First Commit

job-tracker-ui/src/hooks/useCompanies.ts

@@ -0,0 +1,50 @@
+import { useEffect, useState } from "react";
+import { api } from "../api";
+import { Company } from "../types";
+
+let cachedCompanies: Company[] | null = null;
+let inflight: Promise<Company[]> | null = null;
+
+async function fetchCompanies(): Promise<Company[]> {
+  if (cachedCompanies) return cachedCompanies;
+  if (inflight) return inflight;
+
+  inflight = api
+    .get<Company[]>("/companies")
+    .then((r) => {
+      cachedCompanies = r.data;
+      return r.data;
+    })
+    .finally(() => {
+      inflight = null;
+    });
+
+  return inflight;
+}
+
+export function invalidateCompaniesCache() {
+  cachedCompanies = null;
+}
+
+export function useCompanies() {
+  const [companies, setCompanies] = useState<Company[]>(cachedCompanies ?? []);
+  const [loading, setLoading] = useState(!cachedCompanies);
+
+  useEffect(() => {
+    let mounted = true;
+    setLoading(!cachedCompanies);
+    fetchCompanies()
+      .then((c) => {
+        if (mounted) setCompanies(c);
+      })
+      .finally(() => {
+        if (mounted) setLoading(false);
+      });
+    return () => {
+      mounted = false;
+    };
+  }, []);
+
+  return { companies, loading };
+}
+

job-tracker-ui/src/hooks/useDebouncedValue.ts

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+import { useEffect, useState } from "react";
+
+export function useDebouncedValue<T>(value: T, delayMs: number): T {
+  const [debounced, setDebounced] = useState<T>(value);
+
+  useEffect(() => {
+    const t = window.setTimeout(() => setDebounced(value), delayMs);
+    return () => window.clearTimeout(t);
+  }, [value, delayMs]);
+
+  return debounced;
+}
+