diff --git a/src/api/bookshop/index.test.ts b/src/api/bookshop/index.test.ts
new file mode 100644
index 0000000..d4bacb3
--- /dev/null
+++ b/src/api/bookshop/index.test.ts
@@ -0,0 +1,63 @@
+import { describe, expect, test, vi } from 'vitest'
+import { getFindParamsFilter } from './index'
+
+// deepseek r1 - plan reason
+// antrhopic - claude
+
+vi.mock('helpers/config/mongodb', () => ({
+  clientPromise: Promise.resolve({
+    db: vi.fn(),
+    connect: vi.fn()
+  })
+}))
+
+describe('getFindParamsFilter', () => {
+  test('should return empty object for empty search', () => {
+    const result = getFindParamsFilter('{}')
+    expect(result).toEqual({})
+  })
+
+  test('should create name filter with regex', () => {
+    const result = getFindParamsFilter('{"name":"Book Store"}')
+    expect(result).toEqual({
+      name: { $regex: 'Book Store', $options: 'si' }
+    })
+  })
+
+  test('should create ISO filter', () => {
+    const result = getFindParamsFilter('{"iso":"US"}')
+    expect(result).toEqual({
+      iso: 'US'
+    })
+  })
+
+  test('should create city filter with regex', () => {
+    const result = getFindParamsFilter('{"city":"New York"}')
+    expect(result).toEqual({
+      city: { $regex: 'New York', $options: 'si' }
+    })
+  })
+
+  test('should filter bookshops with website', () => {
+    const result = getFindParamsFilter('{"website":"with"}')
+    expect(result).toEqual({
+      site: { $exists: true }
+    })
+  })
+
+  test('should filter bookshops without website', () => {
+    const result = getFindParamsFilter('{"website":"without"}')
+    expect(result).toEqual({
+      site: { $exists: false }
+    })
+  })
+
+  test('should combine multiple search criteria', () => {
+    const result = getFindParamsFilter('{"name":"Book","city":"London","website":"with"}')
+    expect(result).toEqual({
+      name: { $regex: 'Book', $options: 'si' },
+      city: { $regex: 'London', $options: 'si' },
+      site: { $exists: true }
+    })
+  })
+})
diff --git a/src/api/bookshop/index.ts b/src/api/bookshop/index.ts
index 3403d16..ba4999a 100644
--- a/src/api/bookshop/index.ts
+++ b/src/api/bookshop/index.ts
@@ -4,7 +4,7 @@ import type { ApiQuery } from 'types/api'
 import type { SearchBookshopsApi } from 'types/search'
 
 
-const getFindParamsFilter = (search: string) => {
+export const getFindParamsFilter = (search: string) => {
   const searchData = JSON.parse(search)
 
   const searchFilter: SearchBookshopsApi = {}