diff --git a/packages/xml-locales/src/__snapshots__/xml-locales.test.ts.snap b/packages/xml-locales/src/__snapshots__/xml-locales.test.ts.snap
new file mode 100644
index 0000000..5816ae9
--- /dev/null
+++ b/packages/xml-locales/src/__snapshots__/xml-locales.test.ts.snap
@@ -0,0 +1,77 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`XmlLocales > XmlLocales constructor > constructor should parse xml data 1`] = `
+XmlJsonData {
+  "resources": {
+    "string": [
+      {
+        "#text": "value1",
+        "key_name": "key1",
+      },
+    ],
+  },
+}
+`;
+
+exports[`XmlLocales > XmlLocales constructor > should return json object 1`] = `
+XmlJsonData {
+  "resources": {
+    "#text": "
+  
+  
+",
+    "string": [
+      {
+        "#text": "value1",
+        "key_name": "key1",
+      },
+      {
+        "#text": "value2",
+        "key_name": "key2",
+      },
+    ],
+  },
+}
+`;
+
+exports[`XmlLocales > should return json object 1`] = `
+XmlJsonData {
+  "resources": {
+    "#text": "
+  
+  
+",
+    "string": [
+      {
+        "#text": "value1",
+        "key_name": "key1",
+      },
+      {
+        "#text": "value2",
+        "key_name": "key2",
+      },
+    ],
+  },
+}
+`;
+
+exports[`XmlLocales > should return xml string 1`] = `
+"<resources>
+  <string name=\\"key1\\">value1</string>
+  <string name=\\"key2\\">value2</string>
+</resources>"
+`;
+
+exports[`XmlLocales > to XML > should return xml string with formatting 1`] = `
+"<resources>
+  <string name=\\"key1\\">value1</string>
+  <string name=\\"key2\\">value2</string>
+</resources>"
+`;
+
+exports[`XmlLocales > to XML > should return xml string without formatting 1`] = `
+"<resources><string name=\\"key1\\">value1</string><string name=\\"key2\\">value2</string>
+  
+  
+</resources>"
+`;
diff --git a/packages/xml-locales/src/utils/__snapshots__/xml.test.ts.snap b/packages/xml-locales/src/utils/__snapshots__/xml.test.ts.snap
new file mode 100644
index 0000000..8cfb998
--- /dev/null
+++ b/packages/xml-locales/src/utils/__snapshots__/xml.test.ts.snap
@@ -0,0 +1,15 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`XmlParser > should format xml string 1`] = `
+"<resources>
+  <string name=\\"key1\\">value1</string>
+  <string name=\\"key2\\">value2</string>
+</resources>"
+`;
+
+exports[`XmlParser > should parse json to xml 1`] = `
+"<resources><string name=\\"key1\\">value1</string><string name=\\"key2\\">value2</string>
+  
+  
+</resources>"
+`;
diff --git a/packages/xml-locales/src/utils/helpers.test.ts b/packages/xml-locales/src/utils/helpers.test.ts
new file mode 100644
index 0000000..5540ccf
--- /dev/null
+++ b/packages/xml-locales/src/utils/helpers.test.ts
@@ -0,0 +1,49 @@
+import { describe, expect, test } from 'vitest';
+
+import {
+	checkKeyValueExist,
+	checkXmlKey,
+	replaceXmlNodeValue
+} from './helpers.js';
+
+const xmlData = {
+	resources: {
+		string: [
+			{
+				key_name: 'key1',
+				'#text': 'value1'
+			},
+			{
+				key_name: 'key2',
+				'#text': 'value2'
+			}
+		]
+	}
+};
+
+describe('checkXmlKey', () => {
+	test('should return true if key exist', () => {
+		expect(checkXmlKey(xmlData, 'key1')).toBe(true);
+	});
+
+	test('should return false if key does not exist', () => {
+		expect(checkXmlKey(xmlData, 'key3')).toBe(false);
+	});
+});
+
+describe('checkKeyValueExist', () => {
+	test('should return true if key value exist', () => {
+		expect(checkKeyValueExist('value1', xmlData.resources.string)).toBe(true);
+	});
+
+	test('should return false if key value does not exist', () => {
+		expect(checkKeyValueExist('value3', xmlData.resources.string)).toBe(false);
+	});
+});
+
+describe('replaceXmlNodeValue', () => {
+	test('should replace the value of the key', () => {
+		const newXmlData = replaceXmlNodeValue(xmlData, 'key1', 'value3');
+		expect(newXmlData.resources.string[0]?.['#text']).toBe('value3');
+	});
+});
diff --git a/packages/xml-locales/src/utils/xml.test.ts b/packages/xml-locales/src/utils/xml.test.ts
new file mode 100644
index 0000000..e77e317
--- /dev/null
+++ b/packages/xml-locales/src/utils/xml.test.ts
@@ -0,0 +1,87 @@
+import { describe, expect, test } from 'vitest';
+
+import {
+	checkKeyValueExist,
+	checkXmlKey,
+	replaceXmlNodeValue
+} from './helpers.js';
+import { XmlJsonData, XmlParser } from './xml.js';
+
+const xmlData = `
+<resources>
+  <string name="key1">value1</string>
+  <string name="key2">value2</string>
+</resources>
+`;
+
+describe('XmlParser', () => {
+	test('should parse xml to json', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		expect(jsonData).toMatchObject({
+			resources: {
+				string: [
+					{
+						key_name: 'key1',
+						'#text': 'value1'
+					},
+					{
+						key_name: 'key2',
+						'#text': 'value2'
+					}
+				]
+			}
+		});
+	});
+
+	test('should parse json to xml', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		const xmlString = xmlParser.jsonToXml(jsonData);
+		expect(xmlString).toMatchSnapshot();
+	});
+
+	test('should format xml string', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		const xmlString = xmlParser.jsonToXml(jsonData);
+		const formattedXmlString = xmlParser.formate(xmlString);
+		expect(formattedXmlString).toMatchSnapshot();
+	});
+});
+
+describe('XmlJsonData', () => {
+	test('should check if key exist', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		const xmlJsonData = new XmlJsonData(jsonData);
+
+		expect(checkXmlKey(xmlJsonData, 'key1')).toBe(true);
+		expect(checkXmlKey(xmlJsonData, 'key3')).toBe(false);
+	});
+
+	test('should check if key value exist', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		const xmlJsonData = new XmlJsonData(jsonData);
+		expect(checkKeyValueExist('value1', xmlJsonData.resources.string)).toBe(
+			true
+		);
+		expect(checkKeyValueExist('value3', xmlJsonData.resources.string)).toBe(
+			false
+		);
+	});
+
+	test('should replace the value of the key', () => {
+		const xmlParser = new XmlParser();
+		const jsonData = xmlParser.xmlToJson(xmlData);
+		const xmlJsonData = new XmlJsonData(jsonData);
+
+		expect(
+			checkKeyValueExist(
+				'value3',
+				replaceXmlNodeValue(xmlJsonData, 'key1', 'value3').resources.string
+			)
+		).toBe(true);
+	});
+});
diff --git a/packages/xml-locales/src/xml-locales.test.ts b/packages/xml-locales/src/xml-locales.test.ts
new file mode 100644
index 0000000..1ea7624
--- /dev/null
+++ b/packages/xml-locales/src/xml-locales.test.ts
@@ -0,0 +1,132 @@
+import { describe, expect, test } from 'vitest';
+
+import { XmlLocales } from './xml-locales.js';
+
+const xmlData = `<resources>
+  <string name="key1">value1</string>
+  <string name="key2">value2</string>
+</resources>`;
+
+const oneStringXmlData = `<resources>
+  <string name="key1">value1</string>
+</resources>`;
+
+describe('XmlLocales', () => {
+	describe('add', () => {
+		test('should add new node', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			const jsonXml = xmlLocales.add({ key: 'key3', value: 'value3' }).toJSON();
+			const newNode = jsonXml.resources.string[2];
+
+			expect(newNode?.key_name).toBe('key3');
+			expect(newNode?.['#text']).toBe('value3');
+		});
+
+		test('should replace the value of the key', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			const jsonXml = xmlLocales.add({ key: 'key1', value: 'value3' }).toJSON();
+			const newNode = jsonXml.resources.string[0];
+
+			expect(newNode?.key_name).toBe('key1');
+			expect(newNode?.['#text']).toBe('value3');
+		});
+	});
+
+	describe('remove', () => {
+		test('should remove a node of the key', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.deleteByKey('key1');
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.['#text']).toBe('value2');
+		});
+
+		test('should remove a node of the value', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.deleteByValue('value1');
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.['#text']).toBe('value2');
+		});
+
+		test('not found key or value', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.deleteByKey('key3');
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.['#text']).toBe('value1');
+		});
+	});
+
+	describe('sort', () => {
+		test('should sorted by "asc"', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.sort('asc');
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.key_name).toBe('key1');
+		});
+
+		test('should sorted by "desc"', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.sort('desc');
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[1]?.key_name).toBe('key1');
+		});
+	});
+
+	describe('update', () => {
+		test('should update key', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.update({ oldValue: 'key1', newValue: 'newKey1' });
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.key_name).toBe('newKey1');
+		});
+
+		test('should update value', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			xmlLocales.update({ oldValue: 'value1', newValue: 'newValue1' });
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml.resources.string[0]?.['#text']).toBe('newValue1');
+		});
+	});
+
+	describe('XmlLocales constructor', () => {
+		test('should throw error if xml data is not defined', () => {
+			expect(() => new XmlLocales()).toThrow('XML data is not defined');
+		});
+
+		test('constructor should parse xml data', () => {
+			const xmlLocales = new XmlLocales(oneStringXmlData);
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml).toMatchSnapshot();
+		});
+
+		test('should return json object', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			const jsonXml = xmlLocales.toJSON();
+
+			expect(jsonXml).toMatchSnapshot();
+		});
+	});
+
+	describe('to XML', () => {
+		test('should return xml string with formatting', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			const xmlString = xmlLocales.toXML();
+
+			expect(xmlString).toMatchSnapshot();
+		});
+
+		test('should return xml string without formatting', () => {
+			const xmlLocales = new XmlLocales(xmlData);
+			const xmlString = xmlLocales.toXML(false);
+
+			expect(xmlString).toMatchSnapshot();
+		});
+	});
+});