed' && listFrom.type !== 'backlog') {
       issueLists.forEach((list) => {
         list.removeIssue(issue);
       });