Top 10 negative test cases

Negative test cases used for testing the application, subject to receipt on his entry "incorrect" data. Such test cases should always be used during testing. Below are the ten most popular negative test scenarios:

Embedded Single Quote - Most SQL databases, there are problems in the presence of single quotes in the query (eg, Jones's car).
Use single quotes when checking each input field working with the database.

Required Data Entry - In the specification of your application should be clearly defined fields requiring mandatory data entry.
Check that the forms that have fields defined as mandatory for entry, can not be maintained in the absence of data in them.

Field Type Test - In the specification of your application should be clearly defined data types for each of the fields (fields date / time, numeric fields, fields for entering a telephone number or postal code, etc.)
Check that each of the fields allows you to enter or store data only certain specification of the type (for example, the application should not allow you to enter or maintain letters or special characters in numeric fields).

Field Size Test - In the specification of your application should be clearly defined maximum number of characters in each of the fields (for example, the number of characters in a field with a user name should not exceed 50).

To check that your application can not adopt or maintain more characters than specified. Do not forget that these fields should not only function correctly, but also to warn the user about the limitations, for example, with explanatory text boxes or error messages.

Numeric Bounds Test - Numeric field of your application may be limited allowable numeric values. These constraints can be specified in the specification of your application or arising from the logic of the program (for example, if you test the functionality associated with the accrual of interest on the account, it is logical to assume that the accrued interest can not take a negative value).

Check that the application displays an error message if the values fall outside the acceptable range (for example, the error message should appear when you enter a value of 9 or 51 in a field with valid values range from 10 to 50, or when you enter a negative value in the field whose values must be positive).

Numeric Limits Test - Most databases and programming languages define the numerical values of the variables with a certain type (eg, integer or long integer), which, in turn, have limited allowable numeric values (eg, integer values must be in the range -32768 32767, a long integer from -2147483648 to 2147483647).
Check the boundary values of the variables used for numeric fields, the boundary values which are not clearly defined specification.

Date Bounds Test - Very often in applications, there are logical limits to the fields containing the date and time. For example, if you check the box containing the user's date of birth, it is only logical to ban entry not yet due date (ie the date in the future), or restriction on the entry date is different from that of today more than 150 years.

Date Validity - Date fields should always be checking the validity of the entered values (eg, 10/31/2009 - not valid date). Also, do not forget about checking dates in leap years (years divisible by 4 m and multiples of 100 and 400 at the same time - a leap).

Web Session Testing - Many web applications use a browser session to track user logged into the system, application-specific application settings for a particular user, etc. At the same time, many of the features of the system can not or should not work without login. Check that the functionality or pages that are behind a password, not user is not authenticated.

Performance Changes - For each new product release is conducting a series of performance tests (for example, the rate of additions, deletions or changes of various elements on the page). Compare the results with tests of performance of previous versions. This practice will allow you to advance to identify potential performance problems due to code changes in new versions of the product.