Type Redux store and middleware (#24843)

app/javascript/mastodon/store/middlewares/loading_bar.ts

@@ -0,0 +1,31 @@
+import { showLoading, hideLoading } from 'react-redux-loading-bar';
+import { Middleware } from 'redux';
+import { RootState } from '..';
+
+interface Config {
+  promiseTypeSuffixes?: string[]
+}
+
+const defaultTypeSuffixes: Config['promiseTypeSuffixes'] = ['PENDING', 'FULFILLED', 'REJECTED'];
+
+export  const loadingBarMiddleware = (config: Config = {}): Middleware<Record<string, never>, RootState> => {
+  const promiseTypeSuffixes = config.promiseTypeSuffixes || defaultTypeSuffixes;
+
+  return ({ dispatch }) => next => (action) => {
+    if (action.type && !action.skipLoading) {
+      const [PENDING, FULFILLED, REJECTED] = promiseTypeSuffixes;
+
+      const isPending = new RegExp(`${PENDING}$`, 'g');
+      const isFulfilled = new RegExp(`${FULFILLED}$`, 'g');
+      const isRejected = new RegExp(`${REJECTED}$`, 'g');
+
+      if (action.type.match(isPending)) {
+        dispatch(showLoading());
+      } else if (action.type.match(isFulfilled) || action.type.match(isRejected)) {
+        dispatch(hideLoading());
+      }
+    }
+
+    return next(action);
+  };
+};