Undo/redo (#659)

* immutable crossfilter

* first cut at reducer refactor with cascade model

* add initial redo/undo implementation

* small optimization

* integrate expression with history

* add tests for new reducers and fix a couple of small initialization bugs

* treat tiny lasso selections as a clear

* better function name for clarity

* fix undo for differential expression

* remove logging

* fix regression due to bad merge

* cleanup and comments for clarity

* improve undoable configuration for flexibility

* fix stale comments

* remove debugging code from production build

* rename categoricalSelectionState

* rename file

* improve comments

client/src/reducers/index.js

@@ -1,20 +1,86 @@
-// jshint esversion: 6
-import { combineReducers, createStore, applyMiddleware } from "redux";
+import { createStore, applyMiddleware } from "redux";
 import thunk from "redux-thunk";
-import { composeWithDevTools } from "redux-devtools-extension";
 
+import cascadeReducers from "./cascade";
+import undoable from "./undoable";
 import config from "./config";
+import universe from "./universe";
+import world from "./world";
+import categoricalSelection from "./categoricalSelection";
+import crossfilter from "./crossfilter";
+import colors from "./colors";
 import differential from "./differential";
 import responsive from "./responsive";
 import controls from "./controls";
+import resetCache from "./resetCache";
 
-const Reducer = combineReducers({
-  config,
-  responsive,
-  controls,
-  differential
-});
+const ignoredActions = new Set([
+  // these actions will not affect history, ie, we will
+  // not snapshot history upon these actions.  These take
+  // precedent over `clearHistoryUponActions`
+  "url changed",
+  "interface reset started",
+  "initial data load start",
+  "configuration load complete",
+  "increment graph render counter",
+  "window resize",
 
-const store = createStore(Reducer, composeWithDevTools(applyMiddleware(thunk)));
+  "lasso started",
+
+  "request differential expression success",
+
+  "expression load start",
+  "expression load success",
+  "expression load error",
+
+  "continuous metadata histogram brush",
+  "continuous metadata histogram end",
+
+  "request user defined gene started",
+  "request user defined gene success",
+  "request user defined gene error",
+  "bulk user defined gene complete",
+  "single user defined gene complete"
+]);
+
+const clearOnActions = new Set([
+  // history will be cleared when these actions occur
+  "initial data load complete (universe exists)",
+  "reset World to eq Universe",
+  "initial data load error"
+]);
+
+/* configuration for the undoable meta reducer */
+const undoableConfig = {
+  historyLimit: 50, // maximum history size
+  skipActionFilter: (state, action) => ignoredActions.has(action.type),
+  clearOnActionFilter: (state, action) => clearOnActions.has(action.type)
+};
+
+const Reducer = undoable(
+  cascadeReducers([
+    ["config", config],
+    ["universe", universe],
+    ["world", world],
+    ["categoricalSelection", categoricalSelection],
+    ["crossfilter", crossfilter],
+    ["colors", colors],
+    ["controls", controls],
+    ["differential", differential],
+    ["responsive", responsive],
+    ["resetCache", resetCache]
+  ]),
+  [
+    "world",
+    "categoricalSelection",
+    "crossfilter",
+    "colors",
+    "controls",
+    "differential"
+  ],
+  undoableConfig
+);
+
+const store = createStore(Reducer, applyMiddleware(thunk));
 
 export default store;