public void TestDeserialize() { string json = "{\"Property1\":\"test123\",\"Property2\":5}"; string file = "test.json"; string path = "path1"; _fileServiceMock.Setup(f => f.PathCombine(path, file)).Returns(file); _ioService.SetPath(path); _fileServiceMock.Setup(f => f.ReadAllText(file)).Returns(json); var jsonTestClass = _ioService.DeserializeFileToJson <TestSerializeJsonClass>(file); Assert.AreEqual("test123", jsonTestClass.Property1); Assert.AreEqual(5, jsonTestClass.Property2); }