Git-Repo-Analyzer

Git-Repo-Analyzer automatically obtains fixes to the source code that developers performed to address bug/issue reports for software applications on Github.

Getting Started

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Prerequisites

• Node v9.9.0(NPM is installed with Node)
• Python v3.6.1
• Scitools Understand 4.0(Build 925)
• Must have registered email address with Understand license key

Installing

1. Make sure node and npm is installed on the system. To check run the following commands from command prompt or shell. node -v and npm -v
2. Run npm install from the directory where package.json is present. This will install the required modules present in package.json into the project directory inside node_modules directory.

Starting the Application

• Run npm start will start the application and fetch the repository details and clone the repositories in the project directory. This will generate 2 JSON files.

File Name	Purpose
RequiredData.json	JSON file which contains the output of the analyzer. The structure is explained later under Output section.
RepoData.json	JSON file which contains the Github repository details. This file and its data is used for cloning the repositories.

• Run the python script which will read the RequiredData.json and modify it to incorporate the impact for the code changes determined by SciTools Understand.

Process Flow

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The following image shows the entire flow. Please navigate to the appropriate file and function to get more details about how it is achieved.

Output

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The output present in RequiredData.json will have the following structure :

Attribute Name	Attribute of	Data Type	Purpose
PATTERN_ID	None	JSON Object	This identifies the type of pattern which is under consideration which can be any of ADD_IMPORT, REMOVE_IMPORT, CHANGE_PARAMETERS
frequency	PATTERN_ID	JSON Number	This provides the number of occurrences of the pattern with PATTERN_ID for the given number of repositories which were analyzed.
matches	PATTERN_ID	JSON Array	This array has all the data about the change which matched a particular pattern.
file	each element of matches	JSON String	This gives the file name in which the change can be found.
change	each element of matches	JSON Object	Provides details like line number, content1, content2(in case of replacement) and entity for which impact needs to be found.
ln	change	JSON Number	This provides the line number in the file at which this change is present
content1	change	JSON String	Provides the content of the change under consideration.
content2	change	JSON String	Provides the content of the change with same line number as the one under consideration.It will be present in patterns which consider replacement. If content1 is with + i.e. the content is added, then content2 is with - i.e. content is deleted and vice versa.
findImpactFor	change	JSON String	Provides the entity which can be used by Understand to find the impact of the change in the file.
pull_request	each element of matches	JSON Object	Provides the data fetched from using Github API for the pull request of the repository. It also contains the issue data fetched for the particular pull request.

Sample JSON output looks like this:

{
	 "ADD_IMPORT": {
	    "frequency": 1208,
	    "matches": [
	      {
	        "file": "interpreter/src/test/java/com/iluwatar/interpreter/ExpressionTest.java",
	        "change": {
	          "ln": 26,
	          "content1": "+import org.junit.jupiter.api.TestInstance;",
	          "findImpactFor": "TestInstance"
	        },
	        "pull_request": {
				...
			}
		 }	
		...
		]
	}
	"CHANGE_PARAMETERS": {
    	"frequency": 59,
	    "matches": [
	      {
	        "file": "prototype/src/main/java/com/iluwatar/prototype/App.java",
	        "change": {
	          "ln": 55,
	          "content1": "-    factory = new HeroFactoryImpl(new ElfMage(), new ElfWarlord(), new ElfBeast());",
	          "content2": "+    factory = new HeroFactoryImpl(new ElfMage(\"cooking\"), new ElfWarlord(\"cleaning\"), new ElfBeast(\"protecting\"));",
	          "findImpactFor": "    factory = new HeroFactoryImpl"
	        },
	        "pull_request": {
				...
			}
		 }	
		...
		]
	}
}	

Built With

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• Node - Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.
• Understand - Helps to quickly and easily understand and visualize complex code, perform impact analysis, and deliver powerful metrics.
• Octokit - GitHub REST API client for Node.js

Authors

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• Amrish Jhaveri
• Chinmay Gangal