test: add TypeScript compiler validation tests for useRecentSearches

hooks/useRecentSearches.type-compiler.test.ts

@@ -0,0 +1,55 @@
+import { describe, it, expect, expectTypeOf } from 'vitest';
+import { useRecentSearches, STORAGE_KEY, MAX_SEARCHES } from './useRecentSearches';
+
+// Infer the hook's public API directly from its implementation.
+type UseRecentSearchesReturn = ReturnType<typeof useRecentSearches>;
+
+describe('useRecentSearches — TypeScript compiler validation & schema constraints', () => {
+  it('1. exposes STORAGE_KEY and MAX_SEARCHES with correct primitive types', () => {
+    expectTypeOf(STORAGE_KEY).toBeString();
+    expectTypeOf(MAX_SEARCHES).toBeNumber();
+
+    expect(typeof STORAGE_KEY).toBe('string');
+    expect(typeof MAX_SEARCHES).toBe('number');
+  });
+
+  it('2. useRecentSearches accepts no arguments', () => {
+    expectTypeOf(useRecentSearches).parameters.toEqualTypeOf<[]>();
+
+    expect(useRecentSearches.length).toBe(0);
+  });
+
+  it('3. returns the expected public API shape', () => {
+    expectTypeOf<UseRecentSearchesReturn>().toEqualTypeOf<{
+      searches: string[];
+      addSearch: (query: string) => void;
+      clearSearches: () => void;
+      removeSearch: (query: string) => void;
+    }>();
+
+    expectTypeOf<UseRecentSearchesReturn['searches']>().toEqualTypeOf<string[]>();
+  });
+
+  it('4. enforces function parameter and return types', () => {
+    expectTypeOf<UseRecentSearchesReturn['addSearch']>().parameters.toEqualTypeOf<[string]>();
+    expectTypeOf<UseRecentSearchesReturn['addSearch']>().returns.toBeVoid();
+
+    expectTypeOf<UseRecentSearchesReturn['removeSearch']>().parameters.toEqualTypeOf<[string]>();
+    expectTypeOf<UseRecentSearchesReturn['removeSearch']>().returns.toBeVoid();
+
+    expectTypeOf<UseRecentSearchesReturn['clearSearches']>().parameters.toEqualTypeOf<[]>();
+    expectTypeOf<UseRecentSearchesReturn['clearSearches']>().returns.toBeVoid();
+  });
+
+  it('5. verifies required fields and inferred property types', () => {
+    expectTypeOf<UseRecentSearchesReturn>().toHaveProperty('searches');
+    expectTypeOf<UseRecentSearchesReturn>().toHaveProperty('addSearch');
+    expectTypeOf<UseRecentSearchesReturn>().toHaveProperty('removeSearch');
+    expectTypeOf<UseRecentSearchesReturn>().toHaveProperty('clearSearches');
+
+    expectTypeOf<UseRecentSearchesReturn['searches']>().items.toEqualTypeOf<string>();
+
+    expect(STORAGE_KEY.length).toBeGreaterThan(0);
+    expect(MAX_SEARCHES).toBeGreaterThan(0);
+  });
+});