Merge pull request #28 from VKCOM/add-funcs

Add functions

src/async.ts

@@ -0,0 +1,26 @@
+/**
+ * Loads async import with retries. It can be useful for bad internet connection
+ *
+ * @example
+ * const HeaderLazyComponent = React.lazy(() => asyncImportLoader(() => import('../components/Header/Header')));
+ *
+ * @example
+ * asyncImportLoader(() => import('some-module'), 20).then((someModule) => {
+ *   someModule.init();
+ * });
+ */
+export const asyncImportLoader = <T>(asyncImport: () => Promise<T>, attempts = 10): Promise<T> => {
+  return new Promise((resolve, reject) => {
+    asyncImport()
+      .then(resolve)
+      .catch((error) => {
+        setTimeout(() => {
+          if (attempts === 0) {
+            reject(error);
+            return;
+          }
+          asyncImportLoader(asyncImport, attempts - 1).then(resolve, reject);
+        }, 1000);
+      });
+  });
+};

src/index.ts

@@ -54,6 +54,10 @@ export {
   difference,
 } from './arrays';
 
+export {
+  asyncImportLoader,
+} from './async';
+
 export {
   getCookie,
 } from './cookie';
@@ -142,6 +146,10 @@ export type {
   Writeable,
 } from './types';
 
+export {
+  escapeRegExp,
+} from './regexp';
+
 export {
   localStorage,
   sessionStorage,

src/regexp.ts

@@ -0,0 +1,13 @@
+/**
+ * Escapes a string so that it can be put into RegExp as a variable
+ *
+ * @example
+ * new RegExp(`foo-${escapeRegExp('(bar)')}`, 'i')
+ */
+export function escapeRegExp(string: string): string {
+  if (string) {
+    return string.replace(/([.*+?^${}()|[\]\/\\])/g, '\\$1');
+  }
+
+  return '';
+}