Git Compare

Compare 2 git commits and prints out the difference between those commits

How to Run

Using Go

You can build the application if you have go installed in your machine. follow the instructions below to build and run

1- Clone the application

git clone https://github.com/msolimans/gitcomp

2- Build and run

go run ./cmd/main.go 

Using Docker

1- Clone the application

git clone https://github.com/msolimans/gitcomp

2- Build docker image

docker build -t gitcomp .

3- Run

docker run -it --rm gitcomp 

Using Makefile

Makefile was added to simplify building and running unit testing in local machine and within CI/CD pipelines

To build locally using installed go

make REVISION_NUM=sha build

To build using docker

make REVISION_NUM=sha dbuild

To run unit tests

make test 

CLI commands and parameters:

Command	Flag(s)	Short Flag(s)	Description	Required
help	help	-h	Prints help message
version		-h	Prints version details
compare			Compare 2 git commits
	--token	-t	Personal Access Token	Y
	--org	-o	Organization or owner	Y
	--repo	-r	Repostiry name	Y
	--head	-d	Head commit sha	Y
	--base	-b	Base commit sha	Y

Notes

• structs were auto-generated using https://mholt.github.io/json-to-go/ and some of them were extended with a simple string overrides in types_ext.go.
• I used oath2.NewClient to generate http client then passed that client inside GitClient. we can also pass the token via Bearer Token in Authorization header as documented here https://docs.github.com/en/rest/commits/commits#compare-two-commits

Assumptions

• There was no requirement stating anything about pagination but I can follow https://docs.github.com/en/rest/guides/traversing-with-pagination and do that if this is necessary.
• Unit Testing were done based on mocking http test server along with a mock handler that memics the same responses coming from GitHub. GitClient was implemented in away that it can call real or mock Github APIs.
• In case there's a need to change test cases to real GitHub api calls, please let me know and I can adjust that accordingly.
• Http Client returns standard httpClient, enhancement can be done by a simple wrapper within which we can add extra fields like timeouts, unified headers, user agents or logging raw request/response details.
• Nothing mentioned logging that's why I simply used fmt.Println. I am pretty familiar with zap and Logrus
• Requirments for Github actions were not clear enough, I enabled CI for opened or reopened PRs only however I can add pushes to master branch however direct pushes can be avoided/prevented from branch protection in repository settings.

Enhancements

• Add goreleaser to package
• Docker build tag can be enhanced with :date +%s
• Builds and unit tests can be run in parallel with matrix strategy