Merge branch '233441-epic-boards-drag-drop-epic-between-lists' into 'master'

Epic Boards - Drag & Drop epic between lists

See merge request gitlab-org/gitlab!56170

app/assets/javascripts/boards/boards_util.js

@@ -113,31 +113,31 @@ export function formatIssueInput(issueInput, boardConfig) {
   };
 }
 
-export function moveIssueListHelper(issue, fromList, toList) {
-  const updatedIssue = issue;
+export function moveItemListHelper(item, fromList, toList) {
+  const updatedItem = item;
   if (
     toList.listType === ListType.label &&
-    !updatedIssue.labels.find((label) => label.id === toList.label.id)
+    !updatedItem.labels.find((label) => label.id === toList.label.id)
   ) {
-    updatedIssue.labels.push(toList.label);
+    updatedItem.labels.push(toList.label);
   }
   if (fromList?.label && fromList.listType === ListType.label) {
-    updatedIssue.labels = updatedIssue.labels.filter((label) => fromList.label.id !== label.id);
+    updatedItem.labels = updatedItem.labels.filter((label) => fromList.label.id !== label.id);
   }
 
   if (
     toList.listType === ListType.assignee &&
-    !updatedIssue.assignees.find((assignee) => assignee.id === toList.assignee.id)
+    !updatedItem.assignees.find((assignee) => assignee.id === toList.assignee.id)
   ) {
-    updatedIssue.assignees.push(toList.assignee);
+    updatedItem.assignees.push(toList.assignee);
   }
   if (fromList?.assignee && fromList.listType === ListType.assignee) {
-    updatedIssue.assignees = updatedIssue.assignees.filter(
+    updatedItem.assignees = updatedItem.assignees.filter(
       (assignee) => assignee.id !== fromList.assignee.id,
     );
   }
 
-  return updatedIssue;
+  return updatedItem;
 }
 
 export function isListDraggable(list) {

app/assets/javascripts/boards/components/board_card.vue

@@ -13,7 +13,7 @@ export default {
       default: () => ({}),
       required: false,
     },
-    issue: {
+    item: {
       type: Object,
       default: () => ({}),
       required: false,
@@ -33,12 +33,12 @@ export default {
     ...mapState(['selectedBoardItems', 'activeId']),
     ...mapGetters(['isSwimlanesOn']),
     isActive() {
-      return this.issue.id === this.activeId;
+      return this.item.id === this.activeId;
     },
     multiSelectVisible() {
       return (
         !this.activeId &&
-        this.selectedBoardItems.findIndex((boardItem) => boardItem.id === this.issue.id) > -1
+        this.selectedBoardItems.findIndex((boardItem) => boardItem.id === this.item.id) > -1
       );
     },
   },
@@ -50,9 +50,9 @@ export default {
 
       const isMultiSelect = e.ctrlKey || e.metaKey;
       if (isMultiSelect) {
-        this.toggleBoardItemMultiSelection(this.issue);
+        this.toggleBoardItemMultiSelection(this.item);
       } else {
-        this.toggleBoardItem({ boardItem: this.issue });
+        this.toggleBoardItem({ boardItem: this.item });
       }
     },
   },
@@ -64,18 +64,18 @@ export default {
     data-qa-selector="board_card"
     :class="{
       'multi-select': multiSelectVisible,
-      'user-can-drag': !disabled && issue.id,
-      'is-disabled': disabled || !issue.id,
+      'user-can-drag': !disabled && item.id,
+      'is-disabled': disabled || !item.id,
       'is-active': isActive,
     }"
     :index="index"
-    :data-issue-id="issue.id"
-    :data-issue-iid="issue.iid"
-    :data-issue-path="issue.referencePath"
+    :data-item-id="item.id"
+    :data-item-iid="item.iid"
+    :data-item-path="item.referencePath"
     data-testid="board_card"
     class="board-card gl-p-5 gl-rounded-base"
     @mouseup="toggleIssue($event)"
   >
-    <board-card-inner :list="list" :item="issue" :update-filters="true" />
+    <board-card-inner :list="list" :item="item" :update-filters="true" />
   </li>
 </template>

app/assets/javascripts/boards/components/board_content.vue

@@ -49,7 +49,7 @@ export default {
         : this.lists;
     },
     canDragColumns() {
-      return this.glFeatures.graphqlBoardLists && this.canAdminList;
+      return !this.isEpicBoard && this.glFeatures.graphqlBoardLists && this.canAdminList;
     },
     boardColumnWrapper() {
       return this.canDragColumns ? Draggable : 'div';
@@ -80,6 +80,7 @@ export default {
 
     handleDragOnEnd(params) {
       sortableEnd();
+      if (this.isEpicBoard) return;
 
       const { item, newIndex, oldIndex, to } = params;
 

app/assets/javascripts/boards/components/board_list.vue

 <script>
 import { GlLoadingIcon } from '@gitlab/ui';
 import Draggable from 'vuedraggable';
-import { mapActions, mapGetters, mapState } from 'vuex';
+import { mapActions, mapState } from 'vuex';
 import { sortableStart, sortableEnd } from '~/boards/mixins/sortable_default_options';
 import { sprintf, __ } from '~/locale';
 import defaultSortableConfig from '~/sortable/sortable_config';
@@ -49,7 +49,6 @@ export default {
   },
   computed: {
     ...mapState(['pageInfoByListId', 'listsFlags']),
-    ...mapGetters(['isEpicBoard']),
     paginatedIssueText() {
       return sprintf(__('Showing %{pageSize} of %{total} issues'), {
         pageSize: this.boardItems.length,
@@ -70,13 +69,13 @@ export default {
     },
     listRef() {
       // When  list is draggable, the reference to the list needs to be accessed differently
-      return this.canAdminList && !this.isEpicBoard ? this.$refs.list.$el : this.$refs.list;
+      return this.canAdminList ? this.$refs.list.$el : this.$refs.list;
     },
     showingAllIssues() {
       return this.boardItems.length === this.list.issuesCount;
     },
     treeRootWrapper() {
-      return this.canAdminList && !this.isEpicBoard ? Draggable : 'ul';
+      return this.canAdminList ? Draggable : 'ul';
     },
     treeRootOptions() {
       const options = {
@@ -113,7 +112,7 @@ export default {
     this.listRef.removeEventListener('scroll', this.onScroll);
   },
   methods: {
-    ...mapActions(['fetchItemsForList', 'moveIssue']),
+    ...mapActions(['fetchItemsForList', 'moveItem']),
     listHeight() {
       return this.listRef.getBoundingClientRect().height;
     },
@@ -149,40 +148,40 @@ export default {
     handleDragOnEnd(params) {
       sortableEnd();
       const { newIndex, oldIndex, from, to, item } = params;
-      const { issueId, issueIid, issuePath } = item.dataset;
+      const { itemId, itemIid, itemPath } = item.dataset;
       const { children } = to;
       let moveBeforeId;
       let moveAfterId;
 
-      const getIssueId = (el) => Number(el.dataset.issueId);
+      const getItemId = (el) => Number(el.dataset.itemId);
 
-      // If issue is being moved within the same list
+      // If item is being moved within the same list
       if (from === to) {
         if (newIndex > oldIndex && children.length > 1) {
-          // If issue is being moved down we look for the issue that ends up before
-          moveBeforeId = getIssueId(children[newIndex]);
+          // If item is being moved down we look for the item that ends up before
+          moveBeforeId = getItemId(children[newIndex]);
         } else if (newIndex < oldIndex && children.length > 1) {
-          // If issue is being moved up we look for the issue that ends up after
-          moveAfterId = getIssueId(children[newIndex]);
+          // If item is being moved up we look for the item that ends up after
+          moveAfterId = getItemId(children[newIndex]);
         } else {
-          // If issue remains in the same list at the same position we do nothing
+          // If item remains in the same list at the same position we do nothing
           return;
         }
       } else {
-        // We look for the issue that ends up before the moved issue if it exists
+        // We look for the item that ends up before the moved item if it exists
         if (children[newIndex - 1]) {
-          moveBeforeId = getIssueId(children[newIndex - 1]);
+          moveBeforeId = getItemId(children[newIndex - 1]);
         }
-        // We look for the issue that ends up after the moved issue if it exists
+        // We look for the item that ends up after the moved item if it exists
         if (children[newIndex]) {
-          moveAfterId = getIssueId(children[newIndex]);
+          moveAfterId = getItemId(children[newIndex]);
         }
       }
 
-      this.moveIssue({
-        issueId,
-        issueIid,
-        issuePath,
+      this.moveItem({
+        itemId,
+        itemIid,
+        itemPath,
         fromListId: from.dataset.listId,
         toListId: to.dataset.listId,
         moveBeforeId,
@@ -227,7 +226,7 @@ export default {
         :key="item.id"
         :index="index"
         :list="list"
-        :issue="item"
+        :item="item"
         :disabled="disabled"
       />
       <li v-if="showCount" class="board-list-count gl-text-center" data-issue-id="-1">

app/assets/javascripts/boards/stores/actions.js

@@ -325,17 +325,21 @@ export default {
     commit(types.RESET_ISSUES);
   },
 
+  moveItem: ({ dispatch }) => {
+    dispatch('moveIssue');
+  },
+
   moveIssue: (
     { state, commit },
-    { issueId, issueIid, issuePath, fromListId, toListId, moveBeforeId, moveAfterId },
+    { itemId, itemIid, itemPath, fromListId, toListId, moveBeforeId, moveAfterId },
   ) => {
-    const originalIssue = state.boardItems[issueId];
+    const originalIssue = state.boardItems[itemId];
     const fromList = state.boardItemsByListId[fromListId];
-    const originalIndex = fromList.indexOf(Number(issueId));
+    const originalIndex = fromList.indexOf(Number(itemId));
     commit(types.MOVE_ISSUE, { originalIssue, fromListId, toListId, moveBeforeId, moveAfterId });
 
     const { boardId } = state;
-    const [fullProjectPath] = issuePath.split(/[#]/);
+    const [fullProjectPath] = itemPath.split(/[#]/);
 
     gqlClient
       .mutate({
@@ -343,7 +347,7 @@ export default {
         variables: {
           projectPath: fullProjectPath,
           boardId: fullBoardId(boardId),
-          iid: issueIid,
+          iid: itemIid,
           fromListId: getIdFromGraphQLId(fromListId),
           toListId: getIdFromGraphQLId(toListId),
           moveBeforeId,
@@ -352,7 +356,7 @@ export default {
       })
       .then(({ data }) => {
         if (data?.issueMoveList?.errors.length) {
-          commit(types.MOVE_ISSUE_FAILURE, { originalIssue, fromListId, toListId, originalIndex });
+          throw new Error();
         } else {
           const issue = data.issueMoveList?.issue;
           commit(types.MOVE_ISSUE_SUCCESS, { issue });

app/assets/javascripts/boards/stores/mutations.js

@@ -2,7 +2,8 @@ import { pull, union } from 'lodash';
 import Vue from 'vue';
 import { getIdFromGraphQLId } from '~/graphql_shared/utils';
 import { s__ } from '~/locale';
-import { formatIssue, moveIssueListHelper } from '../boards_util';
+import { formatIssue, moveItemListHelper } from '../boards_util';
+import { issuableTypes } from '../constants';
 import * as mutationTypes from './mutation_types';
 
 const notImplemented = () => {
@@ -10,13 +11,21 @@ const notImplemented = () => {
   throw new Error('Not implemented!');
 };
 
-export const removeIssueFromList = ({ state, listId, issueId }) => {
-  Vue.set(state.boardItemsByListId, listId, pull(state.boardItemsByListId[listId], issueId));
+const updateListItemsCount = ({ state, listId, value }) => {
   const list = state.boardLists[listId];
-  Vue.set(state.boardLists, listId, { ...list, issuesCount: list.issuesCount - 1 });
+  if (state.issuableType === issuableTypes.epic) {
+    Vue.set(state.boardLists, listId, { ...list, epicsCount: list.epicsCount + value });
+  } else {
+    Vue.set(state.boardLists, listId, { ...list, issuesCount: list.issuesCount + value });
+  }
+};
+
+export const removeItemFromList = ({ state, listId, itemId }) => {
+  Vue.set(state.boardItemsByListId, listId, pull(state.boardItemsByListId[listId], itemId));
+  updateListItemsCount({ state, listId, value: -1 });
 };
 
-export const addIssueToList = ({ state, listId, issueId, moveBeforeId, moveAfterId, atIndex }) => {
+export const addItemToList = ({ state, listId, itemId, moveBeforeId, moveAfterId, atIndex }) => {
   const listIssues = state.boardItemsByListId[listId];
   let newIndex = atIndex || 0;
   if (moveBeforeId) {
@@ -24,10 +33,9 @@ export const addIssueToList = ({ state, listId, issueId, moveBeforeId, moveAfter
   } else if (moveAfterId) {
     newIndex = listIssues.indexOf(moveAfterId);
   }
-  listIssues.splice(newIndex, 0, issueId);
+  listIssues.splice(newIndex, 0, itemId);
   Vue.set(state.boardItemsByListId, listId, listIssues);
-  const list = state.boardLists[listId];
-  Vue.set(state.boardLists, listId, { ...list, issuesCount: list.issuesCount + 1 });
+  updateListItemsCount({ state, listId, value: 1 });
 };
 
 export default {
@@ -182,11 +190,11 @@ export default {
     const fromList = state.boardLists[fromListId];
     const toList = state.boardLists[toListId];
 
-    const issue = moveIssueListHelper(originalIssue, fromList, toList);
+    const issue = moveItemListHelper(originalIssue, fromList, toList);
     Vue.set(state.boardItems, issue.id, issue);
 
-    removeIssueFromList({ state, listId: fromListId, issueId: issue.id });
-    addIssueToList({ state, listId: toListId, issueId: issue.id, moveBeforeId, moveAfterId });
+    removeItemFromList({ state, listId: fromListId, itemId: issue.id });
+    addItemToList({ state, listId: toListId, itemId: issue.id, moveBeforeId, moveAfterId });
   },
 
   [mutationTypes.MOVE_ISSUE_SUCCESS]: (state, { issue }) => {
@@ -200,11 +208,11 @@ export default {
   ) => {
     state.error = s__('Boards|An error occurred while moving the issue. Please try again.');
     Vue.set(state.boardItems, originalIssue.id, originalIssue);
-    removeIssueFromList({ state, listId: toListId, issueId: originalIssue.id });
-    addIssueToList({
+    removeItemFromList({ state, listId: toListId, itemId: originalIssue.id });
+    addItemToList({
       state,
       listId: fromListId,
-      issueId: originalIssue.id,
+      itemId: originalIssue.id,
       atIndex: originalIndex,
     });
   },
@@ -226,10 +234,10 @@ export default {
   },
 
   [mutationTypes.ADD_ISSUE_TO_LIST]: (state, { list, issue, position }) => {
-    addIssueToList({
+    addItemToList({
       state,
       listId: list.id,
-      issueId: issue.id,
+      itemId: issue.id,
       atIndex: position,
     });
     Vue.set(state.boardItems, issue.id, issue);
@@ -237,11 +245,11 @@ export default {
 
   [mutationTypes.ADD_ISSUE_TO_LIST_FAILURE]: (state, { list, issueId }) => {
     state.error = s__('Boards|An error occurred while creating the issue. Please try again.');
-    removeIssueFromList({ state, listId: list.id, issueId });
+    removeItemFromList({ state, listId: list.id, itemId: issueId });
   },
 
   [mutationTypes.REMOVE_ISSUE_FROM_LIST]: (state, { list, issue }) => {
-    removeIssueFromList({ state, listId: list.id, issueId: issue.id });
+    removeItemFromList({ state, listId: list.id, itemId: issue.id });
     Vue.delete(state.boardItems, issue.id);
   },
 

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

@@ -118,7 +118,7 @@ export default {
     handleDragOnEnd(params) {
       document.body.classList.remove('is-dragging');
       const { newIndex, oldIndex, from, to, item } = params;
-      const { issueId, issueIid, issuePath } = item.dataset;
+      const { itemId, itemIid, itemPath } = item.dataset;
       const { children } = to;
       let moveBeforeId;
       let moveAfterId;
@@ -127,10 +127,10 @@ export default {
       if (from === to) {
         if (newIndex > oldIndex && children.length > 1) {
           // If issue is being moved down we look for the issue that ends up before
-          moveBeforeId = Number(children[newIndex].dataset.issueId);
+          moveBeforeId = Number(children[newIndex].dataset.itemId);
         } else if (newIndex < oldIndex && children.length > 1) {
           // If issue is being moved up we look for the issue that ends up after
-          moveAfterId = Number(children[newIndex].dataset.issueId);
+          moveAfterId = Number(children[newIndex].dataset.itemId);
         } else {
           // If issue remains in the same list at the same position we do nothing
           return;
@@ -138,18 +138,18 @@ export default {
       } else {
         // We look for the issue that ends up before the moved issue if it exists
         if (children[newIndex - 1]) {
-          moveBeforeId = Number(children[newIndex - 1].dataset.issueId);
+          moveBeforeId = Number(children[newIndex - 1].dataset.itemId);
         }
         // We look for the issue that ends up after the moved issue if it exists
         if (children[newIndex]) {
-          moveAfterId = Number(children[newIndex].dataset.issueId);
+          moveAfterId = Number(children[newIndex].dataset.itemId);
         }
       }
 
       this.moveIssue({
-        issueId,
-        issueIid,
-        issuePath,
+        itemId,
+        itemIid,
+        itemPath,
         fromListId: from.dataset.listId,
         toListId: to.dataset.listId,
         moveBeforeId,
@@ -187,7 +187,7 @@ export default {
           :key="issue.id"
           :index="index"
           :list="list"
-          :issue="issue"
+          :item="issue"
           :disabled="disabled || !canAdminEpic"
         />
         <gl-loading-icon v-if="isLoadingMore && isUnassignedIssuesLane" size="sm" class="gl-py-3" />

ee/app/assets/javascripts/boards/graphql/epic_move_list.mutation.graphql

+mutation EpicMoveList(
+  $epicId: EpicID!
+  $boardId: BoardsEpicBoardID!
+  $fromListId: BoardsEpicListID!
+  $toListId: BoardsEpicListID!
+) {
+  epicMoveList(
+    input: { epicId: $epicId, boardId: $boardId, fromListId: $fromListId, toListId: $toListId }
+  ) {
+    errors
+  }
+}

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

@@ -32,6 +32,7 @@ import { EpicFilterType, IterationFilterType, GroupByParamType } from '../consta
 import epicQuery from '../graphql/epic.query.graphql';
 import createEpicBoardListMutation from '../graphql/epic_board_list_create.mutation.graphql';
 import epicBoardListsQuery from '../graphql/epic_board_lists.query.graphql';
+import epicMoveListMutation from '../graphql/epic_move_list.mutation.graphql';
 import epicsSwimlanesQuery from '../graphql/epics_swimlanes.query.graphql';
 import groupBoardMilestonesQuery from '../graphql/group_board_milestones.query.graphql';
 import issueMoveListMutation from '../graphql/issue_move_list.mutation.graphql';
@@ -484,13 +485,21 @@ export default {
     });
   },
 
+  moveItem: ({ getters, dispatch }, params) => {
+    if (!getters.isEpicBoard) {
+      dispatch('moveIssue', params);
+    } else {
+      dispatch('moveEpic', params);
+    }
+  },
+
   moveIssue: (
     { state, commit },
-    { issueId, issueIid, issuePath, fromListId, toListId, moveBeforeId, moveAfterId, epicId },
+    { itemId, itemIid, itemPath, fromListId, toListId, moveBeforeId, moveAfterId, epicId },
   ) => {
-    const originalIssue = state.boardItems[issueId];
+    const originalIssue = state.boardItems[itemId];
     const fromList = state.boardItemsByListId[fromListId];
-    const originalIndex = fromList.indexOf(Number(issueId));
+    const originalIndex = fromList.indexOf(Number(itemId));
     commit(types.MOVE_ISSUE, {
       originalIssue,
       fromListId,
@@ -501,7 +510,7 @@ export default {
     });
 
     const { boardId } = state;
-    const [fullProjectPath] = issuePath.split(/[#]/);
+    const [fullProjectPath] = itemPath.split(/[#]/);
 
     gqlClient
       .mutate({
@@ -509,7 +518,7 @@ export default {
         variables: {
           projectPath: fullProjectPath,
           boardId: fullBoardId(boardId),
-          iid: issueIid,
+          iid: itemIid,
           fromListId: getIdFromGraphQLId(fromListId),
           toListId: getIdFromGraphQLId(toListId),
           moveBeforeId,
@@ -519,7 +528,7 @@ export default {
       })
       .then(({ data }) => {
         if (data?.issueMoveList?.errors.length) {
-          commit(types.MOVE_ISSUE_FAILURE, { originalIssue, fromListId, toListId, originalIndex });
+          throw new Error();
         } else {
           const issue = data.issueMoveList?.issue;
           commit(types.MOVE_ISSUE_SUCCESS, { issue });
@@ -530,6 +539,40 @@ export default {
       );
   },
 
+  moveEpic: ({ state, commit }, { itemId, fromListId, toListId, moveBeforeId, moveAfterId }) => {
+    const originalEpic = state.boardItems[itemId];
+    const fromList = state.boardItemsByListId[fromListId];
+    const originalIndex = fromList.indexOf(Number(itemId));
+    commit(types.MOVE_EPIC, {
+      originalEpic,
+      fromListId,
+      toListId,
+      moveBeforeId,
+      moveAfterId,
+    });
+
+    const { boardId } = state;
+
+    gqlClient
+      .mutate({
+        mutation: epicMoveListMutation,
+        variables: {
+          epicId: fullEpicId(itemId),
+          boardId: fullEpicBoardId(boardId),
+          fromListId,
+          toListId,
+        },
+      })
+      .then(({ data }) => {
+        if (data?.epicMoveList?.errors.length) {
+          throw new Error();
+        }
+      })
+      .catch(() =>
+        commit(types.MOVE_EPIC_FAILURE, { originalEpic, fromListId, toListId, originalIndex }),
+      );
+  },
+
   fetchLists: ({ getters, dispatch }) => {
     if (!getters.isEpicBoard) {
       dispatch('fetchIssueLists');

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

@@ -31,6 +31,8 @@ export const SET_FILTERS = 'SET_FILTERS';
 export const MOVE_ISSUE = 'MOVE_ISSUE';
 export const MOVE_ISSUE_SUCCESS = 'MOVE_ISSUE_SUCCESS';
 export const MOVE_ISSUE_FAILURE = 'MOVE_ISSUE_FAILURE';
+export const MOVE_EPIC = 'MOVE_EPIC';
+export const MOVE_EPIC_FAILURE = 'MOVE_EPIC_FAILURE';
 export const CREATE_LIST_FAILURE = 'CREATE_LIST_FAILURE';
 export const SET_BOARD_EPIC_USER_PREFERENCES = 'SET_BOARD_EPIC_USER_PREFERENCES';
 export const RECEIVE_MILESTONES_REQUEST = 'RECEIVE_MILESTONES_REQUEST';

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

 import { union, unionBy } from 'lodash';
 import Vue from 'vue';
-import { moveIssueListHelper } from '~/boards/boards_util';
+import { moveItemListHelper } from '~/boards/boards_util';
 import { issuableTypes } from '~/boards/constants';
-import mutationsCE, { addIssueToList, removeIssueFromList } from '~/boards/stores/mutations';
+import mutationsCE, { addItemToList, removeItemFromList } from '~/boards/stores/mutations';
 import { s__, __ } from '~/locale';
 import { ErrorMessages } from '../constants';
 import * as mutationTypes from './mutation_types';
@@ -168,7 +168,7 @@ export default {
     const fromList = state.boardLists[fromListId];
     const toList = state.boardLists[toListId];
 
-    const issue = moveIssueListHelper(originalIssue, fromList, toList);
+    const issue = moveItemListHelper(originalIssue, fromList, toList);
 
     if (epicId === null) {
       Vue.set(state.boardItems, issue.id, { ...issue, epic: null });
@@ -176,8 +176,37 @@ export default {
       Vue.set(state.boardItems, issue.id, { ...issue, epic: { id: epicId } });
     }
 
-    removeIssueFromList({ state, listId: fromListId, issueId: issue.id });
-    addIssueToList({ state, listId: toListId, issueId: issue.id, moveBeforeId, moveAfterId });
+    removeItemFromList({ state, listId: fromListId, itemId: issue.id });
+    addItemToList({ state, listId: toListId, itemId: issue.id, moveBeforeId, moveAfterId });
+  },
+
+  [mutationTypes.MOVE_EPIC]: (
+    state,
+    { originalEpic, fromListId, toListId, moveBeforeId, moveAfterId },
+  ) => {
+    const fromList = state.boardLists[fromListId];
+    const toList = state.boardLists[toListId];
+
+    const epic = moveItemListHelper(originalEpic, fromList, toList);
+    Vue.set(state.boardItems, epic.id, epic);
+
+    removeItemFromList({ state, listId: fromListId, itemId: epic.id });
+    addItemToList({ state, listId: toListId, itemId: epic.id, moveBeforeId, moveAfterId });
+  },
+
+  [mutationTypes.MOVE_EPIC_FAILURE]: (
+    state,
+    { originalEpic, fromListId, toListId, originalIndex },
+  ) => {
+    state.error = s__('Boards|An error occurred while moving the epic. Please try again.');
+    Vue.set(state.boardItems, originalEpic.id, originalEpic);
+    removeItemFromList({ state, listId: toListId, itemId: originalEpic.id });
+    addItemToList({
+      state,
+      listId: fromListId,
+      itemId: originalEpic.id,
+      atIndex: originalIndex,
+    });
   },
 
   [mutationTypes.SET_BOARD_EPIC_USER_PREFERENCES]: (state, val) => {

ee/spec/features/epic_boards/epic_boards_spec.rb

@@ -3,6 +3,9 @@
 require 'spec_helper'
 
 RSpec.describe 'epic boards', :js do
+  include DragTo
+  include MobileHelpers
+
   let_it_be(:user) { create(:user) }
   let_it_be(:group) { create(:group, :public) }
 
@@ -63,7 +66,7 @@ RSpec.describe 'epic boards', :js do
       end
     end
 
-    it 'creates new column for label containing labeled issue' do
+    it 'creates new column for label containing labeled epic' do
       click_button 'Create list'
       wait_for_all_requests
 
@@ -77,6 +80,16 @@ RSpec.describe 'epic boards', :js do
       expect(page).to have_selector('.board', text: label2.title)
       expect(find('.board:nth-child(3) .board-card')).to have_content(epic3.title)
     end
+
+    it 'moves epic between lists' do
+      expect(find('.board:nth-child(1)')).to have_content(epic3.title)
+
+      drag(list_from_index: 0, list_to_index: 1)
+      wait_for_all_requests
+
+      expect(find('.board:nth-child(1)')).not_to have_content(epic3.title)
+      expect(find('.board:nth-child(2)')).to have_content(epic3.title)
+    end
   end
 
   context 'when user can admin epic boards' do
@@ -113,4 +126,17 @@ RSpec.describe 'epic boards', :js do
   def list_header(list)
     find(".board[data-id='gid://gitlab/Boards::EpicList/#{list.id}'] .board-header")
   end
+
+  def drag(selector: '.board-list', list_from_index: 0, from_index: 0, to_index: 0, list_to_index: 0, perform_drop: true)
+    # ensure there is enough horizontal space for four lists
+    resize_window(2000, 800)
+
+    drag_to(selector: selector,
+            scrollable: '#board-app',
+            list_from_index: list_from_index,
+            from_index: from_index,
+            to_index: to_index,
+            list_to_index: list_to_index,
+            perform_drop: perform_drop)
+  end
 end

ee/spec/frontend/boards/mock_data.js

@@ -216,6 +216,7 @@ export const mockEpic = {
     closedIssues: 2,
   },
   issues: [mockIssue],
+  labels: [],
 };
 
 export const mockIssueWithEpic = { ...mockIssue3, epic: { id: mockEpic.id, iid: mockEpic.iid } };
@@ -238,6 +239,7 @@ export const mockEpics = [
     parent: {
       id: '40',
     },
+    labels: [],
   },
   {
     id: 'gid://gitlab/Epic/40',
@@ -252,6 +254,7 @@ export const mockEpics = [
     web_url: '/groups/gitlab-org/marketing/-/epics/1',
     descendantCounts: defaultDescendantCounts,
     hasParent: false,
+    labels: [],
   },
   {
     id: 'gid://gitlab/Epic/39',
@@ -266,6 +269,7 @@ export const mockEpics = [
     web_url: '/groups/gitlab-org/-/epics/12',
     descendantCounts: defaultDescendantCounts,
     hasParent: false,
+    labels: [],
   },
   {
     id: 'gid://gitlab/Epic/38',
@@ -280,6 +284,7 @@ export const mockEpics = [
     web_url: '/groups/gitlab-org/-/epics/11',
     descendantCounts: defaultDescendantCounts,
     hasParent: false,
+    labels: [],
   },
   {
     id: 'gid://gitlab/Epic/37',
@@ -294,6 +299,7 @@ export const mockEpics = [
     web_url: '/groups/gitlab-org/-/epics/10',
     descendantCounts: defaultDescendantCounts,
     hasParent: false,
+    labels: [],
   },
 ];
 

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

@@ -14,7 +14,15 @@ import { issuableTypes } from '~/boards/constants';
 import * as typesCE from '~/boards/stores/mutation_types';
 import * as commonUtils from '~/lib/utils/common_utils';
 import { mergeUrlParams, removeParams } from '~/lib/utils/url_utility';
-import { mockLists, mockIssue, mockIssue2, mockEpic, rawIssue, mockMilestones } from '../mock_data';
+import {
+  mockLists,
+  mockIssue,
+  mockIssue2,
+  mockEpic,
+  mockEpics,
+  rawIssue,
+  mockMilestones,
+} from '../mock_data';
 
 Vue.use(Vuex);
 
@@ -846,6 +854,21 @@ describe('setActiveIssueWeight', () => {
   });
 });
 
+describe.each`
+  isEpicBoard | issuableType             | dispatchedAction
+  ${false}    | ${'issuableTypes.issue'} | ${'moveIssue'}
+  ${true}     | ${'issuableTypes.epic'}  | ${'moveEpic'}
+`('moveItem', ({ isEpicBoard, issuableType, dispatchedAction }) => {
+  it(`should dispatch ${dispatchedAction}  action when isEpicBoard is ${isEpicBoard}`, async () => {
+    await testAction({
+      action: actions.moveItem,
+      payload: { itemId: 1 },
+      state: { isEpicBoard, issuableType },
+      expectedActions: [{ type: dispatchedAction, payload: { itemId: 1 } }],
+    });
+  });
+});
+
 describe('moveIssue', () => {
   const epicId = 'gid://gitlab/Epic/1';
 
@@ -882,9 +905,9 @@ describe('moveIssue', () => {
     testAction(
       actions.moveIssue,
       {
-        issueId: '436',
-        issueIid: mockIssue.iid,
-        issuePath: mockIssue.referencePath,
+        itemId: '436',
+        itemIid: mockIssue.iid,
+        itemPath: mockIssue.referencePath,
         fromListId: 'gid://gitlab/List/1',
         toListId: 'gid://gitlab/List/2',
         epicId,
@@ -923,9 +946,9 @@ describe('moveIssue', () => {
     testAction(
       actions.moveIssue,
       {
-        issueId: '436',
-        issueIid: mockIssue.iid,
-        issuePath: mockIssue.referencePath,
+        itemId: '436',
+        itemIid: mockIssue.iid,
+        itemPath: mockIssue.referencePath,
         fromListId: 'gid://gitlab/List/1',
         toListId: 'gid://gitlab/List/2',
         epicId,
@@ -955,12 +978,105 @@ describe('moveIssue', () => {
       done,
     );
   });
+});
+
+describe('moveEpic', () => {
+  const listEpics = {
+    'gid://gitlab/List/1': [41, 40],
+    'gid://gitlab/List/2': [],
+  };
 
-  describe.each`
+  const epics = {
+    41: mockEpic,
+    40: mockEpics[1],
+  };
+
+  const state = {
+    fullPath: 'gitlab-org',
+    boardId: 1,
+    boardType: 'group',
+    disabled: false,
+    boardLists: mockLists,
+    boardItemsByListId: listEpics,
+    boardItems: epics,
+    issuableType: 'epic',
+  };
+
+  it('should commit MOVE_EPIC mutation mutation when successful', async () => {
+    jest.spyOn(gqlClient, 'mutate').mockResolvedValue({
+      data: {
+        epicMoveList: {
+          errors: [],
+        },
+      },
+    });
+
+    await testAction({
+      action: actions.moveEpic,
+      payload: {
+        itemId: '41',
+        fromListId: 'gid://gitlab/List/1',
+        toListId: 'gid://gitlab/List/2',
+      },
+      state,
+      expectedMutations: [
+        {
+          type: types.MOVE_EPIC,
+          payload: {
+            originalEpic: mockEpic,
+            fromListId: 'gid://gitlab/List/1',
+            toListId: 'gid://gitlab/List/2',
+          },
+        },
+      ],
+    });
+  });
+
+  it('should commit MOVE_EPIC mutation and MOVE_EPIC_FAILURE mutation when unsuccessful', async () => {
+    jest.spyOn(gqlClient, 'mutate').mockResolvedValue({
+      data: {
+        epicMoveList: {
+          errors: [{ foo: 'bar' }],
+        },
+      },
+    });
+
+    await testAction({
+      action: actions.moveEpic,
+      payload: {
+        itemId: '41',
+        fromListId: 'gid://gitlab/List/1',
+        toListId: 'gid://gitlab/List/2',
+      },
+      state,
+      expectedMutations: [
+        {
+          type: types.MOVE_EPIC,
+          payload: {
+            originalEpic: mockEpic,
+            fromListId: 'gid://gitlab/List/1',
+            toListId: 'gid://gitlab/List/2',
+          },
+        },
+        {
+          type: types.MOVE_EPIC_FAILURE,
+          payload: {
+            originalEpic: mockEpic,
+            fromListId: 'gid://gitlab/List/1',
+            toListId: 'gid://gitlab/List/2',
+            originalIndex: 0,
+          },
+        },
+      ],
+    });
+  });
+});
+
+describe.each`
   isEpicBoard | issuableType             | dispatchedAction
   ${false}    | ${'issuableTypes.issue'} | ${'createIssueList'}
   ${true}     | ${'issuableTypes.epic'}  | ${'createEpicList'}
-  `('createList', ({ isEpicBoard, issuableType, dispatchedAction }) => {
+`('createList', ({ isEpicBoard, issuableType, dispatchedAction }) => {
   it(`should dispatch ${dispatchedAction}  action when isEpicBoard is ${isEpicBoard}`, async () => {
     await testAction({
       action: actions.createList,
@@ -969,13 +1085,21 @@ describe('moveIssue', () => {
       expectedActions: [{ type: dispatchedAction, payload: { backlog: true } }],
     });
   });
-  });
+});
 
-  describe('createEpicList', () => {
+describe('createEpicList', () => {
   let commit;
   let dispatch;
   let getters;
 
+  const state = {
+    fullPath: 'gitlab-org',
+    boardId: 1,
+    boardType: 'group',
+    disabled: false,
+    boardLists: mockLists,
+  };
+
   beforeEach(() => {
     commit = jest.fn();
     dispatch = jest.fn();
@@ -1062,7 +1186,6 @@ describe('moveIssue', () => {
     expect(dispatch).toHaveBeenCalledTimes(1);
     expect(commit).not.toHaveBeenCalled();
   });
-  });
 });
 
 describe('fetchMilestones', () => {

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

@@ -327,6 +327,40 @@ describe('MOVE_ISSUE', () => {
   });
 });
 
+describe('MOVE_EPIC', () => {
+  it('updates boardItemsByListId, moving epic between lists', () => {
+    const listIssues = {
+      'gid://gitlab/List/1': [mockEpic.id, mockEpics[1].id],
+      'gid://gitlab/List/2': [],
+    };
+
+    const epics = {
+      1: mockEpic,
+      2: mockEpics[1],
+    };
+
+    state = {
+      ...state,
+      boardItemsByListId: listIssues,
+      boardLists: initialBoardListsState,
+      boardItems: epics,
+    };
+
+    mutations.MOVE_EPIC(state, {
+      originalEpic: mockEpics[1],
+      fromListId: 'gid://gitlab/List/1',
+      toListId: 'gid://gitlab/List/2',
+    });
+
+    const updatedListEpics = {
+      'gid://gitlab/List/1': [mockEpic.id],
+      'gid://gitlab/List/2': [mockEpics[1].id],
+    };
+
+    expect(state.boardItemsByListId).toEqual(updatedListEpics);
+  });
+});
+
 describe('SET_BOARD_EPIC_USER_PREFERENCES', () => {
   it('should replace userPreferences on the given epic', () => {
     state = {

locale/gitlab.pot

@@ -4872,6 +4872,9 @@ msgstr ""
 msgid "Boards|An error occurred while generating lists. Please reload the page."
 msgstr ""
 
+msgid "Boards|An error occurred while moving the epic. Please try again."
+msgstr ""
+
 msgid "Boards|An error occurred while moving the issue. Please try again."
 msgstr ""
 

spec/frontend/boards/board_list_spec.js

@@ -125,7 +125,7 @@ describe('Board list component', () => {
     });
 
     it('sets data attribute with issue id', () => {
-      expect(wrapper.find('.board-card').attributes('data-issue-id')).toBe('1');
+      expect(wrapper.find('.board-card').attributes('data-item-id')).toBe('1');
     });
 
     it('shows new issue form', async () => {
@@ -258,7 +258,7 @@ describe('Board list component', () => {
 
     describe('handleDragOnEnd', () => {
       it('removes class `is-dragging` from document body', () => {
-        jest.spyOn(wrapper.vm, 'moveIssue').mockImplementation(() => {});
+        jest.spyOn(wrapper.vm, 'moveItem').mockImplementation(() => {});
         document.body.classList.add('is-dragging');
 
         findByTestId('tree-root-wrapper').vm.$emit('end', {
@@ -266,9 +266,9 @@ describe('Board list component', () => {
           newIndex: 0,
           item: {
             dataset: {
-              issueId: mockIssues[0].id,
-              issueIid: mockIssues[0].iid,
-              issuePath: mockIssues[0].referencePath,
+              itemId: mockIssues[0].id,
+              itemIid: mockIssues[0].iid,
+              itemPath: mockIssues[0].referencePath,
             },
           },
           to: { children: [], dataset: { listId: 'gid://gitlab/List/1' } },

spec/frontend/boards/components/board_card_spec.js

@@ -6,7 +6,7 @@ import BoardCardInner from '~/boards/components/board_card_inner.vue';
 import { inactiveId } from '~/boards/constants';
 import { mockLabelList, mockIssue } from '../mock_data';
 
-describe('Board card layout', () => {
+describe('Board card', () => {
   let wrapper;
   let store;
   let mockActions;
@@ -44,7 +44,7 @@ describe('Board card layout', () => {
       store,
       propsData: {
         list: mockLabelList,
-        issue: mockIssue,
+        item: mockIssue,
         disabled: false,
         index: 0,
         ...propsData,
@@ -113,7 +113,7 @@ describe('Board card layout', () => {
       expect(wrapper.classes()).not.toContain('is-active');
     });
 
-    describe('when mouseup event is called on the issue card', () => {
+    describe('when mouseup event is called on the card', () => {
       beforeEach(() => {
         createStore({ isSwimlanesOn });
         mountComponent();

spec/frontend/boards/stores/actions_spec.js

@@ -637,6 +637,15 @@ describe('resetIssues', () => {
   });
 });
 
+describe('moveItem', () => {
+  it('should dispatch moveIssue action', () => {
+    testAction({
+      action: actions.moveItem,
+      expectedActions: [{ type: 'moveIssue' }],
+    });
+  });
+});
+
 describe('moveIssue', () => {
   const listIssues = {
     'gid://gitlab/List/1': [436, 437],
@@ -671,9 +680,9 @@ describe('moveIssue', () => {
     testAction(
       actions.moveIssue,
       {
-        issueId: '436',
-        issueIid: mockIssue.iid,
-        issuePath: mockIssue.referencePath,
+        itemId: '436',
+        itemIid: mockIssue.iid,
+        itemPath: mockIssue.referencePath,
         fromListId: 'gid://gitlab/List/1',
         toListId: 'gid://gitlab/List/2',
       },
@@ -722,9 +731,9 @@ describe('moveIssue', () => {
     actions.moveIssue(
       { state, commit: () => {} },
       {
-        issueId: mockIssue.id,
-        issueIid: mockIssue.iid,
-        issuePath: mockIssue.referencePath,
+        itemId: mockIssue.id,
+        itemIid: mockIssue.iid,
+        itemPath: mockIssue.referencePath,
         fromListId: 'gid://gitlab/List/1',
         toListId: 'gid://gitlab/List/2',
       },
@@ -746,9 +755,9 @@ describe('moveIssue', () => {
     testAction(
       actions.moveIssue,
       {
-        issueId: '436',
-        issueIid: mockIssue.iid,
-        issuePath: mockIssue.referencePath,
+        itemId: '436',
+        itemIid: mockIssue.iid,
+        itemPath: mockIssue.referencePath,
         fromListId: 'gid://gitlab/List/1',
         toListId: 'gid://gitlab/List/2',
       },