Pushing, Pulling, & Merging

Local changes are synced to remote repositories (in GitHub) using actions called pulling, pushing, and merging.

Pushing

Changes you’ve made locally can be added to the remote repo by pushing. After making a commit(s), invoke the command to upload and apply your local changes, making them available to everyone else.

git push

Pushing A Branch For The First Time

If the branch you’re on does not exist in GitHub yet, git will prompt you to set up a remote version with an ominous message:

fatal: The current branch <branch-name> has no upstream branch.
To push the current branch and set the remote as upstream, use

git push --set-upstream origin <branch-name>

Just copy and paste the last line.

Pulling

If a branch on your local machine is out of date, you can update it with the pull command. Doing so will download and apply any commits that you don’t have locally.

git pull

Merging

Branches are combined by merging them together. The process is carried out automatically by git. You specify a source and a destination, and git will algorithmically combine all of the commits from both branches. The source branch will remain unchanged, and the destination branch will be updated. You can safely delete a source branch after it’s been merged.

Merging can be done in GitHub, or from the terminal. At Upstatement, we usually do it in GitHub.

Merge Conflicts

Sometimes two branches contain conflicting changes that git can’t automatically resolve, causing a merge conflict. We try to mitigate them by planning, isolating, and keeping branches small, but they’re ultimately unavoidable.

When GitHub encounters a merge conflict, it will prevent merging until you update the source branch to remove the conflict, or make a resolution in GitHub’s web editor.