Use immer

client/src/js/state/input.js

@@ -1,54 +1,45 @@
-import { List, Record } from 'immutable';
 import createReducer from 'utils/createReducer';
 import * as actions from './actions';
 
 const HISTORY_MAX_LENGTH = 128;
 
-const State = Record({
-  history: List(),
+const initialState = {
+  history: [],
   index: 0
-});
+};
 
 export const getCurrentInputHistoryEntry = state => {
   if (state.input.index === -1) {
     return null;
   }
 
-  return state.input.history.get(state.input.index);
+  return state.input.history[state.input.index];
 };
 
-export default createReducer(new State(), {
-  [actions.INPUT_HISTORY_ADD](state, action) {
-    const { line } = action;
-    if (line.trim() && line !== state.history.get(0)) {
+export default createReducer(initialState, {
+  [actions.INPUT_HISTORY_ADD](state, { line }) {
+    if (line.trim() && line !== state.history[0]) {
       if (history.length === HISTORY_MAX_LENGTH) {
-        return state.set('history', state.history.unshift(line).pop());
+        state.history.pop();
       }
-
-      return state.set('history', state.history.unshift(line));
+      state.history.unshift(line);
     }
-
-    return state;
   },
 
   [actions.INPUT_HISTORY_RESET](state) {
-    return state.set('index', -1);
+    state.index = -1;
   },
 
   [actions.INPUT_HISTORY_INCREMENT](state) {
-    if (state.index < state.history.size - 1) {
-      return state.set('index', state.index + 1);
+    if (state.index < state.history.length - 1) {
+      state.index++;
     }
-
-    return state;
   },
 
   [actions.INPUT_HISTORY_DECREMENT](state) {
     if (state.index >= 0) {
-      return state.set('index', state.index - 1);
+      state.index--;
     }
-
-    return state;
   }
 });