Several design methods of software test cases

 Equivalence Class Division equivalence class division is mainly applicable to a single input condition, the input is a numerical type, if the input specified the input interval, can be divided into an effective equivalence class, two invalid equivalence class; If the input only specifies the input range, a valid equivalence class can be divided into an invalid equivalence class.  Boundary Value boundary value method is also suitable for a single input condition, the input type can be numeric, character, etc., the boundary to be tested includes the upper point, the next point, and the off point. third, the error speculation method is mainly the test of the design of the testing experience, testing experience, the design of the test case is also very different.　　four, causality diagram method Considering the combination of input, especially applicable to a number of input conditions related to each other and the constraints of the situation.　　Design steps: 1) list the input and output;　　2) Draw causality diagram according to input and output;　　3) The constraint and restriction are marked;　　4) Convert the causality diagram into a judgment table; 5) Design test cases according to each column of the decision table. The decision table driving method decision table is suitable for solving the combination of multiple logical conditions. The combination of various logic is listed to avoid omission.　　Duplicate operations cannot be expressed.　　The decision table includes conditional piles, condition items, action piles, and action items.　　Condition Piles: List all conditions, regardless of order;　　Condition Item: Lists the values for all possible cases of the corresponding condition;　　Action Piles: Lists possible actions, regardless of order;　　Action items: Lists the actions that are taken when the condition items are evaluated in various ways.　　Design steps: 1) determine the number of rules, conditions and the combination of each condition value;　　2) List the condition piles and action piles;　　3) List the conditions;　　4) List action items;　　5) Initialization of the decision table; 6) Rules are simplified and consolidated.

Several design methods of software test cases