diff --git a/src/helper/collection.test.ts b/src/helper/collection.test.ts
new file mode 100644
index 0000000..86ac240
--- /dev/null
+++ b/src/helper/collection.test.ts
@@ -0,0 +1,106 @@
+import { expect, test } from 'vitest';
+import { buildQueryFields, filterTranslations } from './collection';
+
+test('filterTranslations - basic functionality', () => {
+    const data = [
+        {
+            id: 1,
+            translations: [
+                { languages_code: 'zh-CN', name: '中文名称1' },
+                { languages_code: 'en-US', name: 'English Name1' }
+            ]
+        },
+        {
+            id: 2,
+            translations: [
+                { languages_code: 'zh-CN', name: '中文名称2' },
+                { languages_code: 'en-US', name: 'English Name2' }
+            ]
+        }
+    ];
+
+    const result = filterTranslations<typeof data[0]>(data, 'en-US');
+    expect(result).toEqual([
+        {
+            id: 1,
+            translations: [
+                { languages_code: 'en-US', name: 'English Name1' }
+            ]
+        },
+        {
+            id: 2,
+            translations: [
+                { languages_code: 'en-US', name: 'English Name2' }
+            ]
+        }
+    ]);
+});
+
+test('filterTranslations - no matching language', () => {
+    const data = [
+        {
+            id: 1,
+            translations: [
+                { languages_code: 'zh-CN', name: '中文名称1' }
+            ]
+        }
+    ];
+
+    const result = filterTranslations<typeof data[0]>(data, 'en-US');
+    expect(result).toEqual([
+        {
+            id: 1,
+            translations: []
+        }
+    ]);
+});
+
+test('filterTranslations - no translations field', () => {
+    const data = [
+        {
+            id: 1,
+            name: 'No Translations'
+        }
+    ];
+
+    const result = filterTranslations<typeof data[0]>(data, 'en-US');
+    expect(result).toEqual(data);
+});
+
+test('filterTranslations - translations in deeper structure', () => {
+    const data = [
+        {
+            id: 1,
+            details: {
+                translations: [
+                    { languages_code: 'zh-CN', name: '中文名称1' },
+                    { languages_code: 'en-US', name: 'English Name1' }
+                ]
+            }
+        }
+    ];
+
+    const result = filterTranslations<typeof data[0]>(data, 'zh-CN');
+    expect(result).toEqual([
+        {
+            id: 1,
+            details: {
+                translations: [
+                    { languages_code: 'zh-CN', name: '中文名称1' }
+                ]
+            }
+        }
+    ]);
+});
+
+test('buildQueryFields - basic functionality', () => {
+    const config = {
+        name: 'translations.name',
+        summary: 'translations.summary',
+        description: 'translations.description',
+        type: 'product_type.translations.name'
+    };
+
+    const result = buildQueryFields(config);
+    expect(new Set(result)).toEqual(new Set(['id', 'translations.languages_code.code', 'translations.name', 'translations.summary', 'translations.description', 'product_type.translations.languages_code.code', 'product_type.translations.name']));
+});
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