Extract setCurrentBoard() from BoardsSelector into BoardsStoreEE

ee/app/assets/javascripts/boards/components/boards_selector.vue

@@ -161,9 +161,7 @@ export default {
     },
   },
   created() {
-    this.state.currentBoard = this.currentBoard;
-    boardsStore.state.assignees = [];
-    boardsStore.state.milestones = [];
+    boardsStore.setCurrentBoard(this.currentBoard);
     $('#js-add-list').on('hide.bs.dropdown', this.handleDropdownHide);
     $('.js-new-board-list-tabs').on('click', this.handleDropdownTabClick);
   },

ee/app/assets/javascripts/boards/stores/boards_store_ee.js

@@ -16,6 +16,7 @@ class BoardsStoreEE {
       this.addPromotion();
     };
     this.store.loadList = (listPath, listType) => this.loadList(listPath, listType);
+    this.store.setCurrentBoard = board => this.setCurrentBoard(board);
     this.store.removePromotionState = () => {
       this.removePromotion();
     };
@@ -156,6 +157,13 @@ class BoardsStoreEE {
     return parseBoolean(Cookies.get('promotion_issue_board_hidden'));
   }
 
+  setCurrentBoard(board) {
+    const { state } = this.store;
+    state.currentBoard = board;
+    state.assignees = [];
+    state.milestones = [];
+  }
+
   updateWeight(newWeight, id) {
     const { issue } = this.store.detail;
     if (issue.id === id && issue.sidebarInfoEndpoint) {

ee/spec/frontend/boards/stores/boards_store_ee_spec.js

@@ -56,4 +56,35 @@ describe('BoardsStoreEE', () => {
       });
     });
   });
+
+  describe('setCurrentBoard', () => {
+    const dummyBoard = 'skateboard';
+
+    it('sets the current board', () => {
+      const { state } = BoardsStoreEE.store;
+      state.currentBoard = null;
+
+      BoardsStoreEE.setCurrentBoard(dummyBoard);
+
+      expect(state.currentBoard).toEqual(dummyBoard);
+    });
+
+    it('resets assignees', () => {
+      const { state } = BoardsStoreEE.store;
+      state.assignees = 'some assignees';
+
+      BoardsStoreEE.setCurrentBoard(dummyBoard);
+
+      expect(state.assignees).toEqual([]);
+    });
+
+    it('resets milestones', () => {
+      const { state } = BoardsStoreEE.store;
+      state.milestones = 'some milestones';
+
+      BoardsStoreEE.setCurrentBoard(dummyBoard);
+
+      expect(state.milestones).toEqual([]);
+    });
+  });
 });