refactor(theme-search-algolia): migrate package to TS (#5935)

packages/docusaurus-theme-search-algolia/src/theme/hooks/useSearchQuery.ts

@@ -0,0 +1,64 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {useHistory} from '@docusaurus/router';
+import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import {useCallback, useEffect, useState} from 'react';
+import type {SearchQuery} from '@theme/hooks/useSearchQuery';
+
+const SEARCH_PARAM_QUERY = 'q';
+
+function useSearchQuery(): SearchQuery {
+  const history = useHistory();
+  const {
+    siteConfig: {baseUrl},
+  } = useDocusaurusContext();
+
+  const [searchQuery, setSearchQueryState] = useState('');
+
+  // Init search query just after React hydration
+  useEffect(() => {
+    const searchQueryStringValue =
+      new URLSearchParams(window.location.search).get(SEARCH_PARAM_QUERY) ?? '';
+
+    setSearchQueryState(searchQueryStringValue);
+  }, []);
+
+  const setSearchQuery = useCallback(
+    (newSearchQuery: string) => {
+      const searchParams = new URLSearchParams(window.location.search);
+
+      if (newSearchQuery) {
+        searchParams.set(SEARCH_PARAM_QUERY, newSearchQuery);
+      } else {
+        searchParams.delete(SEARCH_PARAM_QUERY);
+      }
+
+      history.replace({
+        search: searchParams.toString(),
+      });
+      setSearchQueryState(newSearchQuery);
+    },
+    [history],
+  );
+
+  const generateSearchPageLink = useCallback(
+    (targetSearchQuery: string) => {
+      // Refer to https://github.com/facebook/docusaurus/pull/2838
+      return `${baseUrl}search?q=${encodeURIComponent(targetSearchQuery)}`;
+    },
+    [baseUrl],
+  );
+
+  return {
+    searchQuery,
+    setSearchQuery,
+    generateSearchPageLink,
+  };
+}
+
+export default useSearchQuery;