Feature(map): Filter challenges on Map

closes #9346

common/app/routes/challenges/redux/map-ui-saga.js

@@ -0,0 +1,34 @@
+import types from './types';
+import { initMap } from './actions';
+import { unfilterMapUi, applyFilterToMap } from '../utils';
+
+export default function mapUiSaga(actions$, getState) {
+  return actions$
+    .filter(({ type }) => (
+      type === types.updateFilter ||
+      type === types.clearFilter
+    ))
+    .debounce(250)
+    .map(({ payload: filter = '' }) => filter)
+    .distinctUntilChanged()
+    .map(filter => {
+      const { challengesApp: { mapUi = {} } } = getState();
+      let newMapUi;
+      if (filter.length <= 3) {
+        newMapUi = unfilterMapUi(mapUi);
+      } else {
+        const regexString = filter
+          // replace spaces with any key to match dashes
+          .replace(/ /g, '.')
+          // makes search more fuzzy (thanks @xRahul)
+          .split('')
+          .join('.*');
+        const filterRegex = new RegExp(regexString, 'i');
+        newMapUi = applyFilterToMap(mapUi, filterRegex);
+      }
+      if (!newMapUi || newMapUi === mapUi) {
+        return null;
+      }
+      return initMap(newMapUi);
+    });
+}