Forem: pavlovic265

Spring cleaning Git branches

pavlovic265 — Sun, 01 Aug 2021 15:57:32 +0000

When working on multiple repositories and branches, testing branches, backing them up, code reviewing, playing around branches, etc. I find myself in a situation where it pains me when the time for clean-up comes.

In order to delete branches, I need to google the command. However, it might not always work as I want. For example, if I want some branches to be saved I need to update the command and restart the terminal, or if I want to save few additional branches with different naming convention I again need to update the command and restart the terminal... you get the point.

Additionally, I wanted to create a more permanent solution for all of the repositories. Here is the link to the repository: remove-git-branch. Let me try and explain what I did in the script the best I can.

My goal was to have a flexible script that does deletion based on arguments.

In the repository linked above you will find the script remove-git-branches.sh.

for i in "$@"; do
  case $i in
    -b=*|--branch=*)
      BRANCHES="${i#*=}"
      shift # past argument=value
      ;;
    -p=*|--pattern=*)
      PATTERN="${i#*=}"
      shift # past argument=value
      ;;
    -a|--all)
      ALL=".*"
      shift # past argument=value
      ;;
    -e=*|--exclude=*)
      EXCLUDE="${i#*=}"
      shift # past argument=value
      ;;
    -c|--check)
      CHECK="true"
      shift # past argument=value
      ;;
    -f|--force)
      FORCE="true"
      shift # past argument=value
      ;;
    -h|--help)
    echo "usage: remove-git-branch  [-b=<pattern> | --branch=<pattern>] [-p=<pattern> | --pattern=<pattern>]
                [-a | --all] [-h | --help]"
      echo "-b (--branch) - Branches to remove separated by ','. It has priority over pattern."
      echo "-p (--pattern) - Regex pattern to define witch branches should be removed."
      echo "-a (--all) - Remove all branches, expect master, **main, and current."
      echo "-e (--exclude) - Branches to exclude from deleting."
      echo "-c (--check) Print branches that will be deleted. But DOES NOT delete them."
      echo "-f (--force) Force delete branches, even if it has unmerged changes."
      echo "-h (--help) - Available flags."
      exit 1;
      ;;
    *)
      # unknown option
      ;;
  esac
done

One of the first things you will notice is a for-in loop. This loop will collect all the arguments when a script is called. You can thank Bruno Bronosky stackoverflow answer for this piece of code.

if [[ $EXCLUDE ]]; then
     SPLIT_EXCLUDE=$(echo $EXCLUDE | tr "," "|");
     EXCLUDE="^($EXCLUDE_DEFAULT|$SPLIT_EXCLUDE)$"
    else 
     EXCLUDE="^($EXCLUDE_DEFAULT)$"
    fi

EXCLUDE, as the name suggests, excludes branches from deleting. By default, it always excludes master, main and current branches which is represented by EXCLUDE_DEFAULT.

if [[ $BRANCHES ]]; then
 SPLIT_BRANCHES=$(echo $BRANCHES | tr "," "|");
 DELETE_BRANCHES="^($SPLIT_BRANCHES)$"
fi

Here I am checking if the variable BRANCHES is not empty. If not empty, replacing is done in the same way as EXCLUDE.

if [[ $PATTERN ]]; then
 DELETE_PATTERN="$PATTERN"
fi

This one is here just for taking the value from the PATTERN.

if [[ $DELETE_PATTERN ]] && [[ $DELETE_BRANCHES ]]; then
 DELETE="(($DELETE_BRANCHES)|($DELETE_PATTERN))"
elif [[ $DELETE_PATTERN ]]; then
 DELETE=$DELETE_PATTERN
elif [[ $DELETE_BRANCHES ]]; then
 DELETE=$DELETE_BRANCHES
fi

There are three ways of deleting: by passing branches, by passing pattern, or combined. The first IF statement would merge branch and pattern meaning we passed both of them, the second one would pass only pattern, and the third one would pass only branches.

if [[ $ALL ]]; then
 DELETE="$ALL"
fi

Next IF statement is ALL. It removes all the local branches we have. Again, the master, the main, and the current branch will not be deleted.

if [[ $CHECK ]]; then
     git branch | awk '{gsub(/^[ \t]+| [ \t]+$/,""); print $0 }' | egrep -v "$EXCLUDE" | egrep "$DELETE"
    elif [[ $FORCE ]]; then
     git branch | awk '{gsub(/^[ \t]+| [ \t]+$/,""); print $0 }' | egrep -v "$EXCLUDE" | egrep "$DELETE" | xargs git branch -D
    else
     git branch | awk '{gsub(/^[ \t]+| [ \t]+$/,""); print $0 }' | egrep -v "$EXCLUDE" | egrep "$DELETE" | xargs git branch -d
    fi

The last block of code is where the command runs. There are few things that are happening.

git branch gets a list of all branches
awk '{gsub(/^[ \t]+| [ \t]+$/,""); print $0 }' removes empty spaces on both sides of the branch
egrep -v "$EXCLUDE" prints all the branches that DO NOT match pattern, -v flag does that.
egrep "$DELETE" prints all the branches that DO match pattern.
- If we pass the check flag ($CHECK), deletion will not happen but the branch name that was supposed to be deleted will be printed, it can be thought of as a sanity check.
- If we pass the force flag ($FORCE), deletion will happen but it will additionally delete a branch that was not merged.
- The last ELSE statement is a "safe" option that prevents deletion of the branch if it has unmerged changes.

References

Deploying create-react-app one-page application to GitHub Pages

pavlovic265 — Sat, 03 Jul 2021 16:30:38 +0000

I wanted to create a one-page application for trying out Github Pages. The issue I had was constantly getting error 404 or readme.md. I read a lot of articles to find a way to solve those issues and get the default create-react-app page shown. However, I failed to find a ready-to-go solution that worked for me.

So here I will describe what I did to make my GitHub pages work with my repository. I skipped creating a GitHub repo, cloning the project, and running create-react-app to create a project. I assume you have already done that before you follow my steps.

Please, keep in mind that if you design an application with multiple pages additional configuration might be needed. My application contains only one page, this is why I did not use react-router.

So, let me start.

Steps 1:

I remove node_modules folder and reinstall npm modules. This is optional and should be done if deployment haven't worked for you previously (e.g. the following error appeared: 'fatal: Couldn't find remote ref refs/heads/gh-pages').

Step 2:

It was pointed out in the sources I read that GitHub pages do not play very well with SPA so I needed to do few changes to package.json file.

First, I install gh-pages as devDependencies.

npm i --save-dev gh-pages // -> using npm
yarn add -D gh-pages // -> using yarn

gh-pages module helps with deploying the application and it creates a branch where we want to deploy our code. That is why there is no need to create a branch manually.

Now I need to add in package.json file.

{
  "homepage": "https://[GITHUB_USER].github.io/[GITHUB_REPOSITORY_NAME]"
}

This will be URL of the project homepage.

After that, I add the following lines in the scripts section in package.json.

{
  "predeploy": "npm run build", // or yarn build
  "deploy": "gh-pages -b gh-deploy -d build",
}

-b name of the branch I am pushing to, the default branch is gh-pages
-d Base directory for source files

When I run deploy it automatically runs predeploy first. Also, the code that was built with predeploy command is deployed to thegh-deploy branch.

The final result should look like this:

{
  "homepage": "https://[GITHUB_USER].github.io/[GITHUB_PROJECT]",
  ...
  "scripts": {
    "predeploy": "npm run build", // or yarn build
    "deploy": "gh-pages -b gh-deploy -d build",
    ...
  },
  ...
  "devDependencies": {
    "gh-pages": "^3.2.3"
  },
  ...
}

Step 3:

Open GitHub and open your repository.
Click Settings.
Click Pages.
Select gh-deploy branch from dropdown.
Click Save.
Wait for deployment to finish and then check out the app.

This is one of the ways you can deploy your one-page application to GitHub pages. Hopefully, it will help you if you find yourself struggling with the same issues.