Software Testing

a set of activities for identifying failures in a software or system to ibtain user satisfaction

Advantages

  • Effective for software quality assurance
  • Better understanding of the software
  • Different philosophy from Program Proof

Concepts

Test case

  • A set of inout values
  • Execution pre-conditions
  • expected output
  • Execution post-conditions
Test Case ID Test Scenario Test Case Pre-conditions Test Steps Test Data Expected Result Post-conditions Actual Result Status
1. Action; 2. Action

Test oracle

  • A mechanism for determining whether the program has passed or failed a test
  • $\exist t\in T \bullet P(t) ≠ R(t)$

Metamorphic Testing

Test case instantiation

Abstract paths for testing =Instantiation=> Executable test case

Process

Different testing levels

Unit/Component testing

  • Testing on components
  • Applicable to a piece of independent program
  • Usually with source code
  • Identified defects are directly fixed
  • Discovering errors at an early stage

Driver

  • A Software component or test tool that replaces a component that takes care of the control and/or calling of a software component
  • Receives testing data, transmits to tested unit, starts tested unit and prints result
  • Simplest: Main function

Stub

  • A skeletal or special-purpose implementation of a software module, used to develop or test a component that calls the stub or otherwise depends on it
  • Processes few data and returns values to the calling component
  • Simplest: assign constant values to the outputs

Example

Tree

abeh

acfi

adfi

adgjl

adgkm

adgk

Testing a

Stub b’ c’ d’

Testing h

Driver e’

Testing d

Driver a’

Stub f’ g’

Tool support

Integration testing

Big Bang integration

  • Test each unit and integrate units simultaneously
  • Disadvantages
    • Defects are difficult to isolate
    • After unit testing, drivers and stubs will not be used any more

Top-down integration

  • Test the top level first, take the unit called by top level as stubs, then test the second level, take the unit that has been tested as driver unit sequentially

1258

126

137

14

Depth-first

1258

6

37

4

Breath-first

1

234

567

8

  • Advantages

    • Isolating defects
    • Stubs can be reused for developing real components
    • Discovering design problems at an early stage

  • Disadvantages

    • Low-level components may not be fully tested

    Defensive programming

Bottom-up integration

  • Test the bottom level first, set up driver unit for it, then test the upper level, take the unit that has been tested as stub sequentially.
  • Advantages
    • Isolating defects
    • Low-level components can be fully tested since they are called by drivers avoiding defensive programming problem
  • Disadvantages
    • Design problems are detected relatively late

Sandwich integration

  • Bottom-up for operation inots
  • Top-down for logic units
  • Test the interfaces of the teo kinds

Tree

125

126

13

147

Bottom

Acceptance testing

Obtain customer or user acceptance of the software

User acceptance

Operational acceptance

Contractual acceptance

Regulatory acceptance

Alpha test

Beta test

Methods

White-box testing

Test case design based on the inner structure of the software program

Static analysis

  • Test without exectuing the program
  • NULL pointers

Dynamic analysis

  • Test code while it is running
  • Statement coverage
  • Branch coverage
  • Clause coverage
  • Combinatorial coverage

https://www.cnblogs.com/dulijuan/p/4471405.html

Statement coverage

Designing test cases that enable the execution of each statement at least once

Branch coverage

Designing test cases that enable the execution of each branch of each decision at least once

流程图 不需要四种 只要第一个每个decision就可以了

Clause coverage

Designing test cases that enable each clause to evaluate to each possible value

第二个改x