Swimlanes - Paginate epics

Chain fetch epics by chunks of 20

app/assets/javascripts/boards/index.js

@@ -155,7 +155,13 @@ export default () => {
       }
     },
     methods: {
-      ...mapActions(['setInitialBoardData', 'setFilters', 'fetchEpicsSwimlanes', 'resetIssues']),
+      ...mapActions([
+        'setInitialBoardData',
+        'setFilters',
+        'fetchEpicsSwimlanes',
+        'resetIssues',
+        'resetEpics',
+      ]),
       initialBoardLoad() {
         boardsStore
           .all()
@@ -176,7 +182,8 @@ export default () => {
       performSearch() {
         this.setFilters(convertObjectPropsToCamelCase(urlParamsToObject(window.location.search)));
         if (gon.features.boardsWithSwimlanes && this.isShowingEpicsSwimlanes) {
-          this.fetchEpicsSwimlanes(false);
+          this.resetEpics();
+          this.fetchEpicsSwimlanes({ withLists: false });
           this.resetIssues();
         }
       },

ee/app/assets/javascripts/boards/queries/epics_swimlanes.query.graphql

@@ -8,6 +8,7 @@ query BoardEE(
   $withLists: Boolean = true
   $isGroup: Boolean = false
   $isProject: Boolean = false
+  $after: String
 ) {
   group(fullPath: $fullPath) @include(if: $isGroup) {
     board(id: $boardId) {
@@ -16,9 +17,15 @@ query BoardEE(
           ...BoardListFragment
         }
       }
-      epics(issueFilters: $issueFilters) {
-        nodes {
-          ...BoardEpicNode
+      epics(first: 2, issueFilters: $issueFilters, after: $after) {
+        edges {
+          node {
+            ...BoardEpicNode
+          }
+        }
+        pageInfo {
+          endCursor
+          hasNextPage
         }
       }
     }
@@ -30,9 +37,15 @@ query BoardEE(
           ...BoardListFragment
         }
       }
-      epics(issueFilters: $issueFilters) {
-        nodes {
-          ...BoardEpicNode
+      epics(first: 20, issueFilters: $issueFilters, after: $after) {
+        edges {
+          node {
+            ...BoardEpicNode
+          }
+        }
+        pageInfo {
+          endCursor
+          hasNextPage
         }
       }
     }

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

@@ -75,7 +75,7 @@ export default {
     commit(types.SET_FILTERS, filterParams);
   },
 
-  fetchEpicsSwimlanes({ state, commit }, withLists = true) {
+  fetchEpicsSwimlanes({ state, commit, dispatch }, { withLists = true, endCursor = null }) {
     const { endpoints, boardType, filterParams } = state;
     const { fullPath, boardId } = endpoints;
 
@@ -86,6 +86,7 @@ export default {
       withLists,
       isGroup: boardType === BoardType.group,
       isProject: boardType === BoardType.project,
+      after: endCursor,
     };
 
     return gqlClient
@@ -95,24 +96,27 @@ export default {
       })
       .then(({ data }) => {
         const { epics, lists } = data[boardType]?.board;
-        const epicsFormatted = epics.nodes.map(e => ({
-          ...e,
-          issues: (e?.issues?.nodes || []).map(i => ({
-            ...i,
-            labels: i.labels?.nodes || [],
-            assignees: i.assignees?.nodes || [],
-          })),
+        const epicsFormatted = epics.edges.map(e => ({
+          ...e.node,
         }));
 
         if (!withLists) {
           commit(types.RECEIVE_EPICS_SUCCESS, epicsFormatted);
         }
 
+        if (epics.pageInfo?.hasNextPage) {
+          dispatch('fetchEpicsSwimlanes', {
+            withLists: false,
+            endCursor: epics.pageInfo.endCursor,
+          });
+        }
+
         return {
           epics: epicsFormatted,
           lists: lists?.nodes,
         };
-      });
+      })
+      .catch(() => commit(types.RECEIVE_SWIMLANES_FAILURE));
   },
 
   setShowLabels({ commit }, val) {
@@ -206,7 +210,7 @@ export default {
     commit(types.TOGGLE_EPICS_SWIMLANES);
 
     if (state.isShowingEpicsSwimlanes) {
-      dispatch('fetchEpicsSwimlanes')
+      dispatch('fetchEpicsSwimlanes', {})
         .then(({ lists, epics }) => {
           if (lists) {
             let boardLists = lists.map(list =>
@@ -226,4 +230,8 @@ export default {
       eventHub.$emit('initialBoardLoad');
     }
   },
+
+  resetEpics: ({ commit }) => {
+    commit(types.RESET_EPICS);
+  },
 };

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

@@ -20,5 +20,6 @@ export const TOGGLE_EPICS_SWIMLANES = 'TOGGLE_EPICS_SWIMLANES';
 export const RECEIVE_BOARD_LISTS_SUCCESS = 'RECEIVE_BOARD_LISTS_SUCCESS';
 export const RECEIVE_SWIMLANES_FAILURE = 'RECEIVE_SWIMLANES_FAILURE';
 export const RECEIVE_EPICS_SUCCESS = 'RECEIVE_EPICS_SUCCESS';
+export const RESET_EPICS = 'RESET_EPICS';
 export const SET_SHOW_LABELS = 'SET_SHOW_LABELS';
 export const SET_FILTERS = 'SET_FILTERS';

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

@@ -103,6 +103,10 @@ export default {
   },
 
   [mutationTypes.RECEIVE_EPICS_SUCCESS]: (state, epics) => {
-    state.epics = epics;
+    Vue.set(state, 'epics', union(state.epics || [], epics));
+  },
+
+  [mutationTypes.RESET_EPICS]: state => {
+    Vue.set(state, 'epics', []);
   },
 };

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

@@ -5,6 +5,6 @@ export default () => ({
 
   isShowingEpicsSwimlanes: false,
   epicsSwimlanesFetchInProgress: false,
-  epics: {},
+  epics: [],
   epicsFlags: {},
 });

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

@@ -63,6 +63,99 @@ describe('setFilters', () => {
   });
 });
 
+describe('fetchEpicsSwimlanes', () => {
+  const state = {
+    endpoints: {
+      fullPath: 'gitlab-org',
+      boardId: 1,
+    },
+    filterParams: {},
+    boardType: 'group',
+  };
+
+  const queryResponse = {
+    data: {
+      group: {
+        board: {
+          epics: {
+            edges: [{ node: mockEpic }],
+            pageInfo: {},
+          },
+        },
+      },
+    },
+  };
+
+  it('should commit mutation RECEIVE_EPICS_SUCCESS on success without lists', done => {
+    jest.spyOn(gqlClient, 'query').mockResolvedValue(queryResponse);
+
+    testAction(
+      actions.fetchEpicsSwimlanes,
+      { withLists: false },
+      state,
+      [
+        {
+          type: types.RECEIVE_EPICS_SUCCESS,
+          payload: [mockEpic],
+        },
+      ],
+      [],
+      done,
+    );
+  });
+
+  it('should commit mutation RECEIVE_SWIMLANES_FAILURE on failure', done => {
+    jest.spyOn(gqlClient, 'query').mockResolvedValue(Promise.reject());
+
+    testAction(
+      actions.fetchEpicsSwimlanes,
+      {},
+      state,
+      [{ type: types.RECEIVE_SWIMLANES_FAILURE }],
+      [],
+      done,
+    );
+  });
+
+  it('should dispatch fetchEpicsSwimlanes when page info hasNextPage', done => {
+    const queryResponseWithNextPage = {
+      data: {
+        group: {
+          board: {
+            epics: {
+              edges: [{ node: mockEpic }],
+              pageInfo: {
+                hasNextPage: true,
+                endCursor: 'ENDCURSOR',
+              },
+            },
+          },
+        },
+      },
+    };
+    jest.spyOn(gqlClient, 'query').mockResolvedValue(queryResponseWithNextPage);
+
+    testAction(
+      actions.fetchEpicsSwimlanes,
+      { withLists: false },
+      state,
+      [
+        {
+          type: types.RECEIVE_EPICS_SUCCESS,
+          payload: [mockEpic],
+        },
+      ],
+      [
+        {
+          type: 'fetchEpicsSwimlanes',
+          payload: { withLists: false, endCursor: 'ENDCURSOR' },
+        },
+      ],
+      done,
+    );
+  });
+});
+
 describe('setShowLabels', () => {
   it('should commit mutation SET_SHOW_LABELS', done => {
     const state = {
@@ -251,3 +344,9 @@ describe('toggleEpicSwimlanes', () => {
     );
   });
 });
+
+describe('resetEpics', () => {
+  it('commits RESET_EPICS mutation', () => {
+    return testAction(actions.resetEpics, {}, {}, [{ type: types.RESET_EPICS }], []);
+  });
+});

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

@@ -205,7 +205,7 @@ describe('RECEIVE_SWIMLANES_FAILURE', () => {
 });
 
 describe('RECEIVE_EPICS_SUCCESS', () => {
-  it('populates epics with payload and set epicsFlags loading to true', () => {
+  it('populates epics with payload', () => {
     state = {
       ...state,
       epics: {},
@@ -216,3 +216,16 @@ describe('RECEIVE_EPICS_SUCCESS', () => {
     expect(state.epics).toEqual(mockEpics);
   });
 });
+
+describe('RESET_EPICS', () => {
+  it('should remove issues from issuesByListId state', () => {
+    state = {
+      ...state,
+      epics: mockEpics,
+    };
+
+    mutations.RESET_EPICS(state);
+
+    expect(state.epics).toEqual([]);
+  });
+});