test("Informs about disconnected kernels, allows reconnection", async () => {
   const state$ = {
     value: {
       core: stateModule.makeStateRecord({
         kernelRef: "fake",
         entities: stateModule.makeEntitiesRecord({
           contents: stateModule.makeContentsRecord({
             byRef: Immutable.Map({
               fakeContent: stateModule.makeNotebookContentRecord()
             })
           }),
           kernels: stateModule.makeKernelsRecord({
             byRef: Immutable.Map({
               fake: stateModule.makeRemoteKernelRecord({
                 channels: null,
                 status: "not connected"
               })
             })
           })
         })
       }),
       app: {
         notificationSystem: { addNotification: jest.fn() }
       }
     }
   };
   const action$ = ActionsObservable.of(
     actions.executeCell({ id: "first", contentRef: "fakeContentRef" })
   );
   const responses = await executeCellEpic(action$, state$)
     .pipe(toArray())
     .toPromise();
   expect(responses).toEqual([]);
 });

export function fixtureStore(config: JSONObject) {
  const dummyNotebook = buildFixtureNotebook(config);

  const frontendToShell = new Subject();
  const shellToFrontend = new Subject();
  const mockShell = Subject.create(frontendToShell, shellToFrontend);
  const channels = mockShell;

  const kernelRef = createKernelRef();
  const contentRef = createContentRef();

  const initialAppState: AppState = {
    core: makeStateRecord({
      kernelRef,
      entities: makeEntitiesRecord({
        contents: makeContentsRecord({
          byRef: Immutable.Map({
            [contentRef]: makeNotebookContentRecord({
              model: makeDocumentRecord({
                notebook: dummyNotebook,
                savedNotebook:
                  config && config.saved === true
                    ? dummyNotebook
                    : emptyNotebook,
                cellPagers: Immutable.Map(),
                cellFocused:
                  config && config.codeCellCount && config.codeCellCount > 1
                    ? dummyNotebook.get("cellOrder", Immutable.List()).get(1)
                    : null
              }),
              filepath:
                config && config.noFilename ? "" : "dummy-store-nb.ipynb"
            })
          })
        }),
        kernels: makeKernelsRecord({
          byRef: Immutable.Map({
            [kernelRef]: makeRemoteKernelRecord({
              channels,
              status: "not connected"
            })
          })
        })
      })
    }),
    app: makeAppRecord({
      notificationSystem: {
        addNotification: () => {} // most of the time you'll want to mock this
      },
      githubToken: "TOKEN"
    }),
    config: Immutable.Map({
      theme: "light"
    }),
    comms: makeCommsRecord()
  };

  return createStore(rootReducer, initialAppState as any);
}

  test("", async function() {
    const state$ = new StateObservable(new Subject<stateModule.AppState>(), {
      core: stateModule.makeStateRecord({
        kernelRef: "fake",
        entities: stateModule.makeEntitiesRecord({
          kernels: stateModule.makeKernelsRecord({
            byRef: Immutable.Map({
              fake: stateModule.makeRemoteKernelRecord({
                type: "websocket",
                channels: new Subject<any>(),
                kernelSpecName: "fancy",
                id: "0"
              })
            })
          })
        })
      }),
      app: stateModule.makeAppRecord({
        host: stateModule.makeJupyterHostRecord({
          type: "jupyter",
          token: "eh",
          basePath: "http://localhost:8888/"
        }),
        notificationSystem: { addNotification: jest.fn() }
      }),
      comms: stateModule.makeCommsRecord(),
      config: Immutable.Map({})
    });
    const action$ = ActionsObservable.of(
      actions.interruptKernel({ kernelRef: "fake" })
    );

    const responseActions = await coreEpics
      .interruptKernelEpic(action$, state$)
      .pipe(toArray())
      .toPromise();

    expect(responseActions).toEqual([
      {
        type: "INTERRUPT_KERNEL_SUCCESSFUL",
        payload: { kernelRef: "fake" }
      }
    ]);
  });

const byRef = (state = Map(), action: Action): Map<{}, {}> => {
  let typedAction;
  switch (action.type) {
    case actionTypes.SET_LANGUAGE_INFO:
      // TODO: Should the kernel hold language info?
      return state;
    case actionTypes.KILL_KERNEL_SUCCESSFUL:
      typedAction = action as actionTypes.KillKernelSuccessful;
      return state.setIn([typedAction.payload.kernelRef, "status"], "killed");
    case actionTypes.KILL_KERNEL_FAILED:
      typedAction = action as actionTypes.KillKernelFailed;
      return state.setIn(
        [typedAction.payload.kernelRef, "status"],
        "failed to kill"
      );
    case actionTypes.RESTART_KERNEL:
      typedAction = action as actionTypes.RestartKernel;
      return state.setIn(
        [typedAction.payload.kernelRef, "status"],
        "restarting"
      );
    case actionTypes.LAUNCH_KERNEL:
      typedAction = action as actionTypes.LaunchKernelAction;
      return state.set(
        typedAction.payload.kernelRef,
        makeKernelNotStartedRecord({
          status: "launching",
          kernelSpecName: typedAction.payload.kernelSpec.name
        })
      );
    case actionTypes.LAUNCH_KERNEL_BY_NAME:
      typedAction = action as actionTypes.LaunchKernelByNameAction;
      return state.set(
        typedAction.payload.kernelRef,
        makeKernelNotStartedRecord({
          status: "launching",
          kernelSpecName: typedAction.payload.kernelSpecName
        })
      );
    case actionTypes.CHANGE_KERNEL_BY_NAME:
      typedAction = action as actionTypes.ChangeKernelByName;
      return state.setIn(
        [typedAction.payload.oldKernelRef, "status"],
        "changing"
      );
    case actionTypes.SET_KERNEL_INFO:
      typedAction = action as actionTypes.SetKernelInfo;
      let codemirrorMode = typedAction.payload.info.codemirrorMode;
      // If the codemirror mode isn't set, fallback on the language name
      if (!codemirrorMode) {
        codemirrorMode = typedAction.payload.info.languageName;
      }
      switch (typeof codemirrorMode) {
        case "string":
          // already set as we want it
          break;
        case "object":
          codemirrorMode = Map(codemirrorMode as JSONObject);
          break;
        default:
          // any other case results in falling back to language name
          codemirrorMode = typedAction.payload.info.languageName;
      }

      const helpLinks = typedAction.payload.info.helpLinks
        ? List(
            (typedAction.payload.info.helpLinks as HelpLink[]).map(
              makeHelpLinkRecord
            )
          )
        : List();

      return state.setIn(
        [typedAction.payload.kernelRef, "info"],
        makeKernelInfoRecord(typedAction.payload.info).merge({
          helpLinks,
          codemirrorMode
        })
      );
    case actionTypes.SET_EXECUTION_STATE:
      typedAction = action as actionTypes.SetExecutionStateAction;
      return state.setIn(
        [typedAction.payload.kernelRef, "status"],
        typedAction.payload.kernelStatus
      );
    case actionTypes.LAUNCH_KERNEL_SUCCESSFUL:
      typedAction = action as actionTypes.NewKernelAction;
      switch (typedAction.payload.kernel.type) {
        case "zeromq":
          return state.set(
            typedAction.payload.kernelRef,
            makeLocalKernelRecord(typedAction.payload.kernel)
          );
        case "websocket":
          return state.set(
            typedAction.payload.kernelRef,
            makeRemoteKernelRecord(typedAction.payload.kernel)
          );
        default:
          throw new Error(
//.........这里部分代码省略.........