[Glitch] Add ability to follow hashtags in web UI

app/javascript/flavours/glitch/reducers/index.js

@@ -41,6 +41,7 @@ import account_notes from './account_notes';
 import picture_in_picture from './picture_in_picture';
 import accounts_map from './accounts_map';
 import history from './history';
+import tags from './tags';
 
 const reducers = {
   announcements,
@@ -85,6 +86,7 @@ const reducers = {
   account_notes,
   picture_in_picture,
   history,
+  tags,
 };
 
 export default combineReducers(reducers);

app/javascript/flavours/glitch/reducers/tags.js

@@ -0,0 +1,25 @@
+import {
+  HASHTAG_FETCH_SUCCESS,
+  HASHTAG_FOLLOW_REQUEST,
+  HASHTAG_FOLLOW_FAIL,
+  HASHTAG_UNFOLLOW_REQUEST,
+  HASHTAG_UNFOLLOW_FAIL,
+} from 'mastodon/actions/tags';
+import { Map as ImmutableMap, fromJS } from 'immutable';
+
+const initialState = ImmutableMap();
+
+export default function tags(state = initialState, action) {
+  switch(action.type) {
+  case HASHTAG_FETCH_SUCCESS:
+    return state.set(action.name, fromJS(action.tag));
+  case HASHTAG_FOLLOW_REQUEST:
+  case HASHTAG_UNFOLLOW_FAIL:
+    return state.setIn([action.name, 'following'], true);
+  case HASHTAG_FOLLOW_FAIL:
+  case HASHTAG_UNFOLLOW_REQUEST:
+    return state.setIn([action.name, 'following'], false);
+  default:
+    return state;
+  }
+};