Report SWE261P

Group info:

• Team Name：Endloop

• Team Memebr：Bin Guo, Xin Tan, Chao Liu

Project Description

FastJson

Github: https://github.com/SSSSam141/fastjson

• [1]. Fastjson, a library taht can be used to convert Java Objects into their JSON representation, is able to convert Json string to an equivalent Java object.

• Fastjson contain 14 packages ro provide the best performance on the server-side and android client and simeple toJSONString() and parseObject() methods to convert Java objects to JSON and vice versa. Also, it allows pre-existing unmodifiable objects to be converted to and form JSON and custom presentations for objects.

  

  ​ (Image1.1The Image shows that there is 14 packages which FastJson contain)

• [2]. LOC and Language: 

​ (Image1.2 The Image shows that the lines of code in the FastJson)

Instructions for build up

• The whole project is a library and the file structure is shown as below. In source folder (../fastjson/src), com.alibaba fastjson contains all the functions for convert different types of data or objects to JSON, and There is a test directory containing all test cases.

• How to build?

  1. Make a new directory
  2. git clone https://github.com/alibaba/fastjson
  3. Choose a IDE and then import the project to the IDE as a maven project. Then find pom.xml to reload the project

• How to run?

  1. In pom.xml, add two dependencies (android or others)

     <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.2.76</version>
     </dependency>
       <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.1.72.android</version>
     </dependency>

##Testing for FastJson

• This project is using JUnnit to do unit test, and using maven to manage the dependency and build. So all the test are written under the "test" folder, all the part that need to be tested has a corresponding test file.

• This project is using JUnnit to do unit test, and using maven to manage the dependency and build. The original project comes with test cases, which is under the "test" folder and there are in total 4 sub-folders:

  

  ​ (Image2..1 The Image shows the directory of test files)

• We can run the test case individually under IDE, or we can run the test cases using maven under the terminal mvn test run all the test case mvn -Dtest=TestCaseName run single test case

• We can also build the project using maven mvn package

• There are in total 5022 test cases, with 6 failures and 3 errors.

  

  ​ (Image2.2 The Image shows the results of test cases)

##Systematic functional testing & Partition testing:

**Following concepts summarized from slides from Professor Jones: **

• [3]. Systematic functional testing:

• Select inputs that are especially valuable.

• Usually by choosing representatives of classes that are apt to fail often or not at all. It usually isolate regions with likely failures.

• functional testing usually implies systematic testing.

Using systematic functional testing can make use of the attributes of classes we have. For example, if our purpose is to estimate the proportion of needles to hay, we can use their weight attribute for filtering. If we just test and sample randomly, it will be huge work.

• [3]. Partition testing
  • Partition
    • It is one of the basic principles of general engineering principles.
    • Divide and conquer: divied complex activities into sets of simple activities that can be tackled independently. For example: we can partition testing process into: unit, integration, system, .. testing; we can partition analysis into modeling and analyzing the model.
    • Partition specification space for testing; Partition the program structure for testing.
  • Systematic partition testing
    • Sometimes failures are sparse in the space of possibile inputs but dense in some parts of the space. Use systematic partition testing can find the failures with more chances.
  • Boundaries
    • We use data type or classes to be the boundary. Since the Fastjson have the function to convert different types of object (numbers, strings) to JSON, we can simply partition our tests by the types of the input.

Features for testing

As for this fastjson library, we choose to test the main APIs of fastjson: JSON.toJSONString and parseObject. These two APIs stand for opposite directions of process. JSON.toJSONString is serialization that converts Java Objects and different types of data (Integer, float, double, String ....) to JSON while parseObject is deserialization which converts JSON equally back to their Java Objects.

###New Junit tests generated by us:

• We are first going to test the functionality for converting different types of data to JSON since the aim of this project: Fastjson is to transfer different types of data or objects to JSON. We first test the JSON.toJSONString() method.
• Junit tests: the Junit tests are in the directory: fastjson/src/test/java/SWE261P/SWE261P_A1_Test.java
  • test_String() is used for testing String type for the function JSON.toJSONString()
  • test_Array() is used for testing int[] array type for the function JSON.toJSONString()

References

[1] https://mvnrepository.com/artifact/com.alibaba/fastjson

[2] https://github.com/alibaba/fastjson

[3] : Professor Jones slides: 2022-01-20-SWE261P-Functional_Testing.