知道什么導致測試失敗很重要,因此我們在斷言里添加失敗的信息提示。
單元測試和代碼重用
回看那27個測試用例,我們可以斷定設置FirstName為null或者空串應該也需求同樣的測試。因此我們可以擴展成:
[TestMethod]
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public void Person_FirstName_Set_Empty() { Person_FirstName_Set_Invalid(String.Empty); } |
[TestMethod]
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public void Person_FirstName_Set_Null() { Person_FirstName_Set_Invalid( null ); } public void Person_FirstName_Set_Invalid(string firstName) { var person = new Person( "Adam" , "Smith" ); var eventAssert = new PropertyChangedEventAssert(person); var errorsChangedAssert = new ErrorsChangedEventAssert(person); var changeAssert = new ChangeAssert(person); Assert.IsFalse(person.IsChanged, "Test setup failed, IsChanged is not false" ); Assert.AreEqual( "Adam" , person.FirstName, "Test setup failed, FirstName is not Adam" ); Assert.AreEqual( "Smith" , person.LastName, "Test setup failed, LastName is not Smith" ); person.FirstName = firstName; Assert.AreEqual(firstName , person.FirstName, "FirstName setter failed" ); Assert.AreEqual( "Smith" , person.FullName, "FullName not updated with FirstName changed" ); Assert.IsTrue(person.IsChanged, "IsChanged flag was not set when FirstName changed" ); eventAssert.Expect( "IsChanged" ); eventAssert.Expect( "FirstName" ); eventAssert.Expect( "FullName" ); Assert.IsTrue(person.HasErrors, "HasErrors should have remained false" ); errorsChangedAssert.ExpectCountEquals( 1 , "Expected an ErrorsChanged event" ); changeAssert.AssertOnlyChangesAre( "FirstName" , "FullName" , "IsChanged" , "HasErrors" ); } |