refactor(Project): split out components into their own files

frontend/src/shared/hooks/useStateWithLocalStorage.ts

@@ -0,0 +1,13 @@
+import React from 'react';
+
+const useStateWithLocalStorage = (localStorageKey: string): [string, React.Dispatch<React.SetStateAction<string>>] => {
+  const [value, setValue] = React.useState<string>(localStorage.getItem(localStorageKey) || '');
+
+  React.useEffect(() => {
+    localStorage.setItem(localStorageKey, value);
+  }, [value]);
+
+  return [value, setValue];
+};
+
+export default useStateWithLocalStorage;

frontend/src/shared/utils/email.ts

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+const RFC2822_EMAIL = /[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/;
+
+export default function isValidEmail(target: string) {
+  return RFC2822_EMAIL.test(target);
+}

frontend/src/shared/utils/localStorage.ts

@@ -0,0 +1,5 @@
+const localStorage = {
+  CARD_LABEL_VARIANT_STORAGE_KEY: 'card_label_variant',
+};
+
+export default localStorage;